Name: Kim
Username: Kimlbube2000
Subject: Consciousness and Hypnosis
Date: Thu May 4 16:31:08 EDT 2000
Comments:
Kimberly Bibbo

Final Paper

May 1, 2000

Hypnosis Hype or Altered Consciousness?

Most portrayals of hypnosis encountered in the media show it as a joke. Usually a watch is waved, and someone falls into a deep sleep and does what they are told. All of the hype aside, what is it that hypnosis actually does for consciousness? Does it indeed alter or change our state of consciousness, or is it more of a relaxation method? Currently, there are two schools of debate on the topic; the state view, that claims consciousness is altered, and the non-state view that says hypnosis is a type of relaxation and not an actual change of consciousness. I will assert here that the evidence I found thus far is much more convincing that hypnosis does indeed alter consciousness.

Just ten years ago, I myself underwent hypnosis, and subsequently was taught the art of self-hypnosis. Perhaps the best description of the experience is that if you are open-minded to alternative methods of thinking, the techniques used are extremely helpful. The uses in numbing pain and refocusing attention to control the body are quite unique. Prior to undergoing major surgery, I learned how to ignore almost any other environmental stimuli and focus on something else of my choosing. Objectively, it is difficult to say if that kind of self-induced trance is actually an alteration of consciousness. It is true that pain could no longer be felt once in my trance or altered state, but I can not account for whether or not I left consciousness to a different state. It was also true that I did not notice the passing of time or real world events, but again, is this kind of trance a different consciousness?

The course started out with a book defining consciousness by Damasio. Damasio’s model was contrary to most traditional definitions of consciousness, including the ones I read in these particular reports on hypnosis and consciousness. His model of consciousness and way of thinking were unique, and did not address the ideas of alertness and awareness as much as the different levels of emotion processing that signify consciousness. On the topic of hypnosis and consciousness, Damasio spoke of pain by asserting that hypnotic suggestions worked best when aimed at emotions of pain, as opposed to the pain sensation itself. He felt that the hypnosis was beneficial on an emotional, but not physiological level (Damasio 75). Most state theorists would agree with him that the emotional state is altered by hypnosis in regards to pain. The non-state theorists might not feel the same given Damasio’s arguments. Let me assess my findings of the state views in order to show the comparison between the two points of view.

The traditional state view claims that consciousness is indeed altered when hypnosis takes place. Although not directly stated as such by all theorists in this view, one particular psychologist describes the experience as two sides of a trap door located in the brain (Yarnell 2). He says the hypnotic state allows someone under hypnosis to open the trapdoor to his or her subconscious mind. Essentially, this particular state view asserts that hypnosis can be likened to the state of sleep in the sense that the subconscious mind, just below the conscious mind, is opened. His argument for the physiological change that allows this to occur is that under deep relaxation, the brain waves change to alpha waves, just like in sleep, that allow the glimpse into the subconscious mind. More important in the state view are the modern implications for the subconscious release of the mind. In the everyday application of psychology, hypnosis aids in self-esteem and confidence suggestions, improving performance at certain tasks, overcoming phobias, and other suggestions that aid in the cessation of activities such as smoking or overeating (Yarnell 3). As long as the persons undergoing hypnosis are open to suggestion and have the proper motivation for undergoing hypnosis, the results are reported as highly successful. In addition, it is key to emphasize repetition in treatment of above listed goals. The question still remains as to what the state theorists see as altered consciousness. Typically, the definition of consciousness involves measuring cognitive structure and function of thoughts. Within this broad idea are the areas of perception, cognition, attention, memory, emotion, and awareness (Sanders 299). The imagery presented to the patient undergoing hypnosis is said to play a large role in altered consciousness. Obviously, as seen through Damasio, the definitions of “consciousness” vary greatly. But the view forwarded by state view theorists follows more traditional ideas and guidelines that focus on the above listed factors. The concepts of attention, memory, and awareness are the primary components measured by state theorists to assess levels of consciousness. These aspects are the most significant since while under hypnosis, components of the subconscious are said to be let into the consciousness of the mind, hence suggestions to help quit smoking or loose weight. The person’s susceptibility to new ideas fall under the categories of attention and awareness. The psychologists performing the hypnosis can assess these features through standard tests of awareness, attention, and memory. The whole interchange is described as a “dreamlike dialogue of conscious and unconscious ideation” (Sanders 301).

The state view theorists have set out very definite guidelines for views on hypnosis and consciousness, as discussed above. That leaves the non-state theorists. Two researchers ran an experiment to see if consciousness was indeed altered when hypnosis is performed. Their arguments against consciousness were that no physiological markers were present in the hypnotic state and that all suggestions made under hypnotic induction can be performed just as well and successfully under deep relaxation (Council and Kenny, 657). The experiment involved four conditions to challenge the hypotheses that hypnotic induction causes altered states of consciousness and that the altered states lead to higher suggestibility: traditional hypnotic induction, alert hypnotic induction, relaxation training, and imagination training (Council and Kenny, 658). All four conditions of the experiments adhered closely with accepted hypnotic/relaxation techniques. Subjects were placed in the conditions, and then discussed their experience and thinking, the experience of body, and sense of time in self-reports. These reports were either taken while under hypnosis, or immediately following. Experts from both state and non-state viewpoints were brought in to judge self-reports and see if they could tell the differences between conditions (Council and Kenny, 658). According to the results, the judges, experts in the field of hypnosis, were unable to reliably discriminate the self-reports of subjects under self-hypnosis compared to those who were not (Council and Kenny, 661). One glaring error within this study is that the authors themselves admit that the data did not disprove the altered state hypothesis. They claim it is not falsifiable because it is possible that reliable physiological, behavioral, or self-report of a hypnotic trance can be discovered. Therefore, they have nothing specific to disprove the theory that hypnosis alters consciousness. A theory can not hold sound on the premise that something beneficial might be discovered in the future.

I do not propose that the altered consciousness theory should be believed only because there is no direct evidence to the contrary. However, the history of research done on hypnosis and altered consciousness dates back to the 1930’s, and has been done very extensively in the 70’s and 80’s by Erikson and many others (his name the most prominent found in my searches). The studies to the contrary are perhaps not as well established as support for altered consciousness, one of my reasons for taking the altered consciousness view on the matter. In addition, the experience I underwent definitely felt like a separate consciousness, should consciousness be defined as attention and alertness. Compared to everyday attention and alertness, the hypnosis I underwent felt detached from every day reality, and definitely opened up the same types of emotions and feelings experienced at that time right before or after sleep when dreams and thoughts flood into the mind. In addition, I do not see how certain trances such as “the zone” for athletes or “driving trance” for the majority of Americans can fall under the category of every day consciousness. Perhaps the argument is wholly dependent on the particular definition of consciousness used in the debate. But in terms of self-report for things such as driving trances or being in “the zone,” there is definitely something that occurs that is not covered in the realm of daily experience of consciousness.

References:

Council, Kenny. ”Expert Judgements of Hypnosis From Subjective Reports.” Journal of Abnormal Psychology, 101, 657-662.

Damasio, Antonio. The Feelling of What Happens. New York: Harcort Brace and Company, 1999.

Sanders, Shirley. The Book of the Self. New York: New York University Press, 1988.

Yarnell, Thomas. “About Hypnosis: How and Why Hypnosis Works.” http://www.homestead.com/selfhelpsolutions/hypnosis.html


Name: Ann Mitchell
Username: amitchel@haverford.edu
Subject: final paper
Date: Fri May 5 14:34:14 EDT 2000
Comments:
The Nature of Subjective States and the Question of How

Regardless of whether or not you are a scientist, on some basic level we are all, as humans, intrigued with the problem of subjective experience. The best example of this is that most humans spend their lives searching for someone to share their lives with; a person who we feel understands us best. Usually this person is someone who empathizes the most with our description of existence (or our subjective experience). In turn, this person will also describe their subjective experience in a manner strikingly similar to the way in which we ourselves (think we) conceptualize and describe our subjective experience. There is a need for a sense of shared reality that validates our existence as beings on earth. Some people like to call it a "connection." Yet, is the idea of shared reality a valid one? Is it really possible for others to experience exactly what another individual (human being or animal) experiences? What are the implications of the answer to this question?

In 1974, Thomas Nagel wrote an article entitled "What is it like to be a bat?" in which he explores the nature of subjective experience. Nagel begins his article by critiquing the idea of reductionism at the time. Reductionism, according to Webster’s College Dictionary, is "the theory that every complex phenomenon, especially in biology of psychology, can be explained by analyzing the simplest, most basic mechanisms that are in operation during the phenomenon." (p.1130) Nagel contends that models of reductionism do not help us understand the relationship between the mind and body. Furthermore, at present (1974) there is "no conception of what an explanation of the physical nature of the mental phenomenon would be."(p.435) That is, reductionist theories can not account for subjective experience.

Nagel defines subjective experience as what it is like to be an organism. He argues: "No matter how the form may vary, the fact that an organism has conscious experience at all means, basically, that there is something it is like to be that organism." (p.435) If the reductionst theory is true and existence(both mental and physical) can be explained in physical terms, the phenomenological features of experience of this physical existence must also be able to be explained in physical terms. The problem, as Nagel points out, is that the subjective character of experience renders a physical explanation impossible. Nagel’s main example is the problem of what it is like to be bat. Humans will never know what it is like to be a bat because we are limited to the subjective nature of our own experience. We can imagine ourselves to behave as a bat behaves, but imagination is also part of our subjective experience and therefore limited in its scope to help us understand what it is like to be a bat.

The crux of the paper is Nagel’s assertion that experience is irreducible when compared to other, reducible physical things, like lightning. Therefore, Nagel’s main objection to reductionism is that experience can not be reduced. The problem of physicalism, Nagel asserts, comes down to the problem of is/are in language. We can make the statement that mental states are physical states, but still not know HOW mental states are physical states. It is this problem of how mental states are physical states that limits human beings to their own subjective experience and not the experience of other beings. Nagel contends that: "We do not have the beginning of a conception of how it [physicalism] might be true." (p.440) He bases this statement on a distinction that he makes between a concept we think exists in theory but know we can’t comprehend and a concept we can’t even conceive of in theory and therefore don’t believe exists because our biological structure opposes the idea. "After all," Nagel reasons, "the nature of beings with access to humanly inaccessible facts is presumably itself a humanly inaccessible fact."(p.438)

At this point in the article, one wonders why Nagel didn’t entitle the paper On the State of Physcialism because he devotes so much of his discussion to whether or not it is possible for humans to really be able to conceive of a purely objective physical state. Nagel contends that, with experiences, there is no objective state. Rather, there exists a continuum from subjective to less subjective (or more objective), but the other end of the spectrum is not complete objectivism, which is the problem with reductionism or physicalism.

The debate about the question of how and the subjective experience has evolved since Nagel wrote his paper. Nagel wrote the article in response to the reductionist viewpoint at the time. Saul Kripke then made a similar argument in 1980 in an article entitled The Identity Thesis . In this article he argues that the identification of physical and mental states are different from that of temperature or gas molecules. Like Nagel he argues that subjective experience is irreducible in comparison to physical examples like lightning.

More recent philosophers have taken Nagel’s thesis in two different directions. In an article entitled "Can we solve the mind-body problem?" Colin McGinn argues fifteen years later in 1989 that we should never expect to have a concept of how the mind-body problem should be solved. He bases this idea on the limitation of cognitive structure (much like Nagel) much like quantum mechanics will forever elude monkeys. Four years later, in 1993, Joseph Levine wrote an article entitled On leaving out what it’s like in which he asserts that the explanatory gap(mind-body problem) will not remain forever for human beings because it is not an ontological (meaning relating to or being based upon existence) problem, but an epistemological problem(meaning the study or the theory of and around of knowledge, especially with reference to its limits and validity) for physicalism. He concludes that it is "possible to fill in the HOW of Nagel’s problem through causal elements." (p.30)

Our senior seminar class tried to brain storm some examples of the HOW question under the assumption that Nagel wrote the paper over 25 years ago, and surely some example has emerged in our modern world. Yet, the problem of the irreducibility of experience still proves to impede the possibility of any example that might answer the HOW question. In this context, we tried to explore the possibility of finding a physical model that, when looked at (or given a physical description) is known to have the property of having an experience. Nagel’s paper poses a major problem with the above proposed question because we couldn’t figure out how we were supposed to be able to tell if a refrigerator does or does not have a subjective experience just by looking at it. In this sense, how would we distinguish between knowing the subjective experience of a human versus knowing the subjective experience of a refrigerator? For now, I guess we’ll have to leave these questions up to the "experts", whomever they may be.

This paper explored several issues related to the subjective nature of experience using Thomas Nagel’s article "What is it like to be a bat?" The paper concedes that if our experiences are similar to one another it is possible that our experience is less subjective (knowing the quality of another’s experience). Yet, Angel’s argument still renders a complete connection or shared experience with someone impossible. This characteristic of subjective experience has interesting implications for our day to day experiences, as it seems to imply that in our subjective experience of existing, of being, we are alone. Further implications of this characteristic have implications for defining what is subjective or objective and the relationship of these definitions to the future of philosophy and biology.

References

Block et al. Eds. The Nature of Consciousness: Philosophical Debates, The MIT Press: Cambridge, MA, 1997.

Kripke, S. From Naming and Necessity, Lecture III (Cambridge: Havard University Press, 1980) 144-155.

Levine, J. "On Leaving out what it’s like." From, Consciousness, eds. M. Davies and G.Humphreys(Oxford: Blackwell, 1993) 121-136.

McGinn, C. "Can we solve the mind-body problem?" Mind, 98(891), 349-366, 1989.

Nagel, T. "What is it like to be a bat?" Philosophical Review, 83(4), 435-450. 1974.

Webster’s College Dictionary, Random House: New York, 1995.


Name: Feyza Sancar
Username: fsancar@brynmawr.edu
Subject: Biofeedback
Date: Fri May 5 16:49:42 EDT 2000
Comments:

Can we have conscious control over unconscious mechanisms?

Biofeedback: The new frontier of self-control

Biofeedback (BF) is a relatively recent development. The actual term "biofeedback" was coined in the last half of 1969 to describe certain laboratory procedures designed to train patients (or research subjects) to alter many autonomic or involuntary activities (1). Subjects were successfully trained to alter everything from brain activity, blood pressure, muscle tension, heart rate, and other bodily functions that are not normally considered to be under conscious control. The actual procedures involved in biofeedback training had been under development since the 1940's (1). Presently, biofeedback is used as a therapeutic tool. Biofeedback therapies have been proven efficacious in treating disorders ranging from the psychiatric, such as anxiety and mild depression, to headaches, chronic muscle tension, high blood pressure, and other debilitating physical states (2).

Methodologically speaking, biofeedback therapies utilize electronic or electromechanical instruments to accurately measure and feedback information about a person's neuromusculature and autonomic activities. The fed back information is normally in the form of binary, auditory, and or visual feedback signals, such as a flashing light or variable tone. By attending to these external cues, the subject forms an awareness of his or her internal state. Because the feedback cue is representative of the internal state, by altering the feedback cue the subject essentially succeeds in altering his or her internal state. Consequently, the information relayed by the 'feed back' cue has the capability of acquiring reinforcing properties. The reinforcing property of biofeedback is attributed to the high levels of self-efficacy experienced by the patient resulting from successfully 'changing' or altering their own physical state (2,4). This instills a feeling of success, achievement, and self-mastery in the trainee that serves as a positive reinforcer.

Given the definition and goal of biofeedback, it becomes clear that biofeedback implies the conscious control of unconscious functions, or, voluntary control over involuntary actions. Herein lies the scientific debate. Since the advent of biofeedback, a wealth of scientific research has been amassed addressing the mechanisms and validity of biofeedback. Many scientists have approached the essence of biofeedback, conscious control over involuntary behaviors, in an extremely skeptical manner. In fact, some previous research has shown biofeedback to be generally ineffective, especially in the context of brain wave alteration. In these particular studies, no physiological change was observed even after intensive biofeedback training (4). Those studies that did report alterations in physiology nonetheless contend that these alterations could not, due to some specified procedural confound, be considered a direct consequence of the subject's own volitional or conscious control. As it can be seen, the perceptions of biofeedback vary and hence the mechanisms of BF are thus far inconclusive.

In collectively viewing the literature, however, some general conceptual trends do emerge. Ultimately three main perceptions or 'schools of thought' on biofeedback can be identified. The first school posits that the mechanism underlying biofeedback is essentially a form of conditioning. Although involuntary functions of the autonomic nervous system can be conditioned using classical pavlovian procedures, biofeedback methodology falls under an operant conditioning paradigm. Operant conditioning involves the performance of a particular learned response in the expectation of reward. Here, the presentation of reward or reinforcement is contingent upon the performance of the specific response (a learned response). In this case, the learned behavior may be initially acquired by chance, but because the response was followed by a positive or reinforcing event, the 'successful' or rewarded response prevails while the unsuccessful response drops out. Operant conditioning is thought to possess a component of voluntary control since it is the goal directed, volitional, performance of some behavioral response, which directly results in the acquisition of reward. It is this acquisition of reward, which increases the likelihood of the specific response.

In the context of biofeedback, it is surmised that the individual learns, through the acquisition of a specific voluntary behavioral response, to control his or her visceral or autonomic functions. In this case, the response refers to the conscious alteration of an internal visceral state and is voluntarily performed with the expectation of a rewarding outcome. Furthermore, this rewarding outcome is contingent upon the successful performance of the required response. In a biofeedback situation in which a blinking light represents the individual's heart rate, the person learns to perform the voluntary behavior of decreasing the frequency of blinking. Of course, here, the decrease in frequency of the blinking would indicate a decrease in heart rate. Feedback indicating success, an actual decrease in heart rate as represented by an alteration in the feedback cue, instills a feeling of achievement, and self-mastery in the trainee that serves as a positive reinforcer. As a result of the conditioning procedure, the patient essentially learns to voluntarily control his or her visceral responses. (5)

As it can be seen, this interpretation of biofeedback supports the notion acquiring voluntary control over involuntary systems through an operant conditioning paradigm. Although this paradigm clearly implies a conscious element of control over functions that are under 'unconscious' control, there has been some protest over the assertion that there is direct link between conscious control and these unconscious mechanisms. Instead, it has been argued that perhaps the conscious control system may indirectly influence the involuntary visceral systems through the activation of some secondary mechanism. For example, it has been suggested that perhaps what is being consciously altered is a musculoskeletal function (which is, of course, under voluntary control) which in turn exerts an unconscious influence over an autonomic function. Take for example the control of intestinal motility. Perhaps conscious control is exerted over muscles surrounding the intestines that in turn subtly influences, and hence alters, the function or motility of the intestines.

The subtle, yet essential distinction here is the path through which conscious influence is exerted. The first argument is a proponent of direct conscious, or higher cortical control, over autonomic function:

CNS--Autonomic Function: conscious control of unconscious

The second argument is a proponent of indirect conscious or cortical control over autonomic function:

CNS--Peripheral nervous system/musculoskeletal activation--Autonomic Function: indirect conscious control of an unconscious function through the secondary activation of the peripheral nervous system.

One of the main sources of experimental evidence supporting the direct link between the conscious and unconscious systems are the observations collected from currarized animals. Curare is a substance which selectively paralyzes skeletal muscles. Curare functions by combining with the nicotinic cholinergic receptor on the post-synaptic membrane and thereby blocking competitively the action of acytylcholine (3). Hence, the skeletal muscle cells become effectively insensitive motor-nerve impulses, and thus fail to contract. However, because of the type of receptor and nature of the receptor blocking, smooth muscle function is left intact (3). Given this, the implementation of curare during biofeedback/operant conditioning selectively excises the confound of possible musculoskeletal intervention in the conscious control of visceral function.

In studies conducted by Miller and DiCara (1968 & 1967), curarized rats were instrumentally conditioned to control autonomic visceral responses (7,8). This conditioning paradigm involved the use of medial forbrain bundle (MFB, a 'pleasure' center) stimulation as reward. The presentation of this rewarding brain stimulation was contingent upon a specific response, which involved altering visceral/smooth muscle function (eg: increasing or decreasing heart rate or blood pressure). Every time an alteration in these visceral functions was detected, a duration of rewarding MFB stimulation was administered. The results of these studies collectively showed that increases in visceral activity such as heartrate or blood pressure were produced when alterations were rewarded by electrical stimulation of the MFB (7,8). Ultimately, the animal learned to perform the voluntary response of altering visceral function in order to receive rewarding stimulation (i.e. the behavior is performed with the expectation of reward). These findings imply that there may in fact be a direct influence of conscious, voluntary control over these visceral functions. Since the experimental animals in these experiments are functionally paralyzed, the results cannot be attributed to a secondary musculoskeletal mechanism which is under voluntary control. These findings are the most compelling to date that imply the potential to consciously or voluntarily control uncouscious functions.

Unfortunately, later studies conducted found it difficult to replicate the early findings showing control of heart rate. Furthermore, there have been studies involving the biofeedback training of brain waves that have prooven quite fruitless. These studies specifically involved the alteration of alpha brain waves using biofeedback. It had been observed that the enhancement of alpha brain waves using biofeedback techniques led to a 'quasi-meditational' state of consciousness characterized by relaxation, pleasantness, serenity, loss of body and time awareness, and an absence or diminution of thought (the 'alpha experience') (4). In these biofeedback 'alpha-enhancement' sessions, several studies have failed to find a significant occurrence of the of alpha experiences. Furthermore, when the alpha experience was observed as a result of biofeedback sessions, these studies uniformly failed to find significant correlations between the degree of alpha enhancement and the intesity or likelihood of alpha experiences. In this case, it was found that individauls would report the 'cognitive' or 'psychological' affects of the alpha experience in the absence of any significant physiological change in alpha rhythm strength. In a similar experiment using biofeedback training for the treatment of chronic tension headache, experimentors observed that improvements (50% decrement in the frequency of headaches) in the treated subjects were not correlated with in actual EMG (electromyograph) changes reflecting the amount of tension occuring within scalp muscles (6).

Instead, many investigators attributed the improvements and alterations in cognitive/psychological states to contextual variables intrinsic to the biofeedback setting. The contextual confounds of biofeedback setting include such elements as expectation and suggestion effects, as well as perceived success at the feedback task (resulting in increases in self-efficacy). Researchers concluded that in this instance, it is not an alteration in an endogenous physiological state that accounts for the changes observed, but the exogenous influence of contextual cues inherent in the biofeedback environment. These conclusions led to the second school of thought on biofeedback. In this case, biofeedback is considered as the ultimate placebo. Proponents of this theory contend that biofeedback mimics the placebo effect observed in clinical drug trials. Here, just as a person experiences a suggested psychological effect after injesting a "supposedly" psychoactive drug that is fact chemically innert, Biofeedback trainees may experience a suggested psychological effect during supposed psychoactive biofeedback training that in fact has no significant physiological effect. As such, although there are no physiological changes, the subject still report "experiencing" a certain change in their physical state.

Form this observation, researchers conclude that there is an obvious dichotomy at play. Physiology and experience are considered of distinctly different logical types (4). So, in essence, one can have an experience without physiological component, and one can have a physiological alteration without having a particular experience of this alteration. Form this perspective, physiological states are not equivalent to, or sufficient causes of, states of awareness, experiences, or behavior (4). From a neurobiological stand point, these conclusions seem completely counterintuitive. A wealth of information has been gathered in the field of neuroscience which is in direct opposition to the mind/body dichotomy presented in the biofeedback context. For instance, in the book "The Feeling of What Happens", by Antonio Damasio, a wealth of observations compiled clearly suggest that much of our cognitive state, specifically our conscious awareness, arrises from the 'mapping' of our physiological state from moment to moment (9). Furthermore, affective states are a direct consequence of the "experience" of a certain underlying physiological deviation (9).

It is, as such, virtually impossible to fully extricate physiology from the pscyhological experience and the psychological experience form the physiology. Furthermore, since these studies were only measuring changes across one variable (either brain waves or muscle tension) there is no telling what other physiological changes may have been occuring that were not being monitored and hence failed to be recognized. As such, it is extremely premature to assume that exogenous confounds of biofeedback such as resulting increments in self-efficacy and other contextual cues could alone account for the reported experience of an alpha state or the reported decrement in the frequency of headaches. At this point, it is extremely difficult to discount the possibility that a physiological correlate was at play and did contribute to the cognitive/psychological experiences reported by the subjects in these experiments.

Therefore, the clearest most logical explanation of biofeedback is presented by the third school of thought. This alternate view on the mechanism of biofeedback is conceptually similar to the instrumental-conditioning notion in that it conforms to the idea that one can in fact exert conscious control over unconscious mechanisms. However, this theory does away with most of the technical learning paradigms and deals with mainly the possible physiological and neurological transformations that may occur during the biofeedback process. Let us consider first that autonomic functions are governed by subcortical brain structures such as the brain stem, limbic nuclei, and hypothalamus (9). As these structures are constantly exerting control over autonomic functions, information regarding the changes in activity of the viscera is relayed between these subcortical control structures and the viscera via a feedback loop (9). The information relayed through this feedback loop is introceptive. Introceptive feedback refers to information from visceral afferents as well as humoral and chemical information related to these visceral functions. However, under general circumstances, higher cortical function and hence conscious awareness does not have any access to this introceptive feedback. The subcortical structures are 'in charge' and form a closed, unconscious, feedback loop with autonomic functions. In a sense, this stage is similar to an auto pilot situation since the regulation of autonomic function is completely reliant upon a self-regulating subcortical process and hence remains unconscious.

Under this general framework, the biofeedback procedure involves gradually becoming aware of the introceptive signals within the body. In this context, becoming 'aware' of the body's introceptive feedback essentially means gaining conscious access to the workings of the autonomic or visceral functions. This awareness is first provided through external sensory input as relayed by the electronic feedback cues that reflect the activity of some autonomic function. By being exposed to sensory input that represents information on the body's introceptive feedback, the conscious, cortical control mechanism gains access to the originally 'unconscious' feedback loop. As such, the conscious control center now acquires the ability to exert its influence over autonomic function by working through the subcortical brain structures (10). By exerting influence over subcortical mechanisms, the conscious control center thereby gains the opportunity to alter functions of the autonomic/visceral systems.

Through repeated exposure to the external sensory input of the feedback cue, the individual now becomes more sensitive to the changes occurring within their autonomic systems. Ultimately, the external sensory feedback cue becomes unnecessary since the conscious control mechanism, through training, can access the body's introceptive feedback through an internal functional pathway. In a sense, the information that was originally provided by an external sensory cue is now provided by an internalized sensing system brought about by the formation of a functional connection between the viscera and the conscious control center. As such, introceptive feedback is accessed internally by both subcotrical structures as well as conscious cortical mechanisms such that the unconscious closed loop now becomes a conscious open loop.

It is important to note that the conscious cortical control center described here is a very diffuse mechanism. It does not refer to one localized neural structure. One of the reasons why this neurobiological approach to biofeedback has attracted skepticism is because of the inability to pinpoint the exact origins of the cortical influence exerted on subcortical structures. However, this account is perhaps the most conceptually plausible explanation of the mechanism underlying biofeedback. The theory makes clear how physiological and neurobiological transformations occur during the biofeedback procedure to allow conscious control to be exerted over unconscious mechanisms.

The idea that one can have conscious access to unconscious functions redefines the meaning of self-control and expands the reaches of human potential. Perhaps the body is capable of healing itself without the use of exogenous chemical implements. The possibility of being able to attenuate a pathological imbalance within an unconscious autonomic system using the higher powers of conscious awareness is certainly an amazing feat. However, it does not seem so implausible when one considers those involuntary functions that are constantly being trained using conscious awareness. Take for example toilet training. Bladder control is mediated by involuntary functions (smooth muscles are involved). However, children every day are taught to 'control' this autonomic function. What is it that is going on here? Bladder control is originally under involuntary control, no doubt. So, by being toilet trained, a child ultimately learns to exert conscious control over the involuntary action of the smooth muscles of the bladder. Given this common instance of conscious control over an involuntary function, it should not be too difficult to accept the potential of human consciousness. With every such account of self-healing or self-training, the mechanism underlying biofeedback described above becomes more plausible even to the point of being common place.

References:

1) AAPB Website: Public Information Area. "What is Biofeedback?" http://www.aapb.org/AAPBpbiofeedback.html

2) Wall, Stephen E. (1997) "An Overview of Biofeedback" http://www.7hz.com/1overview.html

3) Goodman and Gilman's The pharmacological Basis of Therapeutics. Gilman, Ralls, Nies, Taylor, Ed. New York: Pergamon Press, 1990.

4) Plotkin, William B. (1979). "The Alpha Experience Revisited: Biofeedback in the Transformation of Psychological State" Psychological Bulletin, Vol.86(5):1132-1148.

5) Mazure, James E. Learning and Behavior: Fourth Edition. New Jersey: Prentice Hall, 1998.

6) Rokicki, L.A., Holyroyd, K.A., France, C.R., Lipchick, G.L., et al. (1997). "Change mechanisms associated with combined relaxation/EMG biofeedback training for chronic tension headache" Applied Psychophysiology and Biofeedback, Vol.22(1):21-41.

7) Miller, N.C., DiCara, L.V., Banuazizi, A. (1968). "Instrumental learning of glandular and visceral responses" Conditional Reflex, Vol.3(2):129.

8) Miller, N.C., DiCara, L.V. (1967). "Instrumental learning of heart rate changes in curarized rats: Shaping and specificity to discriminative stimulus" Journal of Comparative and Physiological Psychology, Vol.63(1):12-19.

9) Damasio, Antonio. The Feeling of What Happens: Body and Emotion in the Making of Consciousness. New York: Harcort Brace and Company, 1999.

10) Norris, Patricia (1986). "Biofeedback, voluntary control, and human potential" Biofeedback and Self-Regulation, Vol.11(1):1-20.


Name: Nicole Stevenson
Username: nstevens@brynmawr.edu
Subject: locked-in syndrome
Date: Fri May 5 19:15:51 EDT 2000
Comments:

Locked-In Syndrome

Imagine being fully aware of your surroundings and unable to communicate or move a muscle. Locked-in syndrome is described as one of the cruelest medical problems to date. People who suffer from locked-in syndrome are prisoners in their own bodies, some who make varied recoveries but many who never regain any semblance of their former life. This syndrome is a global insult upon the body, patients are literally locked-in their bodies, unable to move. The implications of this disorder are very vague and expansive at the same time, quite confusing to the medical community.

Locked-in syndrome is a rare neurological state in which the brain stem is damaged due to a vascular accident, trauma, or tumor. Diseases such as Parkinson’s, Lou Gehrig’s and Huntingtin’s disease, strokes, and pneumococcal meningitis have all strangely been present when patients have become "locked-in". This state of mind and being does not seem to have a clear etiology. The brain stem is the essential communication center between the brain and the body. Damage to the anterior region of the brain stem, the section responsible for almost all of the motor signal pathways of the body, results in locked-in syndrome. Damage to the posterior region of the brain stem results in a coma or persistent vegetative state, essentially brain death. The difference between the two very different types of damage is mere millimeters. Comatose state usually results from damage to the upper midbrain, hypothalamus, and in some instances, the thalamus. According to neurologist Damasio, these structures are required to implement the protoself, or of consciousness, which allows the individual the image of self. He supports claims that anterior brain stem damage does not damage one’s state of consciousness. The motor pathways concerning blinking and vertical eye movement are the only ones located in the back of the brain stem, thus usually allowing locked in patients a means of communication with the outside world. The initiation of voluntary movement is incapacitated by this disorder as the damage blocks the message transmission path. The necessary electrical impulses from various brain cells needed to trigger the release of chemical messengers along the neuronal pathways are muted. Almost all of the muscles within the body fail to receive the needed signals to control the muscles to act and react. The cessation of necessary signals along the motor pathway occurs in the ventral pons and disconnects the motor cells in the lower brain stem and spinal cord. This causes a varied range of issues, generally resulting in the quadriplegia, lower cranial nerve paralysis, and mutism.

Despite the virtual solitary confinement of the sufferer’s mind, they continue to have a sense of themselves and the world surrounding them. Patients suffering from locked-in syndrome mimic those in a coma but unlike coma victims, they demonstrate "alert wakefulness" and are able to receive and conceive sensory stimuli. Researchers and physicians believe that while it has been altered, consciousness in locked-in victims is preserved and functioning. However, it has been found that as the extent of the damage to the brain stem varies, so does the purity of the state of consciousness. Full alertness is found in some patients, while other seem to zone in and out of wakefulness. Some people seem to be the same, simply trapped within their motionless bodies, while others change drastically. One thing remains constant, they are alive and awake on the inside, mentally and consciously functioning in a way uncommon to most neurologically challenged patients.

Plum and Posner are the two of the leading neurologists in the study of consciousness of locked-in patients. They are attempting to identify the parts of the brain responsible for consciousness and what trauma does or does not result in this devastating condition. EEG reactivity has been discarded as competent test for consciousness as it is present in some patients and not in others. Somatosensory evoked potentials also varied from unilaterally normal to bilaterally absent. MRI scans also reveal varying damage to differing sections of the brain, besides the standard anterior brain stem injury. Difficulties in identifying what is responsible for consciousness is also present due to the fact that so many varying conditions have resulted in patients becoming trapped within their minds. Many patients have suffered a stroke or various other conditions which cause them to loose consciousness, wake up "locked-in". Yet somehow these patients seem not to suffer as much as one would think. They are awake and alert of their surroundings and mental functioning yet seem to slip into an inward state of calm and tranquility. They report feelings of sadness and frustration in relation to their new condition yet no panic, fury, nor extreme negative feelings are exhibited. Damasio considers the brain stem the beginning of the "body loop" mechanism, which is responsible for emotions. He states that electrical signals, which are conveyed through the neuronal pathways, are responsible for the existence and regulation of this mechanism. When damage occurs to the brain stem is alters the structure’s ability to convey messages, thus causing a breakdown in feelings and expression of emotions. The brain is still able to activate emotion induction sites within the hypothalamus and basal forebrain, but these emotions are quite different from the ones experienced when the patient was healthy and free of brain damage. Damasio hypothesizes that the background internal state of the body is intact and seemingly takes over the emotional state of the individual, resulting in a more calm, peaceful state of mind. He explains the lack of suffering from the debilitating condition as a result of lack of emotional flow. Reports of the research and use of curare support Damasio’s ideas, a drug used to block muscular activity during surgery. Blocking the nicotinic receptors of acetylcholine activates artificial paralyzation. These receptors are responsible for regulating and activating the neuronal messages, which control the movement of muscles. Patients who report experiencing the effects of curare before the anesthesia, which is responsible for disengaging consciousness and putting the patient to "sleep", recount feelings of panic and worry along with the ability to hear, see, and grasp all that is going on around them and to them, absent only of actual physical feeling. These are the feelings one would think are present in locked-in patients. Nonetheless, it has been found that muscarinic, not nicotinic receptors are responsible for the neuronal messages that are involved in the autonomic control of emotions. Therefore voluntary emotions are not effected by the paralyzing curare, reinforcing Damasio’s idea of the "body loop" mechanism and the muting of emotions in locked-in patients.

There is much controversy and conflict over the causes and exact implications of this incapacitating neurological condition. Physicians are on both sides of the fence concerning care for and opinions on the mental and physical states of these patients. Some patients have exhibited what seems like pure luck, able to successfully experience varying forms of rehabilitation and recovery, while other remain stuck forever within the immobile bodies which house their functioning minds. Continued research is imperative to more fully grasp this condition and more successful treatment options.

References

Damasio, A. (1999) The Feeling of What Happens: Body and Emotion in the Making of Consciousness. Harcourt, Brace & Co., New York

Haig, A.J., Ho, K.C., & Ludwig, G. (1996) Clinical, physiologic, and pathologic evidence for vagus dysfunction in a case of traumatic brain injury. Journal of Trauma, vol. 40

Gutling, E., Isenmann, S., & Wichmann, W. (1996) Electrophysiology in the locked-in syndrome. Neurology, vol. 46

http://www.strokenetwork.org/brainstem

http://www.sfn.org/briefings/locked-in.htm

http://www.club-internet.fr/alis/maingb.html

http://ets.uidaho.edu/med532/Locked_in.htm


Name: Ruchi Rohatgi
Username: rrohatgi@brynmawr.edu
Subject: Prosopagnosia
Date: Fri May 5 22:26:37 EDT 2000
Comments:
In 1947, Bodamer first termed prosopagnosia to describe the inability to recognize familiar faces (Ellis, 1990). Within prosopagnosia, there are varying levels of severity- some patients are able to match faces normally, others have impairments that extends into recognition of specific objects such as cars, types of tree, etc. In some cases, the impairment is so severe that the patient is unable to recognize his own face in a mirror. Prosopagnosic patients remain able to recognize familiar people by voice, gait, or distinguishing features, and can correctly describe a person if presented with their names.It is essentially not the knowledge about familiar people that is lost- it is only access to this knowledge when presented with a face that is impossible. Work by Meadows (1974) has shown that patients with prosopagnosia nearly always have a left upper quadrant visual field defect associated with a right occipitotemporal lesion. Also, a symmetrically placed smaller left-sided lesion is associated with this disorder (Heilman, p.198).

Covert face recognition- the ability to indirectly recognize faces such as by physiological responses, but not directly recognize faces such as by overt recognition- is a characteristic displayed in some prosopagnosics. Schweinberger, Klos and Sommer investigated covert face recognition in a patient with prosopagnosia. This patient performed well in various face processing tasks such as expression analysis (reading emotions), feature processing and had relatively preserved semantic knowledge about persons, but was impaired in the visual matching of unfamiliar faces. While prosopagnosic patients will not recognize people by their faces, covert knowledge for overtly unrecognized faces can be demonstrated. Early experiments testing the covert recognition attributes used a classical conditioning procedure. Presentations of a patients own face but not other faces were paired with brief electric shocks. It was shown that the patients seemed to have developed differential autonomic responses contingent on his own face. In 1991, Bruyer and his colleagues found that patients could learn to better associate familiar faces with correct names that with false names. They concluded that face identity, although not overtly recognizable, continued to influence behavior. Furthermore, psychophysiological studies have provided evidence for covert recognition in prosopagnosics. In 1984, Bauer studied electrodermal responses in prosopagnosic patients by pairing familiar faces with either correct names or incorrect names. He found that the electrodermal (EDR) responses were larger for correct names rather than for incorrect ones. In 1982 Damasio found that patients' visual scanning behavior was actually different for familiar faces rather than for unfamiliar faces. He also observed larger EDR's for familiar as opposed to unfamiliar faces.

In light of studies performed for covert recognition, there are two school of thought based on the way prosopagnosia exerts its effects. One group believes that there are independent brain systems for overt and covert face recognition. The other group believes that there is one system in which there is a disattachment from consciousness centers. Bauer, a proponent of the former view believes that EDR discrimination associated in covert recognition is based on a dorsal visual-limbic pathway, whereas damage of the ventral occipitemporal projections is held responsible for overt face recognition deficits (as seen in prosopagnosia). This model of independent brain systems for overt and covert face recognition implies that performance in overt and covert tests may be completely independent of each other. Farah and her colleagues believe that prosopagnosia involves an impairment in the processing of faces, although to varying degrees depending on the severity of the disorder. The also believe that the cover recognition seen in these patients is based on the residual information encoded in a damaged visual recognition system. So although Farah's group does not go so far as to say that there is a separate covert recognition "entity" in the brain, they put emphasis on the existence of a separate overt system related to the visual processing center.

The latter view is supported by Dehaan et al. This group suggests that covert face recognition might be brought about by a single normally functioning face recognition system which is however, disconnected from a "conscious awareness system" necessary for overt recognition. A study by Mcneil and Warrington may also support this case. Their research was based on a man who became a sheep farmer after a stroke. He learnt to recognize and name many of his sheep, and his performance on tests of recognition memory and paired- associate learning for sheep was significantly better than on comparable tests using human face stimuli. In this case, this farmer can perform recognition memory tasks involving visually difficult stimuli other than faces. So his prosopagnosia can be viewed as an associative deficit. The strategies he was thought to have employed to recognize sheep was developing a sheep prototype which enabled him to effectively encode sheep facial features. It is surprising that he can even generalize this system to other visually dissimilar breeds of sheep. However, he was not able to utilize these types of strategies for other visual stimuli (such as for faces). This suggests that his damaged face recognition system is actually still operating to such an extent that it prevents him from developing new strategies for use with faces. The researches proposed that the problem in this case lies in the dissociation from output from face recognition units to person identity nodes. The face recognition, they believe, are not damaged but are in essence disconnected from the person identity nodes (these nodes are present in the reflexive attributes of a person, i.e., how they relate back to someone and how someone affects that person). So intact face recognition units may prevent the development of alternati1ve methods of perceptual encoding.

This semester in senior seminar we read The Feeling of What Happens, by Antonio Damasio. It is interesting to look at his views of prosopagnosia and to compare them with others on this disorder. Damasio puts prosopagnosia in the disorders of the "something to be known category", which is comprised of two types: 1) perceptual disorders (such as being blind or deaf) in which the proto-self is not changed and thus core consciousness does not ensue, and 2) agnosias which are the inability to conjure up from memory the sort of knowledge that is pertinent to a given object as the object is being perceived. In the case of prosopagnosia, the second group is more applicable. In this case, there are breakdowns in the visual sensory modalities that ultimately affect extended consciousness.

Damasio tells us about a woman named Emily who could not recognize visual stimuli such as familiar faces, a particular house, etc.. However, non- visual aspects of the same stimulus, sound or touch, brought to mind what she needed in order to know. Damasio believes that Emily's core consciousness is not affected (unlike in the perceptual disorders category). He states that she is conscious of what she knows and what she does not know. This leads one to question what in fact is affected, if core consciousness is not. Damasio comments that her problem is one of memory. If this is in fact true, then one may attribute prosopagnosia as a breakdown in the extended consciousness realm. Extended consciousness is a consequence of 1) the ability to learn and retain records of various experiences; and 2) the ability to reactivate those records in such a way that as objects, they, too, can generate a "sense of self knowing." Since Emily cannot learn and associate faces generated by visual stimulus, her autobiographical self is also affected. Therefore, she cannot form the associative property- the property that relates these stored experiences back to herself. She therefore relies on other types of memories, such as the way someone walk, or talks or dresses to remember. The instant that a prosopagnosic patient sees a face, she cannot recognize the face, but she can sense that she really does not know who it is (therefore her core consciousness is no affected). But once she hears the person's voice, another memory system may be triggered and acts as an input to the face recognition unit. However, there is a dissociation in the face recognition sphere and the subsequent extended consciousness unit that allows her to attribute the information back to herself and allows her to recall. Physiological responses (such as EDR) associated with covert recognition can be explained in Damasio's terms as being associated with emotions. This is below the extended consciousness realm and is thus not affected in these individuals.

Prosopagnosia can also be explained by another scheme put forth by a researcher named Ned Block, a linguistics and philosophy professor at MIT. He wrote an article called "On confusion about a function of consciousness" where he states that there are a number of very different "consciousnesses". He calls one Phenomenal consciousness (p-consciousness), which is the experience of a state as in "what it is like to be in that state." He calls the second type Access-consciousness (a-consciousness) which is available for use in reasoning and rationally guiding speech and action. For instance, P-consciousness includes the experiential properties of sensations, feelings, and perceptions. It is often representational and also includes desires, and emotions. A-consciousness is a readily available premise in reasoning, poised for rational control of action (and rational control of action.). These two types are different are also interrelated.

The Schacter model of consciousness is based on the idea of a-consciousness and p-consciousness. In this view, a-consciousness is present when what is represented by the perceptual state is processed through a higher order information-processing system (called the Executive system) whereby it is then used to control the reasoning and behavior (a-consciousness).

There is evidence that primate visual systems have distinct dorsal and ventral subsystems- much of the info in the ventral system is much more closely connected to P-consciousness than that in the dorsal system. If there is damage to dorsal systems, other subsystems may not have enough machinery for reasoning or reporting rational control of action to allow their P-conscious states to be A-conscious. Examples of having P-consciousness without A- consciousness includes the following: you are engaged in intense conversation with someone when suddenly, at say noon, you realize that right outside your window there is- and has been for some time- a deafening drill digging up the street. You were aware of the noise all along, but only at noon are you consciously aware of it. So, you were both P conscious of the noise all along, but at noon you are both P and A conscious of it. At noon you get higher-order thought as well as A-consciousness. In the first scenario, the belief that is acquired at noon is that there is and has been a noise, and in the second scenario, the beliefs that are acquired are the first one plus the belief that you are and have been experiencing the noise. A-consciousness without P-consciousness are not extensively documented, but one could think of a robots that "think" but do not necessarily "feel" in the way that we may are accustomed to.

Both Damasio and Block's theory of consciousness in terms of prosopagnosia revealed a dissociation between various inputs (including some memories, visual input, etc.) and higher order processing. In Damasio, there is a dissociation with higher processing units (extended consciousness) and in Block's theory, there is a breakdown between P- consciousness and A-consciousness (via the higher order Executive System).

References:

1) Block, Ned (1995). On Confusion About a Function of Consciousness. Behavioral and Brain Sciences. 18:227-87.

2) Bruyer, Raymond (1991). Covert Face Recognition in Prosopagnosia: A Review. Brain and Cognition. Vol. 15,2:223-27.

3) Damasio, Antonio, H. Damasio and G.W. Van Hoesen (1982). Prosopagnosia: Anatomical Basis and Behavioral Mechanism. Neurology. 32:321-41.

4) Damasio, Antonio. The Feeling of What Happens, Body and Emotion in the Making of Conciousness. New York: Harcourt Brace & Company. 1999.

5) De Haan, E.H.F., R. Campbell (1991). A Fifteen Year Follow-up of a Case of Development Prosopagnosia. Cortex. 27,4: 489-510.

6) Ellis, H.D., M. Florence (1990). Bodamer's (1947) Paper on Prosopagnosia. Cognitive Neuropsychology. 7,2:1-81.

7) Heilman, K.M., E.Valenstein. Clinical Neuropsychology. New York: Oxford University Press, 1979.

8) McNeil, J.E., E. Warrington (1993). Prosopagnosia: A Face Specific Disorder. The Quarterly Journal of Experimental Psychology. 46A:1-10.


Name: Melissa
Username: mwachter@haverford.edu
Subject:
Date: Sat May 6 00:02:34 EDT 2000
Comments:
Melissa Wachterman

Can Animals Suffer?

Consciousness is a topic that has for centuries been, and continues to be, explored by a wide range of academics from philosophers to neurobiologists. The theories that are thrown around in these academic circles, while they may at times seem to be mere intellectual banter, have a wide spectrum of moral and ethical implications. This paper will focus on ethical issues related to animal rights and the ramifications that our philosophical and neurobiological concepts of suffering and pain have in regard to this topic. I write this with the hope that it will be a jumping off point for future examinations of many other socially relevant issues related to consciousness through a lens that integrates both philosophical and neurobiological perspectives. I maintain that such an integration will inform our ethical thinking and decision-making in a way that neither perspective alone could do.

I think that it is fair to say, based on my readings, that most animal rights activists are driven primarily by a commitment to decreasing the suffering of animals. For example, according to Donald Graft, "It is [animals’] alleged capacity for suffering that motivates animal rights activists to seek to extend the circle of compassion to non-human animals" (Graft, web source). Yet, inherent in this line of thinking is the assumption that all animals are capable of suffering, and there is reason to critically examine this presumption from a neurobiological perspective. Since meaningful linguistic communication with animals is not possible, our concepts of the existence and nature of animals’ internal states are generally based exclusively upon their external behaviors. When it comes to evaluating suffering, those who adhere to an animal-right’s philosophy maintain that overt pain behaviors are indicative of suffering. This is reflected in a lot of their writing in which they often use the terms "pain" and "suffering" interchangeably, as if they are synonyms. Yet, there is research that reveals that from a neurobiological perspective, the existence of pain sensation and many of the associated pain behaviors is distinct from the experience of pain, which is, presumably, a prerequisite for suffering. There is contemporary philosophical grounding for the ethical stance against the use of animals for experimental research, the food industry, or a wide range of other purposes. The philosophical basis of the animal rights movement, in many respects, grows out of the utilitarian tradition and the work of Peter Singer, who builds his theories largely upon ideas put forth by 18th century English philosopher Jeremy Bentham (Best, 2000, web source). Utilitarianism maintains that the best deed is that which brings the greatest amount of pleasure to the greatest number of people. Singer is often cited as the world’s leading proponent of this utilitarian perspective (though he clearly would take issue with the final prepositional clause in the preceding sentence). In his book Animal Liberation, Singer reasons that the ability of animals to feel pain and pleasure means that they belong on a plane of moral equivalence with humans (Singer, 1990a). In an excerpt from this book, Singer quotes Bentham’s view that in considering the moral standing of animals, "The question is not, Can they reason? nor Can they talk ?, but, Can they suffer ?" (Singer, 1990b, p 23). Reflecting on this quote, Singer agrees with Bentham that the capacity for suffering is the crucial characteristic that grants a being the right to equal consideration. He argues that the ability to suffer is a much less arbitrary place to draw the line between those that do and do not have interests that need to be taken into account than the ability to reason or use language. After all, he argues, the ability to suffer and enjoy is a prerequisite for possessing interests at all. According to Singer, the capacity for suffering and enjoyment is not only necessary, but also sufficient for it to be established that a being has interests (Singer, 1990b). Singer, himself writes, "If a being is not capable of suffering, or of experiencing enjoyment or happiness, there is nothing to be taken into account. So the limit of...capacity to suffer...is the only defensible boundary of concern for the interests of others" (Singer, 1990b).

With that established, the central issue that now inevitably arises is how to determine if animals are capable of suffering. In an article entitled "Do Animals Feel Pain?", Singer moves outside of the realm of philosophy to make some arguments to support his belief that this question should be answered in the affirmative. Yet, in doing so, he makes some assertions that can be challenged from a neurobiological perspective. In fact, the entire premise that if one can establish that animals feel pain, then it is a given that they can experience pain and suffer is potentially flawed, as we will see when we examine the work of Demasio in the second half of this paper. Within the article, Singer points out that almost all of the external signs of pain seen in humans are seen in animals, including behavioral signs such as writhing and moaning. In addition, animals manifest similar physiological responses, such as dilated pupils and perspiration, under circumstances in which we know we would experience pain. He takes this as evidence that animals must be experiencing pain as well (Singer, 1990c, web source). However this assumption is problematic because, as will be discussed further, the brain is certainly capable of sending out motor messages to the body, based on sensory pain input, without involving the "I" function at all (Grobstein, Biology 202, 2000). He then goes on to make an evolutionary argument that animals must be able to feel pain because an ability to do so is evolutionarily advantageous as it leads members of a species to stay away from sources of injury (Singer, 1990c, web source). This is a big jump because while it certainly is evolutionarily adaptive to be able to respond to pain by performing a behavior that enables you to avoid the injurious source, a conscious experience of the pain is not necessary in order to initiate such a behavior.

Philosophers such as Singer throw terms like "suffering" around without any concrete notion of how to critically evaluate its existence, which can leave those who have more of a scientific bent, a bit unsettled. The work of Marion Stamp Dawkins, who studies animal behavior at Somerville College, Oxford, is more quantitative in defining suffering and proposing experimental procedures that, in theory, could be used to examine suffering. Yet, as we will see, there are problematic aspects of her approach, which relies heavily upon behavioral output as indications of suffering, a measure that may not be valid. Dawkins asserts that there are two main strands that are discernible from the "bowl of spaghetti-like reasoning" that we utilize as the ethical bases for our treatment of animals: in general, we value animals which appear clever or which demonstrate proof of the ability to reason and we value organisms which show evidence of the capacity to suffer and to feel pain (Gribble, web source). Dawkins defines suffering as states in which an animal would prefer not to be and from which it would most likely try to flee if it had the chance. Aware that animals do not have the means to inform humans of their states of suffering through language, she offers three alternate sources of evidence: the overall state of health of an animal (for example, squealing, struggling, convulsions), physiological states (for example, increased heart rate, brain activity, hormone levels) and manifest behavior (Dawkins, web source). Dawkins refers to a 1978 experiment reported by A.P. Silverman in Animal Behavior as an example of behavioral evidence of an animal being in a state of suffering. Rats were put into air-tight containers and exposed to tobacco smoke. Over time (she does not indicate how long), the rats learned to stop up the smoke-vents with their own feces, thereby expressing, in Dawkins view, "what they thought of what was being done to them" (Dawkins, web source). Dawkins goes on to propose experimental procedures that she believes could be implemented in order to figure out the degree to which an animal is suffering within a particular state. The main experimental evidence of suffering in her model is behavior that demonstrates that the animal is "working hard", defined as expending energy or sacrificing food, to try to escape (Dawkins, web source).

The problem with Dawkins approach is that it relies on the idea that there is a strict correspondence between how one behaves and how one feels. Throughout this paper, I have alluded to the idea that there is neurobiological evidence for a dissociation both between pain behaviors and the experience of pain and between the experience of pain and suffering. I now aim to set forth the evidence to support this claim. To do so, I turn to the work of Antonio Demasio, in his book The Feeling of What Happens. Recall that both Singer and Dawkins point to external behavioral signs of pain (e.g. writhing) and physiological changes (e.g. increased heart rate) as signs of suffering in animals. After all, they reason, we know that when those changes manifest themselves in us, they are almost always accompanied by the experience of pain and suffering. Yet, as Demasio eloquently points out in his book, pain and the experience of pain are by no means universally equatable phenomenon. Since only in the latter case is there even the potential for suffering, the distinction is meaningful in this discussion, and therefore, should be further explored. The way that I conceptualize it, there is a progression along a spectrum beginning with the physical sensation of pain (often referred to as nociception in order to distinguish it from the more colloquial use of the word "pain"), extending to the experience of pain, and then at the far end of the spectrum is suffering, which, as we will see, can be distinguished from the experience of pain.

Demasio points out that if one’s hand were placed on top of a hot stove while the brain was in an unconscious state, the self-less brain would nonetheless receive nociceptive (pain) neural patterns produced as a result of tissue damage, and would generate a series of behavioral responses. In addition to the withdrawal of the arm from the stove, other emotional responses would automatically occur as well, including alterations in facial expression and variations in heart rate. The point is that while all of these behaviors in response to pain take place in conscious human beings, consciousness is not a prerequisite for the responses to occur (Demasio, 1999). This reveals the problematic nature of Dawkin’s use of behavioral measures as indications of an animal’s capacity to suffer. While it is true that the physical sensation of pain can be observed from overt behavior, it should now begin to become clear that to count behavior as absolute evidence of experiencing pain, much less suffering, is not valid.

In a more general sense, there is evidence for a dissociation between how one behaves and what one is capable of feeling/experiencing. Two clinical conditions, namely locked-in syndrome and blindsight, offer clear proof of this dissociation. A person who has locked-in syndrome has an intact consciousness (i.e. they are awake, alert, and conscious of their mental activity), yet cannot move any muscle in their entire body, and thus cannot perform any behavior, save the vertical movement of the eyes. The condition results from anterior lesions to the pons or the midbrain, and illustrates the ability to experience but not behave (Demasio, 1999). On the other hand, a person who manifests a condition known as blind-sightedness, completely denies the experience of seeing anything, yet, when asked to guess the possible location of an object, will point in the correct direction with a frequency well above chance. In this case, the person is able to exhibit behaviors in the absence of having any visual experience (Demasio, 1999).

Having laid out evidence for the dissociation between how one behaves and how one feels, both in the context of pain and on a broader scale, we now move to a comparison between the experience of pain and suffering. As we will see, one can have an experience and awareness of pain, completely devoid of suffering.

Throughout his book, Demasio relates the stories of a number of his patients, most of whom have brain lesions that reveal something about the nature of issues related to consciousness. A relevant example for the present purposes concerns a man who suffered from a debilitating case of refractory trigeminal neuralgia in which even the lightest touch of the skin or face would provoke an agonizing pain. Having found all known pain medications to be ineffective, the poor man is said to have spent his days hunched in the corner, immobilized by his condition. As a last resort, surgery was performed in which small lesions in a specific part of the frontal lobe were made. Demasio recalls that when asked about the pain two days after the operation, the patient reported that "the pains were the same", but that he felt fine now. From a neurobiological perspective, nothing had been done to alter the sensory input patterns signaling local tissue dysfunction coming in from the trigeminal system. Furthermore, because the mental images of the tissue dysfunction were not changed, the patient still had the awareness and experience of pain. And yet, while he was still experiencing the pain, as a result of lesioning the frontal lobe, the suffering was completely gone (Demasio, 1999). One might take this case study as evidence that it is the frontal lobe that mediates organisms’ capacity to suffer, which would lead to the conclusion that any organism that does not have a highly developed frontal lobe is incapable of suffering. However, I would find any such argument to be overly simplistic and misguided from the neurobiological perspective. Clearly, different organisms’ brains have developed under different environmental pressures, and therefore, it is possible that regions of the brain other than the frontal lobe can mediate suffering in non-human animals. Rather, I use this case study as an illustration of the dissociation between the experience of pain and suffering.

Another problem with the experimental criterion that Dawkins proposes as evidence of suffering is that it seems that they could be satisfied by an artificial being. Recall that the standard that Dawkins puts forth is based in an organism’s ability to behaviorally demonstrate that it is working hard to try to get out of a situation that it would rather not be in (Dawkins, web source). As Paul Gribble point out, it seems that it would be entirely possible for a mobile floor-sweeping robot constructed out of heat-sensitive material to "suffer" under this definition of the concept. Imagine that in addition to heat sensors, the robot is equipped with crumple-detectors, so that when its outer layer begins to crumple from any form of impact, it will reverse the direction of its movement. Say that a student lured this robot into a room by dropping a trail of cookie crumbs, and then locked the door and turned up the heat. When the robot’s heat sensors begin to detect heat levels significantly above its pre-programmed thresholds, the robot will begin to move around the room, only to discover that its detectors register excessive heat levels throughout the room and the door is locked. Since the robot has been programmed to consider heat regulation as its top priority, it will roll itself to the back of the room, and then throw itself forward into the door, ignoring the warning messages from its crumple-detectors. In the scenario described, it is evident that the robot is in a state in which it would prefer not to be and is working hard to escape the situation, even at the expense of possibly severe structural damage. Therefore, it satisfies Dawkins criterion for suffering, and its interests have been revealed. Thus, according to Singer, we are now morally obliged to consider its interests. Clearly this conclusion is incredibly disturbing, and therefore, we are strongly inclined to want to modify the criteria used to determine suffering in a way that eliminates artificial beings. Yet, when we consider doing so, we quickly realize that we are, in a sense, trapped. In an effort to make these criterion stricter, we would need to utilize more internal or subjective measures than the external, objective behavioral standards suggested by Dawkins (Gribble, web source). But any move in such a direction will come under attack by Thomas Nagel, who argues that it is impossible for a human to envision what it is like to be another organism (or an artificial being for that matter), precisely because a human is not that organism or being (Nagel, 1981).

So where does all of this leave us in terms of gaining insight into whether animals are capable of suffering? We are, in many ways, left in a very tough bind. As this paper has revealed, there is, from a neurobiological point of view, a great deal of uncertainty inherent in approaches that attempt to infer the experience of feelings, much less suffering from external behavior. In addition, there is valid concern that theories of suffering that rely solely upon behavioral measures are inadequate because, as demonstrated, artificial beings can meet the behavioral criteria for suffering, though they experience nothing. Nagel strongly cautions us against getting any idea in our mind that we would be able understand the subjective experience of other organisms. Nagel uses the bat as an example in his writing. According to Nagel, even the best, most informed attempt on my part to imagine being a bat would yield only a sense of what it would be like for me if I were a bat. And that is not what is at issue; rather our concern is with what it is like for a bat to be a bat, and whether, as a bat, a bat is capable of suffering (Nagel, 1981).

So, after an exhaustive examination of the issue, it seems clear that, at least at this point, it is not possible to show when suffering occurs. My sense is that with time, as more and more is discovered about the brains of humans and other organisms, we may develop better ways to assess whether animals are suffering. Yet, even under the best of circumstances, this judgment will never be perfect. Therefore, as far as the ethical issue stands, the question really comes down to a decision about how willing we are to lean over backwards in order to avoid the unfounded, but irrefutable possibility of potentially causing suffering in animals.

Works Cited:

Best, Peter. "Life and Death Ethics: The Passion and Paradoxes of Peter Singer". http://www.britannica.com/bcom/original/article/0,5744,3576,00.html

Damasio, Antonio. The Feeling of What Happens–Body and Emotion in the Making of Consciousness.. New York: Harcourt Brace & Company, 1999.

Dawkins, Marian Stamp. "The Scientific Basis for Assessing Suffering in Animals". http://www.animalconcerns.org/ar-voices/assess.html

Graft, David. "Animal Suffering". http://www.animalconcerns.org/ar- voices/anim_suffering.html

Gribble, Paul. "Cognitive Science and Animal Rights". http://www.etext.org/Zines/Intl_Teletimes/Teletimes_HTML/cognitive_science.htm

Grobstein, Paul. "Biology 202: Neurobiology and Behavior", Bryn Mawr College, Spring 2000.

Singer, Peter. Animal Liberation. New York: Avon Books, 1990.

Singer, Peter, "All Animals are Equal" in Harnack, Andrew (Ed.), Animal Rights, Opposing Viewpoints, San Diego: Opposing Viewpoints Series, 1996.

Singer, Peter. "Do Animals Feel Pain?". http://arrs.envirolink.org/ar-voices/pain.html


Name: Melissa
Username: mwachter@haverford.edu
Subject:
Date: Sat May 6 00:02:38 EDT 2000
Comments:
Melissa Wachterman

Can Animals Suffer?

Consciousness is a topic that has for centuries been, and continues to be, explored by a wide range of academics from philosophers to neurobiologists. The theories that are thrown around in these academic circles, while they may at times seem to be mere intellectual banter, have a wide spectrum of moral and ethical implications. This paper will focus on ethical issues related to animal rights and the ramifications that our philosophical and neurobiological concepts of suffering and pain have in regard to this topic. I write this with the hope that it will be a jumping off point for future examinations of many other socially relevant issues related to consciousness through a lens that integrates both philosophical and neurobiological perspectives. I maintain that such an integration will inform our ethical thinking and decision-making in a way that neither perspective alone could do.

I think that it is fair to say, based on my readings, that most animal rights activists are driven primarily by a commitment to decreasing the suffering of animals. For example, according to Donald Graft, "It is [animals’] alleged capacity for suffering that motivates animal rights activists to seek to extend the circle of compassion to non-human animals" (Graft, web source). Yet, inherent in this line of thinking is the assumption that all animals are capable of suffering, and there is reason to critically examine this presumption from a neurobiological perspective. Since meaningful linguistic communication with animals is not possible, our concepts of the existence and nature of animals’ internal states are generally based exclusively upon their external behaviors. When it comes to evaluating suffering, those who adhere to an animal-right’s philosophy maintain that overt pain behaviors are indicative of suffering. This is reflected in a lot of their writing in which they often use the terms "pain" and "suffering" interchangeably, as if they are synonyms. Yet, there is research that reveals that from a neurobiological perspective, the existence of pain sensation and many of the associated pain behaviors is distinct from the experience of pain, which is, presumably, a prerequisite for suffering. There is contemporary philosophical grounding for the ethical stance against the use of animals for experimental research, the food industry, or a wide range of other purposes. The philosophical basis of the animal rights movement, in many respects, grows out of the utilitarian tradition and the work of Peter Singer, who builds his theories largely upon ideas put forth by 18th century English philosopher Jeremy Bentham (Best, 2000, web source). Utilitarianism maintains that the best deed is that which brings the greatest amount of pleasure to the greatest number of people. Singer is often cited as the world’s leading proponent of this utilitarian perspective (though he clearly would take issue with the final prepositional clause in the preceding sentence). In his book Animal Liberation, Singer reasons that the ability of animals to feel pain and pleasure means that they belong on a plane of moral equivalence with humans (Singer, 1990a). In an excerpt from this book, Singer quotes Bentham’s view that in considering the moral standing of animals, "The question is not, Can they reason? nor Can they talk ?, but, Can they suffer ?" (Singer, 1990b, p 23). Reflecting on this quote, Singer agrees with Bentham that the capacity for suffering is the crucial characteristic that grants a being the right to equal consideration. He argues that the ability to suffer is a much less arbitrary place to draw the line between those that do and do not have interests that need to be taken into account than the ability to reason or use language. After all, he argues, the ability to suffer and enjoy is a prerequisite for possessing interests at all. According to Singer, the capacity for suffering and enjoyment is not only necessary, but also sufficient for it to be established that a being has interests (Singer, 1990b). Singer, himself writes, "If a being is not capable of suffering, or of experiencing enjoyment or happiness, there is nothing to be taken into account. So the limit of...capacity to suffer...is the only defensible boundary of concern for the interests of others" (Singer, 1990b).

With that established, the central issue that now inevitably arises is how to determine if animals are capable of suffering. In an article entitled "Do Animals Feel Pain?", Singer moves outside of the realm of philosophy to make some arguments to support his belief that this question should be answered in the affirmative. Yet, in doing so, he makes some assertions that can be challenged from a neurobiological perspective. In fact, the entire premise that if one can establish that animals feel pain, then it is a given that they can experience pain and suffer is potentially flawed, as we will see when we examine the work of Demasio in the second half of this paper. Within the article, Singer points out that almost all of the external signs of pain seen in humans are seen in animals, including behavioral signs such as writhing and moaning. In addition, animals manifest similar physiological responses, such as dilated pupils and perspiration, under circumstances in which we know we would experience pain. He takes this as evidence that animals must be experiencing pain as well (Singer, 1990c, web source). However this assumption is problematic because, as will be discussed further, the brain is certainly capable of sending out motor messages to the body, based on sensory pain input, without involving the "I" function at all (Grobstein, Biology 202, 2000). He then goes on to make an evolutionary argument that animals must be able to feel pain because an ability to do so is evolutionarily advantageous as it leads members of a species to stay away from sources of injury (Singer, 1990c, web source). This is a big jump because while it certainly is evolutionarily adaptive to be able to respond to pain by performing a behavior that enables you to avoid the injurious source, a conscious experience of the pain is not necessary in order to initiate such a behavior.

Philosophers such as Singer throw terms like "suffering" around without any concrete notion of how to critically evaluate its existence, which can leave those who have more of a scientific bent, a bit unsettled. The work of Marion Stamp Dawkins, who studies animal behavior at Somerville College, Oxford, is more quantitative in defining suffering and proposing experimental procedures that, in theory, could be used to examine suffering. Yet, as we will see, there are problematic aspects of her approach, which relies heavily upon behavioral output as indications of suffering, a measure that may not be valid. Dawkins asserts that there are two main strands that are discernible from the "bowl of spaghetti-like reasoning" that we utilize as the ethical bases for our treatment of animals: in general, we value animals which appear clever or which demonstrate proof of the ability to reason and we value organisms which show evidence of the capacity to suffer and to feel pain (Gribble, web source). Dawkins defines suffering as states in which an animal would prefer not to be and from which it would most likely try to flee if it had the chance. Aware that animals do not have the means to inform humans of their states of suffering through language, she offers three alternate sources of evidence: the overall state of health of an animal (for example, squealing, struggling, convulsions), physiological states (for example, increased heart rate, brain activity, hormone levels) and manifest behavior (Dawkins, web source). Dawkins refers to a 1978 experiment reported by A.P. Silverman in Animal Behavior as an example of behavioral evidence of an animal being in a state of suffering. Rats were put into air-tight containers and exposed to tobacco smoke. Over time (she does not indicate how long), the rats learned to stop up the smoke-vents with their own feces, thereby expressing, in Dawkins view, "what they thought of what was being done to them" (Dawkins, web source). Dawkins goes on to propose experimental procedures that she believes could be implemented in order to figure out the degree to which an animal is suffering within a particular state. The main experimental evidence of suffering in her model is behavior that demonstrates that the animal is "working hard", defined as expending energy or sacrificing food, to try to escape (Dawkins, web source).

The problem with Dawkins approach is that it relies on the idea that there is a strict correspondence between how one behaves and how one feels. Throughout this paper, I have alluded to the idea that there is neurobiological evidence for a dissociation both between pain behaviors and the experience of pain and between the experience of pain and suffering. I now aim to set forth the evidence to support this claim. To do so, I turn to the work of Antonio Demasio, in his book The Feeling of What Happens. Recall that both Singer and Dawkins point to external behavioral signs of pain (e.g. writhing) and physiological changes (e.g. increased heart rate) as signs of suffering in animals. After all, they reason, we know that when those changes manifest themselves in us, they are almost always accompanied by the experience of pain and suffering. Yet, as Demasio eloquently points out in his book, pain and the experience of pain are by no means universally equatable phenomenon. Since only in the latter case is there even the potential for suffering, the distinction is meaningful in this discussion, and therefore, should be further explored. The way that I conceptualize it, there is a progression along a spectrum beginning with the physical sensation of pain (often referred to as nociception in order to distinguish it from the more colloquial use of the word "pain"), extending to the experience of pain, and then at the far end of the spectrum is suffering, which, as we will see, can be distinguished from the experience of pain.

Demasio points out that if one’s hand were placed on top of a hot stove while the brain was in an unconscious state, the self-less brain would nonetheless receive nociceptive (pain) neural patterns produced as a result of tissue damage, and would generate a series of behavioral responses. In addition to the withdrawal of the arm from the stove, other emotional responses would automatically occur as well, including alterations in facial expression and variations in heart rate. The point is that while all of these behaviors in response to pain take place in conscious human beings, consciousness is not a prerequisite for the responses to occur (Demasio, 1999). This reveals the problematic nature of Dawkin’s use of behavioral measures as indications of an animal’s capacity to suffer. While it is true that the physical sensation of pain can be observed from overt behavior, it should now begin to become clear that to count behavior as absolute evidence of experiencing pain, much less suffering, is not valid.

In a more general sense, there is evidence for a dissociation between how one behaves and what one is capable of feeling/experiencing. Two clinical conditions, namely locked-in syndrome and blindsight, offer clear proof of this dissociation. A person who has locked-in syndrome has an intact consciousness (i.e. they are awake, alert, and conscious of their mental activity), yet cannot move any muscle in their entire body, and thus cannot perform any behavior, save the vertical movement of the eyes. The condition results from anterior lesions to the pons or the midbrain, and illustrates the ability to experience but not behave (Demasio, 1999). On the other hand, a person who manifests a condition known as blind-sightedness, completely denies the experience of seeing anything, yet, when asked to guess the possible location of an object, will point in the correct direction with a frequency well above chance. In this case, the person is able to exhibit behaviors in the absence of having any visual experience (Demasio, 1999).

Having laid out evidence for the dissociation between how one behaves and how one feels, both in the context of pain and on a broader scale, we now move to a comparison between the experience of pain and suffering. As we will see, one can have an experience and awareness of pain, completely devoid of suffering.

Throughout his book, Demasio relates the stories of a number of his patients, most of whom have brain lesions that reveal something about the nature of issues related to consciousness. A relevant example for the present purposes concerns a man who suffered from a debilitating case of refractory trigeminal neuralgia in which even the lightest touch of the skin or face would provoke an agonizing pain. Having found all known pain medications to be ineffective, the poor man is said to have spent his days hunched in the corner, immobilized by his condition. As a last resort, surgery was performed in which small lesions in a specific part of the frontal lobe were made. Demasio recalls that when asked about the pain two days after the operation, the patient reported that "the pains were the same", but that he felt fine now. From a neurobiological perspective, nothing had been done to alter the sensory input patterns signaling local tissue dysfunction coming in from the trigeminal system. Furthermore, because the mental images of the tissue dysfunction were not changed, the patient still had the awareness and experience of pain. And yet, while he was still experiencing the pain, as a result of lesioning the frontal lobe, the suffering was completely gone (Demasio, 1999). One might take this case study as evidence that it is the frontal lobe that mediates organisms’ capacity to suffer, which would lead to the conclusion that any organism that does not have a highly developed frontal lobe is incapable of suffering. However, I would find any such argument to be overly simplistic and misguided from the neurobiological perspective. Clearly, different organisms’ brains have developed under different environmental pressures, and therefore, it is possible that regions of the brain other than the frontal lobe can mediate suffering in non-human animals. Rather, I use this case study as an illustration of the dissociation between the experience of pain and suffering.

Another problem with the experimental criterion that Dawkins proposes as evidence of suffering is that it seems that they could be satisfied by an artificial being. Recall that the standard that Dawkins puts forth is based in an organism’s ability to behaviorally demonstrate that it is working hard to try to get out of a situation that it would rather not be in (Dawkins, web source). As Paul Gribble point out, it seems that it would be entirely possible for a mobile floor-sweeping robot constructed out of heat-sensitive material to "suffer" under this definition of the concept. Imagine that in addition to heat sensors, the robot is equipped with crumple-detectors, so that when its outer layer begins to crumple from any form of impact, it will reverse the direction of its movement. Say that a student lured this robot into a room by dropping a trail of cookie crumbs, and then locked the door and turned up the heat. When the robot’s heat sensors begin to detect heat levels significantly above its pre-programmed thresholds, the robot will begin to move around the room, only to discover that its detectors register excessive heat levels throughout the room and the door is locked. Since the robot has been programmed to consider heat regulation as its top priority, it will roll itself to the back of the room, and then throw itself forward into the door, ignoring the warning messages from its crumple-detectors. In the scenario described, it is evident that the robot is in a state in which it would prefer not to be and is working hard to escape the situation, even at the expense of possibly severe structural damage. Therefore, it satisfies Dawkins criterion for suffering, and its interests have been revealed. Thus, according to Singer, we are now morally obliged to consider its interests. Clearly this conclusion is incredibly disturbing, and therefore, we are strongly inclined to want to modify the criteria used to determine suffering in a way that eliminates artificial beings. Yet, when we consider doing so, we quickly realize that we are, in a sense, trapped. In an effort to make these criterion stricter, we would need to utilize more internal or subjective measures than the external, objective behavioral standards suggested by Dawkins (Gribble, web source). But any move in such a direction will come under attack by Thomas Nagel, who argues that it is impossible for a human to envision what it is like to be another organism (or an artificial being for that matter), precisely because a human is not that organism or being (Nagel, 1981).

So where does all of this leave us in terms of gaining insight into whether animals are capable of suffering? We are, in many ways, left in a very tough bind. As this paper has revealed, there is, from a neurobiological point of view, a great deal of uncertainty inherent in approaches that attempt to infer the experience of feelings, much less suffering from external behavior. In addition, there is valid concern that theories of suffering that rely solely upon behavioral measures are inadequate because, as demonstrated, artificial beings can meet the behavioral criteria for suffering, though they experience nothing. Nagel strongly cautions us against getting any idea in our mind that we would be able understand the subjective experience of other organisms. Nagel uses the bat as an example in his writing. According to Nagel, even the best, most informed attempt on my part to imagine being a bat would yield only a sense of what it would be like for me if I were a bat. And that is not what is at issue; rather our concern is with what it is like for a bat to be a bat, and whether, as a bat, a bat is capable of suffering (Nagel, 1981).

So, after an exhaustive examination of the issue, it seems clear that, at least at this point, it is not possible to show when suffering occurs. My sense is that with time, as more and more is discovered about the brains of humans and other organisms, we may develop better ways to assess whether animals are suffering. Yet, even under the best of circumstances, this judgment will never be perfect. Therefore, as far as the ethical issue stands, the question really comes down to a decision about how willing we are to lean over backwards in order to avoid the unfounded, but irrefutable possibility of potentially causing suffering in animals.

Works Cited:

Best, Peter. "Life and Death Ethics: The Passion and Paradoxes of Peter Singer". http://www.britannica.com/bcom/original/article/0,5744,3576,00.html

Damasio, Antonio. The Feeling of What Happens–Body and Emotion in the Making of Consciousness.. New York: Harcourt Brace & Company, 1999.

Dawkins, Marian Stamp. "The Scientific Basis for Assessing Suffering in Animals". http://www.animalconcerns.org/ar-voices/assess.html

Graft, David. "Animal Suffering". http://www.animalconcerns.org/ar- voices/anim_suffering.html

Gribble, Paul. "Cognitive Science and Animal Rights". http://www.etext.org/Zines/Intl_Teletimes/Teletimes_HTML/cognitive_science.htm

Grobstein, Paul. "Biology 202: Neurobiology and Behavior", Bryn Mawr College, Spring 2000.

Singer, Peter. Animal Liberation. New York: Avon Books, 1990.

Singer, Peter, "All Animals are Equal" in Harnack, Andrew (Ed.), Animal Rights, Opposing Viewpoints, San Diego: Opposing Viewpoints Series, 1996.

Singer, Peter. "Do Animals Feel Pain?". http://arrs.envirolink.org/ar-voices/pain.html


Name: Libby O'Hare
Username: eohare@brynmawr.edu
Subject: The Evolution of Consciousness
Date: Sat May 6 00:49:32 EDT 2000
Comments:

Discovering the Mind: An Evolutionary Perspective on Consciousness

Some consider understanding consciousness to be the last frontier of science. Although we have a good understanding of the physical properties of the brain, for example: neurons, synapses, sensory inputs and outputs, we are still a far cry from understanding how the concrete brain produces the abstract mind. Understanding consciousness is an even more distant goal. Philosophers are still debating on how to define consciousness! Nevertheless, there are some biological components of consciousness that can be investigated. One of the most important of these is the evolution of consciousness. Just as the mind is a product of the processes of evolution, so are all of the properties that comprise it. Why did conscious states evolve? What benefits does consciousness provide to an organism? Attempts to answer these questions may help further expand our comprehension of consciousness.

The following paper will examine the current thinking on the evolution of consciousness. The first part of the paper will briefly examine the process of evolution and humans place within nature. The second part of the paper will look at consciousness (or aspects of it) in other animals, in an attempt to give an evolutionary background to the topic. The final section will examine two current theories that have been offered to account for the emergence of consciousness in evolution. The two questions above will guide this exploration into consciousness, although I make no claims about being able to answer either of them! Much more research needs to be done in the field before those questions can be answered completely.

The principles of evolution unite and guide the field of biology. The three major themes of evolution are random change, natural selection, and adaptiveness. For a new morphological or behavioral trait to appear on the scene (and subsequently in the fossil record), an individual must possess a trait that gives it some kind of advantage over other individuals of the same species. Most often, this advantage is environment specific. Any new trait arising out of random genetic mutations must confer some kind of survival advantage to the organism who possesses it, or the organism will not live to reproduce and pass on the new trait to its offspring.

It is all too easy to look at the seemingly gradual progression of evolution and artificially impose a hierarchy (Lewin, 1998). This reflects a bias that man is the ultimate output of a process designed to create the most perfect organism. These assumptions rest largely on the apparently unparalleled intelligence of man, which has allowed our species to transform the world like no other before it. We know, of course, that this is not true. There are plenty of organisms that are exquisitely well adapted to their particular environment. Nonetheless, this thinking persists in varied forms of scientific and religious doctrine.

The nature of these anthropocentric beliefs is captured by complexity theory. This theory, in its extreme form, holds that the entire process of evolution has been a transition from the less complex organisms (bacteria) to the more complex organisms (Homo sapiens). Trends of increasing complexity can be documented objectively by looking at specific characteristics of body size. Other support of the theory comes from purely subjective observations about the successes of one organism in its environment. This is particularly the case made for the apparent dominance of man over all other living things. According to some staunch supporters of the theory, the human brain is the most complex thing in the natural world. After all, it has been our intelligence that has allowed us to inhabit almost every possible environment on earth. Other important "human qualities" that some suggest separate man from all other animals are language and consciousness. But how great is the divide between man and other primates on these issues? Recent work suggests that other animals, especially non-human primates do display some of the characteristics associated with subjective states and reflective thinking, which are aspects of conscious experience.

There are two major types of observations that have been put forth as evidence for consciousness in other animals. First, Marion Dawkins has suggested that the most appropriate litmus test for consciousness is the ability of an animal to make decisions based on emotional needs and reasoning. She proposes that to be conscious, it must matter to the animal whether the world is one way or another (Vines, 1994). In a controversial study, Dawkins demonstrated that the domestic hen will do something it finds unpleasant (squeezing through a small gap) in order to obtain a pleasurable reward. Dawkins argues that this proves that hens have feelings and that they can act on these internal states. However, her work makes does not show that the hen is aware that she has internal states, in the way that a person knows she is sad or happy. Critics have argued that all Dawkins has demonstrated is that hens act according to instincts. What animal wouldn't do something unpleasant to achieve a food reward? Nevertheless, Dawkins' work is useful in that it links consciousness to observable behavior by way of the awareness of emotional states.

The most convincing work on consciousness in other animals has come from primatology. Indeed, many people find it much easier to accept the possibility that a chimp has consciousness than a chicken. Scientists have been developing tests to assess levels of functioning that they say are the prerequisites for consciousness. The requirements for consciousness include the ability to overcome instinctive behavior, being aware of oneself and others, and understanding that others have mental states (Pennisi, 1999). Some experiments have convincingly shown that chimps might have at least the beginnings of a theory of mind, or an awareness of the metal states of other chimps. Joesph Call and his graduate student designed an experiment in which three cages were lined up in a row. The middle cage contained two pieces of food. The interior doors of the cages were opened so that each chimp could see the food and the other chimp as well. When the doors were opened fully, only the dominant chimp approached the food and picked it up. However, when barriers were placed so that the dominant chimp could see only one piece of food and the subordinate chimp could see both pieces, a different out come was observed. When the doors were opened all the way, the subordinate animal approached and ate the piece of food the other chimp couldn't see. This implies that the subordinate chimp had some understanding of the perspective of the other chimp and he was able to modify his behavior accordingly. Critics argue that there is a big difference between seeing and perceiving and knowing and believing (Pennisi, 1999). Even so, this work lends strong support to the initial formations of a theory of mind in chimpanzees. It makes the dividing line between humans and our closet biological relative a little fuzzier.

Recognizing conscious behavior in animals gives us some hints as to why consciousness might be adaptive. For social animals like humans, the great apes, and the social carnivores (the big cat families), being able to predict the mental states of others in the group has clear survival implications. Human beings may have perfected consciousness by developing the ability to be self-aware, but clearly we are not the only animals to possess the fundamentals of consciousness. There have been many theories put forth to account for the emergence of consciousness during evolution. As we shall see many of these theories leave several questions unanswered. Nevertheless, it is still useful to examine the advantages and disadvantages of each one.

There is a fundamental paradox associated with the evolution of consciousness. Since human consciousness (as defined by Humphrey) is the subjective experience of being alive, consciousness is in the private domain. That is, the subjective quality of sensations are fundamentally individual, private qualities. How then could natural selection operate on something that has no overt component? Nicholas Humphrey suggests the following scheme for the evolution of consciousness.

Sensations began their evolutionary life as bodily behaviors. The action of sensing red would have involved responding to red in a certain physiological manner. The subjective experience of red would have been the experience of your body performing the physiological response. Whichever response was the most biologically adaptive in the presence of red would have been chosen for by natural selection. Over the course of evolution, these responses became less important to survival and the mental representation of the response became more important. The organism could only tell what kind of stimulation it had been experiencing by issuing commands for the original response and letting those commands represent the original stimulus. Eventually, this whole loop became closed off in an internal brain loop and differential responses stopped being subjected to natural selection. Senses and their subjective experience became private events. What started out as a bodily behavior corresponding to a particular stimulus now is the conscious experience of feeling the stimulus (Humphrey, 1994).

The theory has an advantage over others, in that it provides a series of steps to explain how something that is covert can be acted upon by natural section. Humphrey also gives a satisfactory account of how conscious behavior is more adaptive than non-conscious behavior. Unfortunately, the theory still makes a number of significant leaps. Humphrey does not explain why the mental representations of a response eventually became more important than the physiological response. He also doesn't explain why the loop became closed off from the external world. Finally, Humphrey attempts to explain the sensory aspects of consciousness, but he makes no effort to discuss the emergence of self-awareness, the feeling of knowing that sensations are happening to you.

A second theory, proposed by John Eccles, takes a different approach to the problem. His theory is more biologically orientated. He proposes that the organization the mammalian neocortex predisposed it to developing consciousness. Specifically, he suggests that the complexity of the human neocortex allowed for the formation of dendrons, which are packages of several thousand individual neurons and all of their branches. Each dendron is ensheathed by a psychon, or a mental unit. There are millions of poised synaptic vesicles on a dendron, which makes it extremely sensitive to psychon inputs. Eccles argues that consciousness arises from this interaction (Eccles, 1992). He admits that his theory cannot explain the quality of subjective experience, only how the cerebral cortex might have become adapted to produce consciousness. The major premise of his theory is that consciousness emerged when the cerebral cortex got really good at synthesizing information from many different inputs through the dendron-psychon interaction.

Eccles is never more specific about the dendron-psychon interaction. Also, his theory cannot account for the self-awareness component of consciousness. The major strength of his theory is that it is rooted in biological evolution. The neocortex has expanded more in the human than any other animal, and it makes sense to assume that the biological basis of consciousness will be found in this region of the brain.

Three main themes emerge from the experimental evidence presented above. First, we can learn a lot about the possible advantages consciousness confers on an organism from studying the various levels of conscious awareness in other animals, especially the great apes. By observing the advantages of consciousness in these animals we can gain a better understanding of how the same issues pertain to humans. A related issue is that most of the current theories of consciousness are unable to explain self-awareness, although they may explain subjective states. Some theorists have suggested that self-awareness can only occur concurrently with a spoken language (McCrone, 1994). This raises the possibility that this aspect of consciousness emerged only recently as a sort of "carry-over" from the development of language in Homo sapiens. The major problems with these theories is that they cannot be tested on animals that lack a spoken language, so it is difficult to imagine that research in this area will make any progress. Finally, this discussion has only raised several of the hundreds of theories about the evolution of consciousness. As with any complex issue, there are a number of theories proposed to explain it. There is still much work to be done in the field of consciousness research, but one must continue to wonder if consciousness will always remain a mystery.

References

Eccles, J.C. (1992). Evolution of Consciousness. Proceedings of the National Academy of Sciences, 89:7320-7324.

Humphrey, N. (Jan. 8, 1994). The Private World of Consciousness. New Scientist, 141:23-25.

Lewin, R. (1998). Principles of Human Evolution. Malden, Massachusetts: Blackwell Science.

McCrone, J. (Jan. 29, 1994). Inner Voices, Distant Memories. New Scientist, 141:28-31.

Pennisi, E. (1999). Are Our Primate Cousins Conscious? Science, 284:2073-2076.

Vines, G. ( Jan. 22, 1994). The Emotional Chicken. New Scientist, 141: 28-31.


Name: Allison
Username: arosenbe@brynmawr.edu
Subject: animal consciousness
Date: Sat May 6 01:19:03 EDT 2000
Comments:

Are Animals Conscious?

Consciousness is difficult to study because there is no single agreed definition for the term. Each person defines it their own way which leads to confusion and disarray when trying to come to any conclusions about where animals stand in this realm. I think consciousness should include an awareness of oneself as well as an awareness of one’s surroundings. Being aware of what other’s have in their minds is important for social animals because they need to know how to interact with others and also need to be aware of differing personalities and relationships between them.

There are two groups of people with differing opinions when looking at the controversial issue of animal consciousness. Opponents to animal consciousness refuse to believe that any species except our own has conscious experiences because there is no well-defined evidence to substantiate the claim that animals have conscious experiences. However, proponents of the issue already believe that other species such as dogs, cats and monkeys are fully conscious and that taking away from this belief would spoil the heartfelt connections some people have with their own pets. There are major obstacles in experimentation that need to be overcome, and to a certain point, can be overcome. Some experimenters have evidence that show that animals have some aspect of consciousness, but often times it is not as good as it appears at first sight. There may be flaws in the experiment and in the resulting data and people opposing animal consciousness are the first ones to point out those flaws. Regardless of the circumstances, there will always be scientists who find fault and try to disprove any substantial findings that may bring light to the issue.

People that don’t believe animals have consciousness hold the Descartian position that animals are assumed to lack the ability to attribute mental states until they are proven to be able to do so otherwise (Rogers, 1998). The people unwilling to allow any non-human species to enter into our human circle of consciousness claim that there is a difficulty that cannot be overcome when trying to distinguish animals from each other. For example, if we compare two animals, one with the inner eye that allows itself to look in on its own mind and its actions and the other which lacks this inner eye, they claim that it is hardly likely that anyone can differentiate between the two because no one knows what’s going on inside the animals head’s. “At a purely behavioral level, the two creatures might appear to be generally indistinguishable. Both might seem to be very intelligent and show emotional behaviors, including those we call “desires,” “moods,” or “passions.” The difference is that, for the unconscious animals, behaviors just appear to happen, achieved through some sort of psychological autopilot, while for the conscious animal, intelligent activities are accompanied by some awareness of the thought process involved (Coren, 1994).” From the outside everything seems identical, so how can we tell the difference between the two animals? The subjectivity of consciousness makes it incredibly difficult to evaluate. Humans experience emotion as internal and private feelings. It is not very difficult to know what consciousness is for oneself, but it is not as simple when thinking about consciousness of another person, let alone another animal.

Even with this skepticism, it is important to be aware that the most crucial aspect of feeling an emotion is that it matters to us. For example, if we have pain, we want it to go away, and if we have goals in life, we want to achieve them. We need to look for signs from animals to show that they care about what happens to them. This criteria might help us determine if animals have emotions. An interesting experiment was conducted in order to test the effects of cigarette smoke on animals. This test was not conducted to evaluate whether animals would express their opinions about what was being done to them, but nevertheless, the hamsters did just that. Living in a glass container, there was a stream of smoke constantly being poured into the container by a tube. Before long, the hamsters learned to stop the stream of smoke from entering their containers by using their own excrement to plug up the tube and block the smoke. Their message was made quite clear because these animals would rather asphyxiate themselves (since the smoke hole was also the only oxygen hole) than to continuously breathe in the smoke. In essence, they were telling the experimenter that what was being done to them was something that they wanted to avoid by any means possible (Dawkins, 1993).

Experiments that are being conducted to elucidate the issue of animal consciousness have had conflicting results. Often times, experimenters see connections and coincidences where none really exist, simply because they want to and are being hopeful and optimistic. They just have to realize they are doing this and try not to jump to premature conclusions. Besides this obvious and usually honest blunder, there are other complications that occur within experiments. For example, controlling experiments is very difficult because animals are able to pick up clues from each other and are adept at responding to cues from both their own species and from other species. At first glance, the “guesser-knower” experiment conducted with Povinelli’s chimpanzee Sheba seem to show that she has a theory of mind, that is, she has an awareness that people other than herself have minds and this needs to be taken into account when interacting with them. The experiment consisted of the “knower” putting food into one of four cups which were hidden from view. Both the “knower” and “guesser” are asked to pick which cup the food is under and from this information, the chimp is supposed to decide which cup she thinks the food is under. When Sheba chooses the same cup the “knower” pointed to, Povinelli assumes that she understands that both the “guesser” and “knower” have a conscious awareness of their own and that the “guesser” did not see where the “knower” put the food. Povinelli later conceded that the performance could have been the result of learning from hundreds of training sessions rather than a grasp of the knowledge states of others (Budiansky, 1998). When this experiment was performed multiple times, it is even more interesting to learn that another reason for the chimps success is that they merely learned to respond to subtle cues given by certain movements or directions of eye gaze of the testers. There were subtle differences between the way that the “knower” and “guesser” moved that the chimps picked up on that helped them in choosing the correct cup (Rogers, 1998). From this experiment we can see the difficult but necessary task of controlling experiments.

Researchers are in a bind with controlling the experiments that are performed. On the one hand, testing and rearing conditions need to be completely controlled or else risk the cognitive abilities that are displayed being criticized and not believed. But on the other hand, if the testing and rearing conditions are controlled, then the environment becomes sterile and the animals that grow up in that environment are less willing to display language abilities and possibly consciousness (Rogers, 1998). The situation is similar to humans who need long periods of time to recover from an accident. In a hospital, the recovery time takes much longer than if the person were at home because the hospital environment is cold, rigid, and unfeeling. This is not the most advantageous way to lead to a quick recovery, as it is not the most constructive way to have an animal display any cognitive abilities. Because of these restrictions imposed on the testing conditions of animals, it will be extremely difficult to prove beyond a doubt that animals have consciousness.

Although there is no clear cut answer to the question of whether animals possess consciousness, I think that evidence has been leaning towards humans needing to open their minds and be willing to share their circle of consciousness with a wider group of animals. An experiment that has not yet been done with animals that might elucidate the issue a little more involves questioning apes that have the ability to use sign language. Asking them to report what they are thinking at a particular time when they are awake might give us some insight into the thinking of other animals, but we also need to be realistic. Maybe what the ape is reporting will not be what they are thinking at that time, and only reporting the first thing that comes to mind when the question is asked. Their answer needs to be compared to their response when the same question is asked after waking them from REM sleep (Rogers, 1998). In humans, this is the time in the sleep cycle where people are most likely to remember their dreams. When awakened from this phase in sleep, the dreams become conscious and are able to be reported. Usually, the two answers are different in humans because people don’t usually dream about the same things they think about during the daytime. If the responses of the apes are different, then we might, for the most part, be able to conclude that the apes are reporting genuine thinking. Further experimentation needs to be conducted that might shed some more light on the situation and lead us to an answer for the question of whether or not animals are conscious.

References:

Budiansky, Stephen. If A Lion Could Talk. The Free Press, Simon & Schuster Inc, NY, 1998.

Coren, Stanley. The Intelligence of Dogs. The Free Press, Macmillan, Inc., New York, 1994.

Dawkins, Marian S. Through Our Eyes Only? W.H. Freeman, Spektrum, Oxford, 1993.

Griffin, Donald R. Animal Minds. The University of Chicago Press, Chicago, 1992.

Rogers, Lesley J. Minds of Their Own. Westview Press, Perseus Books, Colorado, 1998.

Wynne, Clive. 1999. “Do Animals Think? The case against the animal mind.” Psychology Today, 32:6: 50-53.


Name: adrianne lord
Username: alord@haverford.edu
Subject: PVS and Consciousness
Date: Sat May 6 11:28:29 EDT 2000
Comments:
Final paper

Persistent Vegetative State and Consciousness

In Damasio's book, "The Feeling of What Happens" he explores the creation and notion of consciousness through the use of new terminology and observations. The terms protoself, core conscious and extended conscious are interrelated and each have a separate purpose of making the individual aware of the presence of the internal state of 'self' and the 'self' as an entity separate from another object. Persistent vegetative state patients has similar characteristics to akinetic mutism and is assumed according to Damasio not to be conscious as well but this paper intends to suggest that PVS patients have extended conscious and ultimately core conscious based on their use of simple language.

What is PVS? About twenty-five years ago, Jennett and Plum first coined the term persistent vegetative state. They used PVS to describe brain-injured patients who have a 'continuing wakefulness without awareness'; patients emerged from a coma-like state and appeared awake but showed no sign of being aware of themselves or their surroundings. PVS can result from any injury that severely damages part or all of the cerebral hemispheres. The most common causes can be traumatic (i.e. motorcycle accidents and cardiorespiratory attack) or non-traumatic (i.e. a stroke or tumor). There is a lack of information regarding the prevalence of PVS in the United States but estimates have ranged from 10,000 adults to approximately 400 children. The vegetative state is distinct from a coma, which will be discussed later, and normally develops after being in a coma. There are a few cases where patients recovered from PVS after one year but with recovery patients are usually in a state of severe disability however, there are positive recoveries where the patients' voluntary motor function is intact. Two of the most important factors determining the outcome of PVS patients are age and duration of PVS.

PVS vs. Coma

Patients in persistent vegetative state appear to be awake with their eyes open, sleep-wake cycles preserved and able to breathe on their own without respiratory support but they fail to show evidence of awareness. On the other hand, coma patients have their eyes closed while in this state, lack voluntary movement, lack sleep-wake cycles and are helped by mechanical support for respiratory activity. The major differences between coma patients and PVS patients are the anatomical regions that are affected during an injury to the brain. In coma patients, the posterior region of the brain stem particularly, the reticular formation is damaged. However, in PVS patients damage is to the anterior portion of the brainstem damaging the pons but keeping the reticular formation relatively intact. The characteristics elicited by PVS patients such as opening of eyes, grimacing or moving their limbs, and being aroused by noxious stimuli is rooted in the brain stem. The reticular formation is involved in sleep and wakefulness which helps preserve the sleep-wake cycles and are usually "taken as a synonym for consciousness. " The brain stem, as a whole, is involved in pupil response, simple reflexes and alertness because it also influences the cerebral cortex. The brain stem controls the vegetative functions elicited by PVS patients which explains their ability to voluntarily track an object with their eyes, 'pull the sheets up while in bed' as well as have simple language (i.e. saying a word such as their name). These actions suggest that persons suffering from PVS need to be conscious but not necessarily aware because, in contrast to coma patients, there is voluntary movement and secondly, Damasio stated in his book that extended consciousness is needed to have language. The clinical features of PVS seem to suggest that PVS patients are possibly conscious under Damasio's terms but an understanding of Damasio's view on the relationship between consciousness and language is needed.

Types of Consciousness

Damasio proposes that protoself, core conscious and extended conscious play a role in how information regarding the self is processed. The main two concepts concerned with here are core consciousness and extended consciousness. According to Damasio, core consciousness is the knowledge that is processed during that moment in time to provide a mental image in your own perspective as well as involved in the establishment of memories, normal language operations and planning . From core conscious develops extended consciousness (not necessarily in a linear order) which encompasses the past and future of 'self'. Damasio states that abilities such as creativity, memory, reasoning and language have the presence of consciousness particularly, extended conscious and without consciousness language is difficult to express. The relevance of consciousness specifically, extended consciousness and PVS, is that Damasio classifies a patient with akinetic mutism as not being conscious.

PVS and Consciousness

Damasio's account of a patient L., a woman with akinetic mutism, raised the question whether or not patient L. was conscious because she did elicit language:

"She was to remain motionless and speechless for the best part of six months. She would lie in bed, often with her eyes open but with a blank expression. On occasion she might catch an object in motion....when asked about her situation she almost invariably remained silent, although, after much coaxing, she might say her name. "

As mentioned before, akinetic mutism is similar to persistent vegetative state. The ability for a person under these clinical conditions to say a word whether the word is his/her name or not demonstrates that there is some type of language abilities present. Damasio mentions that extended consciousness is needed for language and other creative abilities and also extended consciousness can not exist without having core consciousness, which appears to be connected with the reticular formation. With PVS patients having an intact reticular formation and the ability to create simple responses seem to suggest that Damasio needs to clarify what he means by language. According to Damasio, core conscious provides a mental image or representation of verbal accounts before it is vocalized. For PVS patients to have the capacity to state their name there needs to be extended consciousness within the individual. Regarding language the individual thinks beforehand, not necessarily consciously, about the mental words which will eventually become vocalized. In the case of Patient L., she stated her name after being coaxed. The nervous system (NS) does have an automatic reflex response to peripheral stimuli but the NS does not possess an automatic "response button" to state an individual's name. It appears then that PVS patients create a mental image of the word using extended conscious, in order to respond correctly to the question posed, and then responds. Moreover, when cortical regions are stimulated in PVS patients with visual stimuli there is cortical processing taking place meaning that something is happening inside of them. Based on observations of PVS patients and Damasio's definition of language, PVS patients probably have consciousness. Presently, science uses behavioral and electrical movements to characterize whether the patient is conscious which is difficult to determine since consciousness is a subjective state that is assessed by verbal affirmation.

Observations of motor reflex, vocal ability and respiratory activity suggest that PVS patients may be considered more conscious than comatose patients however, the distinction that needs to be made is the role of awareness and its importance in classifying an individual as conscious. PVS patients during and after recovery demonstrate that they are unaware of their actions but the notion of self-awareness is less defined and even more difficult to measure without verbal accounts. Currently, there is no way of being certain that measurements used to assess whether patients are aware or conscious while in vegetative-like conditions are accurate without being subject to scrutiny.

References

Damasio, A. (1999). The feeling of what happens: Body and emotion in the making of consciousness.

Howard, R., & Miller D. (1995). The persistent vegetative state: Information on prognosis allows decision to be made on agreement. British Medical Journal, Vol. 310

Menon, D., Owen, A., Boniface, S., & Pickard, J. (1998). Cortical processing in persistent vegetative state. Lancet, Vol.352, 1148-1149.

The persistence of mind. Lancet, Vol. 348 (1996)

Zeman, Adam (1997). Persistent vegetative state. Lancet, Vol. 350, 795-799.


Name: ...sarah...
Username: snosal@brynmawr.edu
Subject: consciousness and the 'near-death experience'
Date: Sat May 6 11:38:14 EDT 2000
Comments:
howdy all...the review for editing function isn't working...so if this is really sketchy...i apologize...sarah:)

Consciousness and the ‘Near-Death Experience’

In reading Demasio’s, The Feeling of What Happens, we were willing to take anecdotal evidence from individuals as a way to interpret current and previous states of consciousness, regardless of the physical manifestations of their state. Individuals who awake from comas claim to have experienced no conscious thought, and little perception, while individuals experiencing locked-in syndrome claim to be conscious yet reside in a body discontinuous from such thought. Thus, when addressing Near-Death Experiences, we too must be willing to accept claims from survivors that they were in fact conscious during their seemingly psychedelic journey to the beyond and back.

It has been estimated that 9-18% of individuals who have been near death but survived, have undergone a near-death experience (Greyson, 2000). It has further been revealed that nearly 40% of adult American’s claim to have endured a near-death experience at some point in their lives (Jansen, 1996).

A NDE experience has been defined as “a conscious perceptual experience in which the individual experiences a sense of being detached from the physical world during the process of physiological dying and death” (Filippo, 1991). In 1980, Kenneth Ring characterized the 5 stages of NDEs. The majority of ND experiencers, approximately 60%, experience a sense of peace, 37% experience body separation, 23% entering darkness, 16% seeing the light, and 10% entering the light. In 1998, Moody went on to characterize nine traits of the NDE. Among the NDE characteristics are: (1) a sense of being dead, (2) a sense of painlessness, (3) an out-of-body experience, (4) the sense of passing through a tunnel (5) an encounter with people of light (6) an encounter with a ‘being of light’, (7) a total life review, (8) rising rapidly into the heavens, and (9) a reluctance to return (Filippo, 1991; Jansen, 1996).

Some have argued that NDEs are merely religiously desirable manifestations brought on by either devout belief or fear of death. Moody, 1997, and Ring, 1980, have in fact shown that an individual’s religious beliefs and practices do not appear to significantly influence the extent and depth of a NDE. Additionally, Moody in 1998 found that children, at ages too early to fear death, also share a similar sequence of NDE happenings when they have been near-death, yet survived (Filippo, 1991).

An additional explanation as to claims of NDE is that perhaps NDEs are merely the manifestation of a dissociative manifestation in a very stressful circumstance. Dr. Bruce Greyson questioned 96 individual who had experienced NDEs and 38 individuals who had come close to death but had not undergone a NDE. While the level at which an NDE was experienced proved correlated with the extent of dissociative symptoms, the level of dissociative symptoms in general for ND experiencers was substantially lower than for a clinically dissociative population (Greyson, 2000). Greyson describes that “some people who come close to death report having had a profound experience in which they believed they left their physical bodies and transcended boundaries”. While retrospective studies indicate that individuals who experience NDEs tend to be psychologically healthy. Several theories as to NDEs and psychological dysregulation have been addressed. Earlier theories that “people faced with potentially inescapable danger attempt to avoid this unpleasant reality through pleasurable fantasies” or the theory that certain individuals experience childhood trauma that leads to a mechanism of dealing with stressful circumstances in a dissociative manner are both re-dispelled by Greyson. His own research is an experimental evaluation of the “frequency and type of dissociation among a sample of people who have had NDEs, and among individuals who came close to death, survived, but did not have NDEs” (Greyson, 2000).

As indicated previously, those who had experienced NDEs did prove to exhibit significantly more dissociative characteristics than a matched control group. They however exhibited significantly less dissociative characteristics than a clinic population. Since NDEs are quite rare it proves relatively impossible to do the kind of prospective study which would help eliminate the possibility that having experienced an NDE one is than more likely to report more dissociative symptoms, or whether one is more dissociatively inclined prior to the experience. Nonetheless, the most important aspect of these findings is that ND experiencers do not appear clinical in their level of dissociation and thus dissociative disorder proves a rather implausible conclusion for the NDE phenomenon. Greyson characterizes NDEs “[not] to be some pathological type of dissociation or a manifestation of dissociative disorder [but rather] a non-pathological experience that involves the psychological mechanism of dissociation as a normal response to intolerable trauma” (2000).

In an interesting article by Dr.James Whinnery explores experiences similar those of NDE phenomenon but in healthy individuals. The article investigates more than a decades worth of research on the effects of the G-force on individuals undergoing recorded military flight tests. Findings reveal that in the 15-20 seconds following black out and before return to wakefulness otherwise healthy military personal describe experiencing or have been observed experiencing: (a) tunnel vision and seeing bright lights, (b) feeling of floating, (c) out-of-body experience, (d) paralysis, (e) vivid dreams of beautiful places, (f) prior memories and thoughts and several other experience suggested of the NDE states (Whinnery). It is believe that the induction of cerebral ischemia, disruption of blood flow to all of part of the brain, as a consequence of high g-force circumstances results in individuals sharing may of the same experiences as individuals who claimed NDEs. Whinnery proposes these experiences as the steps through loss and return to consciousness. Anecdotal evidence and adherence to Demasio’s definition of core and extended consciousness, minus the proto-self, may indicated that NDE individuals, although appearing unconscious to the world, are in fact experiencing a state of consciousness.

Another way to induce the near-death experience is through the administration of ketamine, a “short-acting, hallucinogenic, ‘dissociative’ anesthetic”, (see figure). Dr.Karl Jansen indicates that NDEs are actually caused by the brain’s neurochemical response to the potentially damaging excitotoxicity from the neural flood of glutamate (Feldman, 1996). This glutamate deluge occurs subsequent to those physiological characteristics which often precipitate an NDE, “low oxygen, low blood flow, low blood sugar, temporal lobe epilepsy, etc.” (Jansen, 1996). The neurochemical response is hypothesized to be an, as of yet unidentified, ketamine like ligand, which blocks vulnerable NMDA (N-methyl-D-aspartate) receptors to the over excitation of the glutamate flood. Remarkably, ketamine administration has been shown to reproduce those same characteristic aspects of a NDE except in healthy, non-dieing, individuals. Studies by Rumpf et al, 1969, and Segal, 1978, found that thirty percent of the subjects administered ketamine who then experienced similar near-death type phenomenon insisted that they had not been dreaming or hallucinating but the events really had happened and they had in fact been conscious (Jansen, 1996).

Given that a biological correlate has been established, it would seem likely that a wider range of individuals might be willing to believe in the plausibility of the Near-Death Experience. If that is so, let us complicate matters.

The specific aspect of the out-of-body experience (OBE), a key component in the experience and definition of the NDE is reported to have been experienced by nearly a ¼ of the population, all in non-drug induced, non-life threatening situations. The majority of OB experiencers do claim to have been in a calm state at the initiation of the experience (Twemlow et al., 1982). Twemlow’s work is based on the assumption that “an objective separation of mind from body is possible and that the mind can have an existence independent of the body” (1982).

The out-of-body experience has been defined as, “an experience where you felt that your mind or awareness was separated from your physical body” in which you experience “a sense of location of the total sense of self at some place other than in the physical body” (Twemlow et al., 1982). One individual describes this experience in the following way

"When I was approximately 10 years old I was living together with my older brother at my uncle’s house, a major in the US Army Medical Corps. One day I was reclined on my bed quite awake and was looking at the ceiling beam of the old Spanish building where the living quarters were located. I was saying to myself many questions such as what was I doing there and who was I. All of a sudden I get up from the bed and start walking toward the next room. A that moment I felt a strange sensation of weightlessness and a strange mix of sense of a feeling of joy. I turned back in my steps in order to go back to bed when to my surprise I saw myself reclined on the bed. This surprising experiences at that very small age gave me the kind of jerk which, so to say , shook me back to my body."

Similar to those experiencing NDEs, there proves no increase in psychopathological levels among the individuals who had undergone OBEs although they did prove to be slightly more well educated than the none OBE group. During their OBEs individuals described a great vividness of reality accompanied by the “sense of separation of the total self from its normal location in the head but also being aware that this self existed in the same environment as the physical body” (Twemlow et al., 1982). This same tendency for awareness of a separation from the physical body is experienced in the OBE component of the NDE (Filippo, 1991).

Having examined the scientific element of the NDE must we now come to terms with a neurological correlate of the out-of-body experience? Is it possible that such a state exists, within the realm of consciousness where the essential momentary self, core consciousness, as well as the self with a past, present, and future, the extended consciousness, can exist without the emotion/the experience, the proto-self (Demasio, 1999). I like Twemlow will refrain from attempting to answer the question as to whether the mind really separates from the physical body, but the conscious recollections of an out of body experiencer is that this was in fact the case. For all the oddities of the experience of the complete functioning of self outside the brain, individuals maintain that “there is no clouding of consciousness as is reported in dream states…[as OB experiencers were] absolutely certain that they were not dreaming” (Twemlow et al., 1982).


Name: ...sarah...
Username: snosal@brynmawr.edu
Subject: oops...references...
Date: Sat May 6 11:44:46 EDT 2000
Comments:
Consciousness and the 'Near-Death Experience'
References

Carlson NR (1998) Chapter 4: Psychopharmacology - Neurotransmitters and Neuromodulators. Physiology of Behavior. Needham Heights, MA: Allyn and Bacon

Demasio AR (1999) The Feeling of What Happens: Body and Emotion in the Making of Consciousness. New York: Harcourt Brace & Company

Feldman RS, Meyer JS, Quenzer LF (1996) Chapter 10: Amino Acid Neurotransmitters and Histamine. Principles of Neuropsychopharmacology. Sunderland, MA: Sinauer Associates

Filippo DS (1991) The Consciousness of Near-Death Experiences.

Greyson B (2000) Dissociation in people who have near-death experiences: out of their bodies of out of their minds?. The Lancet.

Jansen KJ (1995) Using Ketamine to Induce the Near-Death Experience: Mechanism of Action and Therapeutic Potential. Yearbook for Ethnormedicine and the Study of Consciousness 4: 55-81

Twemlow SW, Gabbard GO, Jones FC (1982) The Out-of-Body Experience: A Phenmenological Typology Based on Questionnaire Responses. American Journal of Psychiatry 139(4):450-455

Whinnery JE (DATE) Loss of Consciousness and Near-Death Experiences. National Institute for Discovery Science: Technical Report #1


Name: Rehema
Username: rtrimiew@brynmawr.edu
Subject: Evolution of self awareness
Date: Sat May 6 16:13:17 EDT 2000
Comments:
Damasio writes that "consciousness is the critical biological function that allows us to know joy, know suffering or know pleasure, to sense embarrassment or pride, to grieve for lost love or lost life."(Damasio, 1999) The critical aspect of consciousness is the knowing of all of these states that our body is experiencing. Why is this knowing or awareness critical, and how has it given our ancestors an advantage in the struggle for survival? By examining the data on animals, I will try to better understand what role consciousness plays in their lives and the role it might have taken in human evolution. I will also look at instances in humans in which awareness is altered or distorted in some way to better understand its function. As Damasio said, consciousness is a critical biological function, which is presumed to set humans apart from other animals. However, little is known on why we actually possess it and what it might be for. I will try to examine this and present current hypotheses that atttempt to explain the emergence of awareness in the human evolutionary course.

We may first turn to the usefulness or advantage of consciousness to see how it may have benefited early humans. What can be done consciously that can’t be done unconsciously? In blind sight studies, people with damage to the striate cortex (visual cortex) are presented with pictures. These patients claim that they are not aware of seeing anything in their corresponding visual field. Weiskrantz presented patient D.B. with lines, flashes of light, and X’s and O’s that only appeared in his left visual field, he claimed that he was not aware of anything there. When asked to guess about what he might have seen and where, he was very accurate though he claimed to have seen nothing. So even without awareness some part of his brain correctly interpreted visual information. In another similar study a patient with Balint’s syndrome was presented with two drawings, one with a house on fire and the other a normal house. She reported no conscious difference between the houses, however when asked to point to the one she would rather live in she always choose the house without flames. In addition, split brain studies indicate similar findings. So, if people with certain types of brain damage can process visual information and make informed responses, what is the usefulness of consciousness?

We may be looking at consciousness from the wrong point of view. Possibly, consciousness had to exist so that other functions of the mind could exist. Without ever having had consciousness, things like language, forethought, and other behaviors could not have come into existence and given organisms possessing these traits an advantage. Also consciousness may have come about gradually and not as an either/or type of functioning, but as gradual levels increased, so did advantages.

Humphrey explains that awareness gives us access to parts of our minds that allow for planning ahead and forethought. Essentially it allows us to conceive of multiple future actions and then to choose out of those the most effective or advantageous and then to follow that. "Consciousness allows us to project the workings of our own minds on to those of others in order to calculate what they are going to do. Consciousness, then, may well have evolved because of its adaptive advantages for us, both as internalized device for testing possible future events, and for projecting on to others that capacity for such internalized testing and predicting the consequences for their behavior."(Klein, D, 1984)

Detached representations are useful and would seem to have benefited the organism evolutionarily. "If the organism carries a small scale model of external reality and of its own possible actions within its head, it is able to try out various alternatives, conclude which are the best of them, react to future situations before they arise, utilize the knowledge of past events in dealing with the present and the future, and in every way react in a much fuller safer and more competent manner to the emergencies which face it." (Gardenfors, P, 1995) This is the inner environment where the detached representations occur. Features of objects may be represented and future consequences of actions inferred. This metaphor for certain cognitive capacities offers an evolutionary advantage. They do not have to actually carry out trial and error activities but can simulate them and then carry out the appropriate actions. The more accurate the simulation, the more successful the animal will be.

A theory of other minds would be valuable in teaching and learning behaviors and would provide a definite advantage to those that could utilize it, we should examine whether consciousness is really needed for it. However, the same problem arises, one could behave as if something else had a mind, without having a mind itself. My, computer program "SAT Personal Trainer" that I had in high school treated me as if I had a mind that was aware and learned, that’s why it was so effective at teaching me techniques for improvement on the SAT’s. It adjusted to the information that I already knew and continuously adjusted to match my level of knowledge. My computer and its programs are not aware, however, they behave as if they have a theory of other minds. Could the animals that behaved in a way that would indicate a theory of other minds and have been selected for regardless of whether they possessed awareness or not? In any event if their behavior in experimental conditions matches the behavior of a presumed conscious being then we will assume that they are aware.

Speculating again that if one posses a theory of other minds then they posses a theory of their own mind, gaze following tests can be looked at. If chimpanzees know to look in the direction that someone gazes in, they can generally gain useful information. In the wild, they might direct their gaze to a predator or something else useful that they should be alerted to. Does this mean that they possess a theory of other minds, or a very handy behavior that has been selected for unrelated to awareness. Studies have shown that chimpanzees do indeed follow the experimenters gaze. However, when chimps need to interpret where another person’s eyes are directed and what they are seeing, they fail to fully understand, though they seemed to follow the gaze. Studies by Povinelli indicate that chimps will react when they see someone's face or are trained appropriately, but will not interpret what another is seeing and respond appropriately.

In Povinelli’s lab, chimpanzees became accustomed to playing games in which their vision was occluded by a bucket that they had placed over their head or by covering their eyes with their hands. After being trained to gesture for food when presented with an experimenter, they were presented with experimenters in varying situations of visual occlusion (a bucket over their head, blindfolded, etc.). If they generated a theory about what the other was seeing, then when the experimenters had a bucket over their head or were blindfolded, the chimps should not gesture at them because their theory of the experimenters mind would indicate that they could not see them. The chimpanzees gestured indiscriminately at the experimenters whether they could see or not. Under certain conditions, the chimps gestured to the experimenter that did not have their back turned over an experimenter that was facing the chimp to see it, but after restricting and manipulating the experiment, it was found that the chimps were only choosing based on what they had been trained on and not in response to a theory that they possessed of the other’s mind. However 2, 3, 4 year old humans passed the tests. By 3-4 years old, humans have determined that visual perception indicates a mental event and generally by 4 that visual perception creates mental events in their mind and in others. Gallup and Suarez also indicated that during the early developmental stages in humans in which they do not posses self awareness, they do not have a theory of other minds and can not predict and interpret what others are trying to do. They also found that around the time that humans begin to recognize themselves in a mirror, they also were beginning to develop empathy, altruistic behavior, self-conscious behavior, and synchronic play. Possibly consciousness is necessary for all of these behaviors.

Having a theory of other minds would be useful with deception. Deception can be defined as "Acts from the agent, deployed such that another individual is likely to misinterpret what the acts signify, to the advantage of the agent." An organism must have self-awareness to have a theory of other minds to deceive other minds. In addition they must be capable of detached representations to deceive and imagine others reactions. Deception could also play a part in mate selection. Females may be looking for mates that are going to supply some for of parental investment for their offspring. Males may want to make sure that the offspring is theirs if they are going to invest energy into the raising of the child. Thus deceiving the partner may be useful. Also deceiving yourself so that you seem more honest and genuine to your partner would help also. If you really did not intend to stay with your mate and help raise the child, but deceived yourself into thinking that you would may make you come across as more believable and more likely to be selected for as a mate. This extends into many parts of life in which it would be useful to come across as looking out for someone else's best interests, while really only thinking of your own. For self-deception to occur there must be a self to deceive, of course one may ask why even have a self if it must be deceived.

There are a couple of extended hypothesis that describe how self-concept or awareness may have evolved and how the theory of other minds may have also. The social intelligence hypothesis is pretty much what’s been described about the theory of other minds, and anticipating the behaviors of others. It mandates that group living and social complexity honed the awareness of other minds. However, this explanation does not seem to explain why only great apes and humans have self-conception and not other equally social animals.

The orthograde clambering hypothesis posits that self-conception evolved to maintain the arboreal lifestyle of the ancestors of great apes and humans. Because it is so complex to navigate within an arboreal system while possessing large body mass, those that predicted what the next branch that was stepped on would do and plan the appropriate branch to grab, would not fall and harm themselves, would survive to pass on more offspring. "Our hypothesis is that clambering in large bodied apes who negotiate a habitat that is fragile, unstable, noncontinuous, and unpredictable as a consequence of their body weight, is underpinned by a cognizance of one’s actions - an ability to engage in a type of mental experimentation or simulation in which one is able to plan actions and predict their likely consequences before acting."(Povinelli, Cant, 1995) They compare this level of understanding to that of an 18 month child. In addition, their model helps to explain some of the results from studies like the mirror response tests. "Our model explains - from an evolutionary perspective - why behaviors related to self conception (self recognition) appear to be limited to only the large bodied apes and humans." Povinelli, Cant, 1995)

The reinterpretation hypothesis suggests that there was initially no behavioral difference between those with self-awareness and those without. The only difference was the way that things were represented in the mind. Eventually the difference became important and allowed for the interpretation of information in new ways. "Nonetheless, because we suppose that these new behavioral patterns were constructed from a set of existing basic behavioral elements, it would be difficult to point to any particular behavior and claim that it was not present, or not in principle possible, prior to the evolution to the new system." (Povinelli, Giambrone)

We have not solved the problem of awareness or how it may have come into existence in humans. Though we know that awareness itself arises out of the nervous system we still can only speculate how it may have come to plan ahead, deceive, formulate detached representations, interpret others behaviors and all of the other behaviors discussed in this paper. What exactly awareness is physiologically, is still uncertain so with more experimentation and research the enigma of awareness should be better clarified and understood. However, explanations like the orthograde clambering hypothesis seem to account for the evidence of awareness in non-human primates and the existence of awareness in humans. Still, more research must be done to flesh out some of these theories and give a more substantial explanation.

References: Bogdan, Radu. 1997. Interpreting Minds. Cambridge: The MIT Press.

Damasio, Antonio. 1999. The feeling of what happens:body and emotion in the making of consciousness. New York: Harcourt Brace & Company.

Dawkins, Marian. Through our eyes only: the search for animal consciousness. Oxford University Press.

Ferrari, M & Sternberg, R. 1998. Self-awareness: it’s nature and development. New York: The Guliford Press.

Gärdenfors, Peter. Cued and detached representations in animal cognition. Behavioural processes. 1995. 35: 263-273.

Klein, David.1984. The concept of consciousness a survey. London: University of Nebraska Press.

Lockard, J., Paulhus, D. 1988. Self-deception:an adaptive mechanism? Englewood Cliffs: Prentice Hall.

Palmer, Stephen. 1999. Vision Science: photons to phenomenology. Cambridge: The MIT Press.

Parker, Sue & MsKinney, M. 1999. Origins of intelligence: the evolution of cognitive development in monkeys, apes, and humans. Baltimore: The Johns Hopkins University Press.

Parker, Mitchell, & Boccia. 1994 Self-awareness in animals and humans. Cambridge: Cambridge University Press.

Plotkin, Henry. 1998. Evolution in Mind. Cambridge: Harvard University Press.

Povinelli, D. J. & Cant, G.H.J. Arboreal clamboring and the evolution of self-conception. 1995. The Quaterly Review of Biology 70:4: 393-421.

Povinelli, D.J. & Giambrone, S. Inferring other minds: Failure of the argument by analogy. Philosophical Topics.

Rosen, D.H. & Luebbert, M.C. 1999. Evolution of the Psyche. Westport: Praeger.


Name: david
Username: dmintzer@haverford.edu
Subject: motor imagery
Date: Sat May 6 16:58:56 EDT 2000
Comments:
motor imagery

 

Visualization: the Mechanisms of Motor Imagery

Is there a link between the actions we are able to imagine in our minds and those that we actually produce? Visualization techniques have become a mainstay of professional athletics and an enormous industry has evolved around mental training clinics, videos and books. Most of these instructional methods rely on the notion that "The nervous system cannot tell the difference between an actual experience and one that is vividly imagined"(1) Take a look at here, here, and here for a couple examples of athletic trainers hawking this brand of pop psychology.

Sport psychologists claim that athletes are able to consciously improve their motor skills and reflexes just by thinking about their performance. There have been a number of studies which have consistently shown that such phenomena do exist (2). For example researchers found that visualization of receiving a volleyball serve improved actual performance compared to controls who did not use mental rehearsal techniques. Furthermore autonomic measurements such as skin resistance, temperature, heart rate and respiratory frequency during visualization correlated with measurements during actual performance.

Visualization or mental rehearsal involves an internal recreation of motor activity. Motor imagery is a primarily kinesthetic experience in which the individual senses that he or she is actually performing the actions. This phenomenon is distinct from visual imagery in which the individual acts as a third-person observer (3). Thus mental rehearsal requires a certain representation of the individual's own body in which a virtual generation of activity can occur. Where is the link between conscious internal representation of motor activity and actual motor performance? It has been proposed that mental rehearsal improves motor skills through either through cognitive means (familiarity with task, mental plans, etc) or through "a sub-threshold arousal of the normal motor output system which is sufficiently strong to generate kinesthetic sensations" (4). A third proposal hypothesizes that motor imagery is related to the preparation of motor activity, in that visualization involves the same mechanisms as actual motor output except that execution is blocked (5).

Driskell, et al (1994) found that tasks which had a greater degree of cognitive complexity, those that required more mental operations, benefited more from mental practice (6). This finding suggests that visualization affects cognitive factors more so than physical factors such as muscular strength, endurance and coordination (7). However, at the same time, several studies have identified physiological and neurological correlates which suggest that motor imagery is tightly related to actual motor output. One study actually found that mental training increased muscular strength to a similar degree as actual physical exercise. EMG recordings showed that high levels of muscle of contractions occurred during actual training but not during mental training. Nonetheless, the maximal force produced by the trained muscles increased significantly for both techniques. (8)

Investigating the dynamics of motor imagery and visualization presents us with the problem of accessing the subjects' subjective internal processes. Behavioral, physiological and neurological methodologies have been used. Chronometric behavioral methods involve instructing subjects to imagine performing a certain task and determining whether mental rehearsal is timed similarly as the actual performance. For example, it has been found that the time it takes to visualize walking to a predetermined target is relative to the distance covered. Duration also depends on task difficulty (e.g. walking on a narrow beam takes longer than on a wide beam) (9). These chronometric measurements help determine that the motor imagery is actually taking place and is consistent across subjects although compliance with the task instructions can never be completely assured.

Combined with autonomic and physiological measures and modern brain imaging techniques, these behavioral methods may reveal how the nervous system generates motor imagery. For example, For example, Decety, et al (1993) measured cardiac and ventilatory activity during actual and imagined running. They found that these measurements were highly correlated with running speed for both real and visualized activity (10). Furthermore, measurements of muscular metabolism found that there was no muscle activity during mental simulation. Electromyographic activity (EMG), which increases during motor stimulation also increases in those limbs involved in visualized movements. Jacobson (1931) found that EMG measurements were related to the requirements of the imagined task (such as rhythm) and Shaw (1940) observed that EMG increased relative to the amount of imagined effort (11).

Brain imaging studies have identified several cortical areas involved in actual motor output which are activated during motor imagery. PET and fMRI techniques have identified activation of the supplementary motor area, lateral frontal (premotor areas and cerebellum during visualization (12). Most studies have found that the primary motor cortex is not active during motor imagery, although more sensitive imaging techniques have determined that it may play a role (Porro et al, 1996. Pfurtscheller, 1997). These studies are often complicated by the different tasks used and the different sensitivities of the imaging techniques.

Studies of patients with brain lesions have also elucidated which neural mechanisms may be responsible for motor imagery. One study found that a patient with a lesion to the motor cortex was unable to successfully calculate the timing of imagined movements. Crammond describes a study which asked subjects to touch the tip of their thumb to each finger with a metronome pacing their speed (13). The subjects were also asked to imagine performing the task while listening to the metronome and identify the speed at which such finger manipulations would be impossible. Estimations of maximum speed during imagery were consistent with actual performance of the task. Patients with damage to the motor cortex performed the task slower than healthy subjects, but the mental imaging reflected this, suggesting they were able to successfully visual their actions. However, subjects with parietal lobe damage were unable to accurately identify the maximum speed of the task during visualization.

Other studies have examined the ability of patients with varying forms of paralysis to imagine motor movements. Cincotta, et al (1999) found that a patient with locked-in syndrome was able to visual movements. When she was asked to think about lifting her paralyzed left little finger, improved motor evoked potentials were observed (14). Johnson (2000) examined motor imagery with patients whose left or right arm was paralyzed due to cerebral brain damage. Most of these subjects were able to visual movements of the paralyzed limb, although those with posterior parietal or left frontal lesions could not (15). Finally, Decety found that the timing of imagined movements of hemiplegic patients was significantly slower for the paralyzed limb than for the unaffected limb. However, tetraplegic and paraplegic (patients with paralysis of both sides of their body) were able to visualize movements with timing comparable to normal subjects. These findings suggest exciting new possibilities regarding prosthetic limb control for paralyzed patients. A report in Science Magazine describes how Phillip Kennedy measured the neural activity of a paralyzed patient while he imagined moving his hand. He then implanted an electrode into the active region. The electrode released growth-promoting compounds that caused adjacent neurons to grow projections and attach themselves to the electrode. Consequently, when the patient thought about moving his hand, the electrode sent signals which controlled a cursor that spelled out words. Researchers have also built a robotic arm which mirrors the movements of a monkey's arm by monitoring the activity of neurons in the motor cortex. A better understanding of the neural representations of motor imagery may someday allow paralysis patients to control prosthetic limbs through visualization (16).

The data presented above suggests that motor imagery, and the consequential improvement of performance, does not rely primarily on actual activation of and feedback from muscle fibers. It seems apparent that motor images are generated by areas of the brain which are involved in actual generation of movement. This hypothesis suggests that these areas have an intact representation of the body which is not dependant on somatosensory feedback from the periphery.

 

 

1) http://family.go.com/Features/family_1998_02/melb/melb28rehearse/melb28rehe arse.html

2) http://www.rohan.sdsu.edu/dept/coachsci/vol26/table.htm

3) Jeannerod. (1995). Mental imagery in the motor context. Neuropsychologia 33(11) 419-1432.

4) http://www.swin.edu.au/aare/98pap/cha98030.html

5) http://www.cogsci.soton.ac.uk/bbs/Archive/bbs.jeannerod.html ; Bonnet, Decety, Jeannerod, Requin (1997). Mental simulation of an action modulates the excitability of spinal reflex pathways in man. Cognitive Brain Research 5, 221-228.

6) Driskell, J. E., Copper, C., & Moran, A. (1994). Does mental practice enhance performance? Journal of Applied Psychology , 79 , 481 - 492

7) http://www.swin.edu.au/aare/98pap/cha98030.html

8) Yue, G., Cole, K.J. (1992) Strength increases from the motor program. Comparison of training with maximal voluntary and imagined muscle contractions. Journal of Neurophsyiology, 65. 1114-1123.

9) Jeannerod (1995).

10) Decety, Jeannerod, Durozard, Baverel (1993). Central activation of autonomic effectors during mental simulation of motor actions in man. Journal of physiology, 461. 549-563.

11) Jeannerod (1995).

12) Ibid; Porro (1996), et al. Primary motor and sensory cortex activation during motot performance and motor imagery: A functional magnetic resonance imaging study. The Journal of Neuroscience 16(23), 2668-7698; Pfurtscheller, Neuper (1997). Motor imagery activates primary sensorimotor area in humans. Neuroscience Letters 239, 56-68.

13) Crammond (1997). Motor imagery: never in your wildest dream. Trends in Neuroscience 20(2), 54-57.

14) Cincotta, et al. (1999). Motor imagery in a locked-in patient: evidence from transcranial magnetic stimulation. The Italian Journal of Neurological Sciences 20(1), 37-41

15) Johnson SH (2000). Imagining the impossible: intact motor representations in hemiplegics Neuroreport 11(4), 729-32

16) Barinaga (1999). Turning thoughts into actions. Science, 286(5441). 888-90

 

Name: Peter Brodfuehrer
Username: pbrodfue
Subject: test
Date: Thu Sep 6 14:50:30 EDT 2001
Comments:
This is just a test.
Name: Peter
Username: pbrodfue@brynmawr.edu
Subject: test 2
Date: Thu Sep 6 14:51:28 EDT 2001
Comments:
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