Serendip is an independent site partnering with faculty at multiple colleges and universities around the world. Happy exploring!

Neurobiology and Behavior, Week 5

Paul Grobstein's picture

Welcome to the on-line forum associated with the Biology 202 at Bryn Mawr College. Its a way to keep conversations going between course meetings, and to do so in a way that makes our conversations available to other who may in turn have interesting thoughts to contribute to them. Leave whatever thoughts in progress you think might be useful to others, see what other people are thinking, and add thoughts that that in turn generates in you.

You're free to write about whatever came into your mind this week, but if you need something to get you started what's your reaction to the notion that all brains are "somewhat the same, somewhat different"?  to the idea that "action" is not an output (and objects are not an input) but instead a pattern of activity across lots of output (and input) elements, that there is an additional box, the "I-function"?


kgould's picture

My mind goes on random

My mind goes on random tangents during class. This can be good, bad, or neutral, but almost always interesting for my personal understanding of what we're talking about.

After talking about the "I-function" I immediately wondered about how Alien Hand Syndrome and Lesch-Nyhan syndrome come into play. For those not familiar with either, I can explain to the best of my ability:

-Alien Hand Syndrome: Essentially, Alien Hand Syndrome is a neurological disorder where one of the individual's hands seems to take on a mind of its own. This has been best documented in surgery patients who have had the two hemispheres of the brain separated, a measure sometimes taken to relieve the symptoms of extreme forms of epilepsy. The individual still has normal sensation in the affected limb, but feels a loss of agency or control over the actions that it takes. Alien hands can perform complex acts such as undoing buttons, removing clothing, and manipulating tools. Alien behavior can be distinguished from reflexive behavior in that the former is flexibly purposive while the latter is obligatory. Sometimes the sufferer will not be aware of what the alien hand is doing until it is brought to his or her attention, or until the hand does something that draws their attention to its behavior [1].

-Lesch-Nyhan Syndrome: L-N is a rare inherited disorder caused by the lack of an enzyme, leading to a build up of uric acid in all body fluids, which can lead to complications including severe gout and kidney problems, poor muscle control, and moderate mental retardation. A striking feature of LNS is self-mutilating behaviors, characterized by lip and finger biting, that begin in the second year of life. Neurological symptoms include facial grimacing, involuntary writhing, and repetitive movements of the arms and legs similar to those seen in Huntington's disease. The direct cause of the neurological abnormalities remains unknown.

A great article, "An Error in the Code" by Richard Preston, was originally published in The New Yorker and a .pdf of it can be found here. 

The general idea is thus: How does the "I-function" work and, then, what happens when it goes wrong? Are these two syndromes related to the "I-function?"

What do you think?

Congwen Wang's picture

The gradient in biology

(Sorry for the late posting)

I'm very interested in our discussion about the differences between brains of males and of females and how this only apply to population but not individual. My thoughts about that is, it is an other good example of the gradients in biology. For many traits - especially those in human brains - the difference among individuals is gradual. If we imagine different phenotype of a gene as an axis, we may see an end as "completely male" and the other "completely female", but most people's traits will probably fall between the two, and there are no breaking points on the axis. What biology always amazes me is the great diversity caused by the combination of these gradual differences among individuals. What is more, these gradients are not limited among organisms of the same species, but also through the line of evolution. When we look at brains of different mammals, we can see that as well. These gradients create infinite possibities of the biological world.

JJLopez's picture

Alot of ideas going through my mind

I think that the mind and the brain are separate yet the same simultaneously.  To me when I think about the brain, I think of a large organ that is the battery of the entire body.  It keeps everything functioning and when anything is disconnected from the battery it stops working as it should.  The mind, even though is a function of the brain, is focused more on the humanistic characteristics people have like thoughts and feelings.  I can understand now even better that because each brain is shaped and wired in slightly different than another brain resulting in many different thoughts and feelings and personalities, but it is the common patterns that these brains encounter that make people able to recognize those similarities in human behavior.  The example with Christopher Reeves left me confused.  Why would his toe move if it has no connections left to the brain? Does that mean that if his leg was stimulated in a certain way (significantly enough) he could move his entire leg or is it just the toes?

Raven's picture

Brain..same but different

After class I thought more about the idea that all brains are made of the same stuff with some well characterized connections but that this idea of plasticity within the brain allows for differences between people. So I read an article in Scientific American Mind about a new discovery of jumping DNA as a potential reason for neuronal plasticity and differences between people's brains which could create the individuality in personalities we This would be molecular evidence against the idea that there is a separate soul/mind.

I find the idea of the "I function" fascinating and I am excited to learn more about this. The idea that the mind can assess itself or that you can view you outside of your brain is suggestive of a second brain(mind/soul).

Riki's picture

so long, and thanks for all the fish

One thing I noticed this week in class was how humongous and seemingly developed a dolphin brain is. It looks like it has more sulci and gyri than a human brain, and it has a very defined interhemispheric fissure. The neocortex doesn’t seem to be as developed, however, which is consistent with the common assumption that humans are the most intelligent creatures on this planet and that higher intelligence lies in the neocortex.


Another thing I have been thinking about is Capgras syndrome and prosopagnosia.  Can you ever feel as though you yourself are an imposter? What does it feel like not to recognize yourself? Are emotional connections essential to the sense of self, or the I-function?


natmackow's picture

I-function, a more right explanation?

We first talked about Dickenson’s and Descartes’ definitions of the brain and mind and how we see the world around us. We discussed which theory each of us favored, or found more comforting. Did you like the idea that our thoughts and behaviors can be broken down into billions of neurons or the idea that the mind (one’s sense of self and ability to make decisions) is a separate entity from the body?

This past week’s discussion got us talking about topographical organization and patterns of neurons and the I-function. The idea that every human brain is different (and these differences correspond to differences in behavior) is, to me, more comforting than anything discussed by Dickenson or Descartes. While no motor neurons are specific for any type of behavior, the way in which all the neurons in the brain receive, process, and transmit information creates interesting and diverse patterns of motor neuronal activity (behavior). This slightly more empirical explanation for the individuality of human behavior feels more right to me.  In addition, the introduction of the “I-function” as the “box” containing a restricted sense of how we perceive our actions and ourselves was very interesting. I would like to learn more about this I-function and its connections to other parts of the brain and the body. If the I-function is related to how we see ourselves and control our actions, is it connected to personality? Could differences in connections to (or in) the I-function be responsible for individuals seeing themselves and their interactions in a distorted manner (BDD, delusions, social phobias, etc.)? What causes the extreme discrepancies in the “thoughts” of different individuals? Is our sense of self solely located in this I-function (I find this hard to believe, though the thought is intriguing)?


Kwarlizzle's picture

Interesting week

Slowly but surely, I find myself coming to believe in the 'brain according to Dickinson'. I still believe in a mind, but I am coming to see how the brain plays a greater role than I have given it credit for. The most important part of this week for me was Tuesday. The more similar we are, the more our brains have in common, but any differences we find between ourselves also manifest as a difference in the way our brains are wired (just like every mind is unique, but we can all think similarly, have similar mindsets, etc). That made a ton of sense to me.

As to Thursday, I am still trying to decide whether or not I agree with the 'I-function' philosophy (if it can be called a philosophy). I tend to agree with other posters on here who have noted that just because an action is iinvoluntary doesn't mean it isn't a part of myself. I am me - central nervous system, and peripheral nervous system; I am both my voluntary and involuntary actions; I am my thoughts, my actions, my instincts. And I don't know if I agree with the Christopher Reeves example. I am still thinking it through, so.....I'll get there...someday.

Schmeltz's picture


One of the questions posed in class this week was what was the main difference between mammals and other vertebrates.  I was thinking about this in terms of the nature versus nurture argument and also in light of a recent article I read concerning empathy.  I am wondering if the main difference has to do with the nuturing ability that mammals have that perhaps vertebrates do not have.  Perhaps mammals are a mixture of nature and nurture, while vertebrates are simply nature.  This makes sense to me when considering emotions such as empathy and how mammals have the ability to foster and encourage certain innate emotions.  Mammals, as a result of a larger brain and a greater capacity for thought, have the ability to construct complex emotions and feelings such as empathy and love and affection, that perhaps vertebrates are mentally ill-equipped to construct.  Just a thought...

I do appreciate our new box labeled the I-function.  Does this I-function = mind?  Or do we normally associate mind as being disembodied or separate from brain?  Is this I-function unique to mammals?  Is it unique to humans?  If the I function box is where the self is created, is the I-function box limited to mammals with self-awareness or are there I-function box variations? I am very interested in exploring this I-function box construction.

sophie b.'s picture

I found the article you

I found the article you posted extremely interesting, in discussions of "natural law" in relation to morality,  we often believe that overarching societal beliefs come out of necessity (if we don't believe it is morally wrong to kill, we can never reproduce our own society, etc)- so it seems rather remarkable that a moral interest in other humans would occur naturally as the article described (infants who whimper after hearing other infants cry). It seems that this would support the Emily Dickinson idea of the brain, if even morality is an organic, partially untrained trait.

cschoonover's picture

The I-function

 I found the idea of an I-function to be extremely intriguing. When contrasting this with the boxes in the nervous system we explained that unlike these boxes, which in large numbers affect behavior, the I-function is not necessary for behavior. If we define it as the “me” box, something that is conceived and experienced by oneself and not the outside world, what then is its role in the nervous system? The example of Christopher Reeve’s accident and ensuing diagnosis was helpful in exploring this idea. Since his nervous system was interrupted in a particular location, he lost the ability to control his limbs on his own; however, he could still respond to stimuli to his nerves. This exemplifies the notion of the I-function if the I-function is understood to be a box that can influence an output by generating an input. The catch is that it is dependent upon other boxes for access to the input. To me this implies that it is intricately connected with the other boxes of the nervous system, thus indicating it is a part of the nervous system. But where is it located? In Christopher’s Reeve’s case, there is evidence that it could be located in the brain and was rendered inactive since his cables were not linked. However, I am still not sure if this is the location of the I-function.

On a somewhat related note, I would like to further explore the meaning of pain. At the end of our discussion we mentioned that one does not have to have previous experience of pain in order to feel it. If this is true, does that mean it is an innate feeling? And if so, how do we explain the varying experiences of pain held by different people? In the case of Christopher Reeve’s, he could not feel pain because his cables were not linked and he was located on the other side of the cables. With this in mind, I wonder if pain is a part of the I-function box. This is an area that I hope we continue to discuss in the coming classes.

yml's picture

differences and similarities in brain

I found this week’s class’s topic about all brains are somewhat the same and somewhat different very interesting. It seems like very logical explanation about the brain, yet I did not think about brains in this way until discussed in the class. Of course, I always thought that human’s and cat’s  (for example) brains would be different. Yes, they can both make sound, therefore they have some similarity in the brain for that function! Then it got more interesting, how about different individuals in same species? So we talked about differences in brains between men and women. Although people often assumed there would be difference between men and women, this is only from the statistical point of view and it, in fact, is found that there is no specific differences between men and women. I have a question about this. What does it mean by only statistical differences? Because in the studies that I’m familiar with, mostly psychology, we cannot test a hypothesis on every single person in the earth, therefore we select samples to represent the whole population. And when there is statistical difference above certain level, we assume that this is true and can be applied to the large population. Therefore, I’m not really sure why we can’t say there is difference between brains of men and women.

Another question I have is are similarities and differences in brains directly proportional to how similar and different their functions are? For example, if one is more similar with my father than with my mother, will one’s brain be more similar to one’s father’s to one’s mother? How about in the case of identical twins? There are many differences between identical twins, how they think, act, etc. However, there DNAs are same and physical features are often very similar. Then how about the brains?


dvergara's picture

I-function a.k.a the Self?

The Christopher Reeves example used in class helped to distinguish (for me) those actions controlled by the brain, and reflexes controlled by the stimulation of nerves. It helped me understand that for a neuron to fire, causing a nerve to send signals to muscles, no pre-approval from the brain is needed; it is simply a reflex. This is much the same way someone can be in a vegetative state yet they continue to breathe and their heart continues to beat. However, why is it that if I want to move my toe, I can, without the need of any external, physical stimulus? This is where the I-function comes into play. In class, the I-function was vaguely defined as a 'box' within the brain that can send inputs to different parts of the body, thus controlling the output. (Example, I 'tell' myself that I want to move my toe and then I move my toe). However, in order for the I-function to work, it must be connected to the rest of the nervous system, I think these cables are found in or near the brain stem. I would not be able to move my toe, if I was not connected to the rest of my body, such as Christopher Reeves.

This all seems fairly easy to understand, but I still do not understand why we seem to equate the I-function with the "Self." From a biological perspective, are they necessarily the same thing? Dogs for example, are classified as not aware of the "Self," so do they not have an I-function? Could a dog not move it's paw because it wanted to do so? In class, I felt we were using the I-function and the Self as synonymous terms when they might not have to be. Perhaps a better example is young children, babies are also classified as not being self-aware, yet I am quite certain a 12 month old child will perform certain actions simply because he/she wants to. So, do we always have an I-function through which the "self" eventually develops, or are they two different things ? To conclude, perhaps our definitions of the I-function and of the 'self' are yet too limited to portray the reality behind the terms.

molivares's picture

New DSM-5

My post is completely unrelated to last week’s discussion. Instead, I want to comment on a recent New York Times article called Revising Book on Disorders of the Mind about changes made to the Diagnostic and Statistical Manual of Mental Disorders (DSM). This article reminded me of the New York Times article we discussed on the first day of class called The Americanization of Mental Illness. While I understand that many the DSM must be updated and must evolve with the development of psychiatry, I find it so appalling that this book single-handedly defines what can and cannot be considered normal and abnormal behavior.  The changes proposed to be made in DSM-5 have been controversial. There are many logistical changes that were proposed involving the labeling and rating of various disorders. “’And it has huge implications for stigma,’ Dr. First continued, ‘because the more disorders you put in, the more people get labels, and the higher the risk that some get inappropriate treatment’” (Carey, NYT February 10 2010). I thought that this quotation in particular resonated with The Americanization of Mental Illness article. While many may believe that by classifying and rating symptoms of mental disorder makes diagnosis clearer and more uniform across the patient spectrum, is it really the most useful tactic in evaluating a patient? In all our discussion about how brains are somewhat the same, somewhat different, how can we possibly quantify and qualify mental illness according to one standard book?

mcchen's picture


 I feel that the notion "all brains are 'somewhat the same, somewhat different'" is very logical.  Brains of humans and animals act similarly in that they keep us breathing and our blood flowing but humans have the ability to express emotion to each other while there is an ongoing debate on animal feelings.  While I am a bit unsure about the I-function, it allows us to locate the "person" in the case of someone like Christopher Reeves.  I feel that the I-function gets rather complicated when applied to patients in a vegetative state because how are we supposed to detect whether or not they know where their presence lies.  For people without Christopher Reeves' condition, does this mean the I-function lies in our brain? Or is it throughout our body because we are aware of all the parts of our bodies and are experiencing them?  What confuses me is how we talked about the fact that an I-function is not necessary for behavior, so does this mean the I-function lies in a separate compartment than the rest of the nervous system?

meroberts's picture


I think it makes sense that there is an "I-function" in the equation of inputs and outputs. How else are outputs generated without inputs? Similarly, inputs can be generally disregarded and fail to produce a response, or output. In this sense, the "I-function" serves as a catch-all explanation that corroborates the Harvard Law of Animal Behavior. In the case of the nature vs. nurture debate, the "I-function" explains the variability in outputs regardless of genetic make-up or environmental factors. For example, we can apply the "I-function" to the case of identical twins who were raised in the same environment during the same time frame but perhaps exhibit completely different personality traits or behaviors. This could be explained by the "I-function". Even though these twins share the same genetic material and were raised in the same environment, they are each unique because of the "I-function". Each twin has their own separate thought processes, value systems, and beliefs. These different values and beliefs can be directly attributed to the "I-function", or each twin's own ability to integrate information and formulate an "output". From my own viewpoint, their individual thoughts and beliefs should be considered outputs to the same extent that physical actions are deemed worthy of the "output" label.

AndyMittelman's picture

Grandma and the tree


            On Thursday we discussed the notion that when you see something/someone you recognize, there is a pattern of activity across inputs. In other words, the same input activity would be involved in recognizing your grandmother and in recognizing a tree. I find this to be a very interesting concept. This logic would suggest there is an element of “pattern matching” we undergo. Specifically, when we see a familiar object, we (specifically what, I’m not sure!) matches the incoming inputs to a previously encountered pattern of inputs. In other words, we intake “A” and realize that “A” seems familiar to a previously received “A.”

            This makes me wonder about the mechanism of actual pattern matching. Do we all pattern-match at the same speed? Could this explain why some people are very adept at remembering names/faces/people while others really struggle with it? If someone has a super fast ability to access those memories of previous inputs, they will recall the similar “A” pattern quickly and be able to rapidly identify the familiar circumstances. I am curious to learn more about this, especially if the circumstances involve multiple senses (eg a smell/sound composition or sight/smell). I have heard that people’s sense of smell and sound most rapidly bring back memories, is this because those pathways are easier to recall?

            To build on this, what happens if the inputs are similar, but not the same. Say you encounter input A’, a similar but different set of inputs to the original pattern. Again, I would imagine that some people would quickly identify this as a hybridized version or the original, while others might not notice it at all or identify it as A. (This might explain why some people are so good at noticing when someone gets a haircut or slightly modifies their appearance). As we go forward I’m curious to learn more about memory and how we recall previous experiences. I hope everyone is having a good time with their web papers!

kdilliplan's picture

Is an I-function really necessary?

 I am not yet sure how I feel about the I-function idea.  I think there is an important distinction to be made between actions that are voluntary and actions that are involuntarily, but I don’t think an I-function is the way to go about it.  I also think there is a difference between involuntary actions like digestion or heartbeats and lack of control over actions like in the case of paralysis or alien hand syndrome.  I consider my digestive process and my heartbeat to be part of me, even though I don’t have direct willful control over them.  I was thinking about breathing as well.  When I’m not thinking about breathing, I breathe involuntarily.  When I am thinking about breathing, I can breathe manually.  And now that you’re reading this, you’re breathing manually as well.  Does this mean that breathing sometimes falls under the I-function and sometimes doesn’t?  Or does it mean that breathing is connected to more than one part of the nervous system?  What else is connected to more than one part of the nervous system?  What is the evolutionary advantage of having functions hooked up to multiple control centers?  Do other animals with brains have I-functions, even if we as humans don’t generally think they have a sense of self? 

I also think that involuntary movements such as what would happen were someone to pinch Christopher Reeve’s toe can be explained without having to resort to a concept like the I-function.  I think it’s adequate enough to say that not all outputs are the result of an input being processed by the brain.  We seem to be choosing to use the term “the brain” to refer to the whole nervous system in some cases and as a section of the nervous system in other cases.  I wonder if the issue of what is and is not governed by the brain might be cleared up by being more careful how we define the brain.

Saba Ashraf's picture

Brain and behavior

            I found it very interesting when we had talked about the brains being different amongst different organisms based on their behavior. I wouldn’t have expected the brains of all cats to be different based on the fact that they looked the same, which is not always a valid way of thinking. Then, when we talked about the difference between men and women, most of the class responded that there was a difference between them initially. When we further discussed this issue, it became apparent that there really was no specific difference between women and men, but there was a difference in a statistical point of view. We came to an understanding that the population distinction is unlike the individual distinction. For example, what all women are said to behave like can be what one man behaves like. I think I found this so interesting because usually men and women are characterized to behave so differently without any exceptions, so I would have expected there to be some difference in their brains. Another example that was used in the class that I found amusing was that some fish are able to change from female to male or vice versa depending on the social situations. This change in behavior resorts to a chance in the brain in a moment of days. Thus, in general all changes in behavior relate to changes in the brain.   

            I also agree with many of the other people when they say that the Christopher Reeve example was very helpful in understanding the behavior of neurons and the brain. I didn’t think that his foot would withdraw after being pinched, but rather it would stay still. If Christopher Reeve was told to move his leg, then the information would go to his brain, but there would be no cables linking to the motor neurons causing no movement.   

Jeanette Bates's picture

The Line between "Us" and "Not Us"

             Though I think that I understand the principle definition of the “I-factor,” I am a bit confused about where the line lies between the part that is “us” and the part that is not “us.” From what I gathered, the parts of the body that we can control, along with our thoughts, are all apart of the “I-factor.” It is also the “experience of self.” What we can’t control or “experience as our self” is not apart of this factor. Our heartbeat, for example. This is why Christopher Reeve’s “I-factor” was considered to be the neck and above-he couldn’t control or experience his limbs, so they weren’t considered to be “him.” This definition may work most of the time, but I consider it to be rather fuzzy. The brain is a very powerful organism, and sometimes the thoughts that we have can influence the rest of our body. Two things that I am specifically thinking about are the placebo effect and false pregnancies.  

            People that undergo the placebo effect are people that are convinced that they are recovering from a sickness, or something along those lines, and because they think that they are recovering, they do. Women undergoing false pregnancies believe that they are pregnant even when they are not, and as a result, they begin to show signs of pregnancy, such as producing milk. In both cases this is not a fully conscious decision, but never the less, the people are thinking, and that thinking is influencing things in their bodies that is supposed to be beyond control. It would seem ridiculous for a woman to tell herself to produce signs of pregnancy if she’s not pregnant, and yet, if she is truly convinced that she is pregnant, even if she is not, she will produce these signs. Her thoughts do this, and I am assuming that thoughts are a part of the “I-factor” since it is our thoughts that give us perception and an “experience of self.” If someone truly believes that she is pregnant, then her “experience of self” becomes “I am pregnant,” whether or not it is true. And it may be true that false pregnancy symptoms and symptoms of the placebo effect cannot be controlled as easily as arms or legs, but it seems to me that they are still controlled because human thoughts create them. My way of thinking is this: we control thoughts and thoughts are a part of the “I-factor.” If we can control what we think, and our thinking causes change in the body, then we controlled that change. And, if something that can be changed, and seen as a part of the self, is a part of the “I-factor,” then would that mean that whatever is involved in these processes is a part of that factor? This is why I am confused. Generally we can’t control these things, so they aren't us. But sometimes we can control them-even if we don’t recognize it. Are they a part of the factor only sometimes? Or is the “I-factor” completely exclusive to only things that we absolutely know we are controlling when we are controlling them? So, what is the “I-factor” exactly?

lfrontino's picture

Brain Variations

 Going back to Tuesday's class, I was especially interested in the idea that there is no actual human brain. Thinking about it, this idea actually makes perfect sense. Because there is so much variation amongst each of our brains, there can be no actual brain prototype which stipulates the characteristics of a human brain. Emily Dickinson's idea of the brain as encompassing all is supported by the fact that there is so much variation between individual human brains.

I also found the conversation about differences in male vs. female brains to be particularly intriguing. It is interesting that we are always taught of differences between males and females as strictly on a population-scale basis, one which cannot possibly account for all men and women, and which is thus still a stereotype. It puts an entirely new perspective on gender for me. What does it actually mean to be a male or a female if no biological or neurological traits can indefinitely be placed with one sex over the other. How is it possible to group genders into only two categories? 

MEL's picture

The I-function


This week I found our discussion about the “I-function” very interesting. I think this idea fits into our model of the brain and it makes a lot of sense to me. The example about Christopher Reeves was very insightful to me and I think it demonstrates the idea of the “I-function” very well. Although Reeves' limbs still reacted to stimuli due to the sensory and motor neurons at the caudal end of the spinal cord, he couldn’t control his limbs himself. It seems extreme to say that Reeves (what contains him) was only located above his neck, but when taking the “I-function” into consideration, it makes perfect sense. How can anything below Reeves’ neck be him if he can’t control it? I also found the example involving autonomic functions very interesting. I had never thought about what separates autonomic functions from voluntary functions. It seems that the “I-function” is what separates them.   


aeraeber's picture

Patterns as Behavior

The idea that behaviors are not ouputs, but actually a pattern of activity across lots of output elements makes a lot of sense in my opinion because behaviors are complex, if each possible behavior was connected to a unique output, the number of outputs would be enormous.Also, many behaviors, especially in humans, are not static, they change in response to circumstances. If behaviors were tied to specific outputs, how would they change? Building new outputs in order to change behaviors would be overly complicated. Patterns can easily be changed by substituting in different framework.

The "I-function" is an interesting idea. Certainly there are parts of the brain that can't be consciously controlled, and that more goes on in our brains than we are aware of, but it seems strange to put the concept of self in a box and separate it from the rest of the brain. I'm having trouble getting used to the idea that part of my brain isn't me. I wonder if it is a "box" in a sense that we might one day be able to pinpoint the part(s) of the brain that is the "I-function?" Or is it simply another way to explain consciousness? Do actions that we are conscious of involve neurons that are part of the "I-function?" Maybe the "I-function" is the part of the brain is different between individuals, and the parts of the brain that we are not aware of are the same. Though, how would we be able to tell if those other boxes were different, if we aren't consciously aware of their actions. Are the the ways that the neurons are connected different between individuals? Or is it the signals they send and times they send those signals that are different? 


Lauren McD's picture

Christopher Reeves

I think the most interesting topic that we discussed last week was the example of Christopher Reeves. It was helpful to understand the symptoms of a parapalegic as almost a blockage within the nervous system. Signals released from the brain cannot travel to the rest of the body, and signals applied to the body are not recieved by the brain. However, the interesting aspect of this is that his foot would withdraw if pinched. Even though the brain cannot interpret the pinching as pain, the foot can still act on its own. It's scary to imagine a world in which we are physically connected to our bodies, but not mentally. Disruptions in the nervous system, while obviously traumatizing for the individuals, allow us to further explore the inner workings of the interactions within our bodies.

gloudon's picture

Christopher Reeve

After talking about Christopher Reeve in class, I decided to look him up.  Within the first paragraph of a Time magazine article, I found out that Reeve relied on a ventilator to breath.  As far as I know, the brain stem controls breathing.  However, Reeve's injury is between the first and second vertebrae.  This makes no sense to me.  I thought that because Reeve's brain stem was above C2 vertebrae, he should retain the ability to breath.  I guess I thought that breathing was controlled by the autonomic nervous system.  If his heart was still able to beat and he was conscious, then how could he not breath on his own?  I found another article saying that after intensive respiratory therapy, Reeve was able to breath on his own for about 30 minutes.  If he required a ventilator the rest of the time, and could not control his body below his injury, then how was this possible?  How can you train part of the body controlled by the brain and not yourself to do something?

mcurrie's picture


 The I function is a very interesting box to think about and since Christopher Reeve could not feel pain or control any movement of his lower body that his person was only in his brain. I know this may seem a easy question but if we have an I function that is what we control and how we experience things what about the rest of our bodies functions. What box controls them? I know the heart beats due to the SA and AV node but how was this function started. I know there are section of the brain that control the functions, would we name these the Not I box, the independent box, the uncontrollable box. Knowing that there are these things we can't control and that any moment this box could shut down or something could occur that makes you lose a function that you take for granted scars me. I like to be in control. But maybe it is a good thing I am not in control of my breathing, heart beat/blood flow, etc. because then I would be too busy trying to make sure I stay alive. In class we all tried to stop our hearts but what about when we're scared and our heartbeat increases, is this increase in heart rate because of the I function or is it just a part of the other box or are they connected by certain cables that the I function can use to manipulate the other box. I guess I'm just trying to sort out what is part of the I function and what is not. Trying to figure what I can and can't control and how these functions are connected to the nervous system and place them in a box. 

emily's picture

I-function and Pain

If a sensation or a motion is caused by a pattern of activity across lots of output and input elements, does the "I-function" idea mean that our consciousness and self-awareness, "actions" of our mind are products of a pattern of activity across lots of output and input elements too? That there is a web of neuronal connections all relating to how we see ourselves that can be grouped together into a "box" called the I-function? What does that mean? Are all of our thoughts and feelings connected? I guess I still need some clarification.

One thing I thought was very interesting in class today was the idea that pain is a function of our brain. If pain is something our brain tells us we feel, are there ways we can tell our brain to not feel pain? Obviously some drugs can do this, but what about some sort of meditation, mental state sort of thing?I have had a sports injury for the past year and a half and it has more or less not gotten better at all. If there was a way to tell my brain not to feel pain, I would be able to play pain free! But, to be clear, I would not be healed. Pain is my brain telling me something is wrong with my body, so being able to block out those signals could do more harm than good. On another note, if there are rare cases of people in vegetative states where there is evidence of an active I-function, does this mean these people can feel pain?


aeraeber's picture


Your post reminded me of a newspaper article I had read about CIPA, a rare genetic disorder. People with this condition do not feel pain, but they can feel touch.( Most children with this disorder die before they are 3 years old, because they don't notice when they get hurt, and so can harm themselves severely on accident. This is certainly good evidence for the idea that pain is a function of the nervous system, since CIPA is a nervous system disorder.