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An ongoing conversation on brain and behavior, associated with Biology 202, spring, 1999, at Bryn Mawr College. Student responses to weekly lecture/discussions. A suggested topic was provided, but students were free to write about any other observations, ideas, or questions that particularly interested them.
So ... after another week talking about the sensory side of the nervous system, what does all this have to say about the "picture in your head"? about "reality" and the human perception/conception of it?
This disagreement of opinions on certain shades of bluish-purple has persisted throughout my life, with other, similar instances happening later. I believe that someone mentioned a similar phenomenon in class this week, asking if we could attribute personal visual differences to individually unique characteristics of photopigments, but I found it interesting to pursue in the forum.
Looking at the photopigment sensitivity curves, it is easy to see that the exact shape and peak of each curve could vary for different individuals, since there is plenty of room for diversity. However, what is interesting is that a slight modification in one or more of the photopigments can give a person a completely different sense of physical reality, at least for certain objects, which in my case, is a bluish purple color. Therefore, we have to take into account the fact that all individuals view the world somewhat differently. With this in mind, I wonder if it is possible to come up with a conception of physical reality if everyone has a different perspective.
In addition, one side note about the differences between the pictures on our retinas and the pictures in our heads. We have extensively talked about visual cues, and how they allow us to perceive the world in three dimensions. Using this, I have tried to formulate a hypothesis about the location of the picture in our heads, but have not yet had any profound thoughts about its existence or its location. Therefore, I anxiously await Tuesday's class when we attempt to physically locate the picture in our heads.
The other thing I was thinking about concerns color. I am amazed that color is not real, yet we attach it to so many things. In chemistry last week, we made a compound. We could tell that it was a certain compound rather than another compound because of its color. But, color isn't real, so what does this mean? Why aren't we colorblind?
As I am sure we all agree, reality is an awareness of anything, given the way in which our senses perceive the world. One person's reality is different from another person's reality because every individual has slightly different perceptive abilities and experiences. Because every person is in a sense trapped in his/her own interpretation of the outside world, one can easily assume that everyone's reality is the same as his/hers. Two individuals will most often encounter conflicting realities when relating to each other. If two people have a misunderstanding, for example, one can reason that a source of misunderstanding is that the two peoples' sense of reality is different.
This discrepancy in senses of reality raises the point that reality is a kind of truth for the individual. So like someone mentioned earlier, if one person sees purple, but everyone else sees blue, that person will BELIEVE that the color he/she sees is the true color. This sense of truth for the individual may be manifested as opinion. If you talk to someone from a culture different from yours, you will realize that your senses of what is true will be different, mostly likely the two people will disagree on which cultural opinion is correct. As you will find, these differences are not easily resolved even by discussion.
Truth, however, is separate from reality, although most people think that "matters of fact" must have correspondance with the natural world, or at least coherence with other perceptions, in order to be "true." While we cannot entirely trust our sense experience, we can accept that it, along with what we know about vision's limitations, can combine to forge a plausible idea about the world that up until the present has not been refuted. I still believe that there is an absolute truth that we may someday get right, in whatever form we know it. The question is whether we will know it to be true and if we will be justified in believing our true inference to be true. Perhaps through conversation, experimentation, and reflection, we as a community of engaged learners can synthesize a socially accepted view that conforms to reality, always keeping alive the possibility of error and the possibility of changes in the way we interpret what is g
We have spoken extensively about vision, but now I find myself curious about my other senses and how they contribute to my reality. I say "my" senses and "my" reality because more and more I am beginning to think that we may all experience differently this world we live in. I am also intrigued by the idea that whether or not humans are able to see there will always be electromagnetic radiation. How does this play out with our other senses?
Considering the artificiality of color, one also has to wonder whether if some of our other senses are making things up too. What is sound exactly? How do our ears and then our brain make up sound? Taste? If we weren't able to hear the "sounds" then would they still be here? Maybe not- the waves that create "sound" in our head would be, but the "sound" is a product of our ears and brain and how they translate the air waves. Perhaps sounds differ among people as color sometimes does?
The reality of what our senses of hearing, smell etc. are actually telling us about the world seem as vague to me as our sense of sight (particularly in terms of seeing color). The term "senses" then seems very appropriate- they do give us a "sense" of what is going on around us- enough so we are able to survive and carry on. What more do we need to know? (everything...I know)
What exactly is reality, does anybody truly know what is or isn't real? Do we want to know? I recently heard reviews for the movie "Matrix" which in my understanding asks the same question. It appears that in the movie machines or something else runs peoples' lives, and it is up to the hero to find the truth. Are we just pieces in someone/something's little game. I doubt we will ever know, but that doesn't stop us from searching.
Now, about the whole picture in your head thing. It seems obvious (or not) that we are not seeing something in the physical world but then why is the picture in our heads three dimensional. What are we actually seeing? Can we imagine things in 3-D? Also I have this question that has bothered me for a long time. When we shut our eyes are we seeing black or nothing at all? Does a blind person "see" black and if so are they aware of seeing such a color (or lack there of)?
Again, answering these questions must seem like an impossible feat, but there is a way one can test what a blind person sees. This is by taking someone who just recently lost his or her sight and investigating what they "see" in relation to what they saw prior to losing their own vision. Unfortunately I can not come up with a way to test any of the other questions I posed.
I believe that the pictures in one’s head are not in just one place because perceptions exist in many physical locations and forms within the brain and body. Pictures come into a person’s head and or are generated in one’s mind by more than one mechanism. Aside from the pictures enter our eyes, fall on our retinas and are conducted to our brains by way of the optic nerve, some pictures are stored in our brains (memories), some completed in our brains (blind spot) and others originate in our brains (dreams). And senses other than our eyes can generate pictures in our brains. Music, words and other sounds are often perceived as pictures in people’s minds. And those images that enter our minds in one form are often translated, stored and recalled in a different form from which they were originally perceived. For example a message communicated in a language from childhood that is no longer understood may be remembered clearly as images. Or dreams that make it to consciousness must first be translated from images to thoughts and language in order to be stored as memories. A story may enter a person’s mind by way of symbols translated into words that are seen and not heard and then may be stored as pictures.
Perceptions of sounds, visual images and smells also often can trigger motor responses other than in the eyes, ears or nose. The sound of a baby crying can start breastmilk of the mother to flow. And the smell of a lover can trigger arousal. Or the aroma of favorite foods can create full-blown visual images of past events creating a sense of calm or comfort. Or a fear response could be caused by any of the senses. These types of things perceived in the present or in the past (as memories) or even as dreams all are capable of producing within the body the associated physical responses. Are these physical responses any less “real” if they if they occur because of a memory or during a dream rather than when caused by something in physical proximity in “the now?”
And in addition to how the brain often edits, modifies or limits perceptions,
sometimes the I function will not be able to accept that which the person
perceives. Sometimes a perception will not fit the widely accepted
consensus, which may vary by culture. Or a perception may trigger memories
too painful to recall and thus the person may be unable to accept such.
Or that which is perceived is incongruous with an individual’s experience
and or beliefs. Again, are the “things,” that comprise perceptions
that are not consciously accepted or processed, any less real?
As for the picture in the head, I have been thinking about where in the brain it might be located. In light of the many different types of specific disorders of visual processing which result from various types of brain injury and the different locations of the brain which seem to be implicated in each, I am inclined to think that the picture in the head may not be all that localized at all. It seems that the information from the retina must be somewhat dispersed to different regions of the brain in order for it to be interpreted and for the picture to be complete. Having written my last web paper in part on blindsight and the neural pathways which allow these patients to retain the ability to process visual input in the absence of visual awareness, I was wondering whether the picture in the head refers to the conscious awareness of the input or the processing of the input. From what I know about blindsight, it is thought that the ability to process and make use of unseen visual input may be mediated by a secondary neuronal pathway which branches from the optic nerve, bypasses the main reception site for normal vision – the V1 area of the primary visual cortex - and extends instead to an area of the midbrain known as the super colliculus. This might suggest that the awareness of the picture in the head is mediated by the primary visual cortex but that the information about the picture in the head is processed by deeper structures. I don’t know if this helps at all, but I just thought that it might add an interesting dimension to the discussion.
In discussing the implications of the 'inaccuracy' of our senses, (or their tendency to fabricate certain perceptions to offer a coherent interpretation) the idea of reality was called into question. As it was mentioned, 'reality' as we perceive it seems to be dictated by the sum total of all the perceptions made over time by society as a whole. That is to say, reality is a notion that is agreed upon by the masses. If everyone perceived something different when viewing a rock, I am sure there would be many varying 'realities'-i.e. there would be no uniform or unitary reality. As it is, every individual's brain seems to possess a similar process or mode of fabrication (assuming there is no pathology involved, like schizophrenia), so that the final image or idea is somewhat similar across many individuals. This is in part due to the fact that most of us have the same 'machinery' or 'tools' with which to view the world.
In terms of whether or not this is an 'absolute' reality is uncertain-or better yet, it is certain that what we perceive is not an absolute reality. Within our society and the constructs by which our society is run,this reality is absolute for all practical purposes. Consideration or interest in living by any other reality would prove not only confusing but also impractical, especially since we cannot directly relate to the other possible realities. But we have some idea that there are alternative realities. The reality for another animal, for example, may in fact be very different as it has been established that certain creatures have transducers for (are sensitive to) different spectrums of electromagnetic radiation. However, even with this in mind, I think that across species, there must be some underlying similarity or constancy in what is actually there, or what is perceived to exist. So, what exists is constant, and it is only a matter of how these objects are viewed that dictates one particular 'reality'. There is a molecule, but every creature may see the molecule (or not see it at all, as the case may be) in a different way. [Is not seeing a way of seeing, or at least a part of 'seeing'?] This seems important to remember, especially since it has been realized (many times over by the scientific endeavor) that just because we do not 'sense' (smell, feel, hear, etc.) something does not mean it does not exist. So I guess, in a way our instantaneous reality is limited by the capability of our transducers. Other attempts to view our 'reality' as a novel or malleable entity (to get a glimps of some underlying absolute reality?) seems to involve looking beyond the senses, either by way of imagination or by way of technological advances (or more accurately, a combination of the two?)?
sorry for all of the parenthetical comments...
“Fact is after all a kind if mind reading” - Sarah Orne Jewett (1849-1909)
Reading Professor Grobstein’s From Genomes to Dreams, made me further think about reality. In this article three factors that influence behavior are mentioned: genome, experiences, and the stuff that your brain makes up due to the other two. It is this last part that particularly interested me, especially its manifestation in dreams. The fact that each of us has “the ability to make for [ourselves] experiences no one else has ever had and hence to see things no one has ever seen and to learn things no one else has ever learned” is an amazing thing. What perplexes me most is how and why the “elements” (experiences as well as genetic information) come together in the “odd” and not so odd ways ( I mean as explained by the psychiatrists who see dreams as a way to your brain !) in dreams.
People often say that behind dreams lies the “true reality.” They often interpret dreams and there are many books written on the meaning of various dreams. Thinking about perception and how unique the “elements” manifested in our dreams really are, makes me think that all those books and efforts especially on the parts of psychiatrists to unravel the mysteries behind the dreams of their patients, are quite fruitless. Fact, that is the reality as perceived by an individual, is indeed a kind of brain reading. The brains of two individuals have to be different in ways shaped by the genome and experience. This leads to quite an interesting conclusion that fact is determined by each person’s brain and if the brains of the two people are different (and I believe that they are or we would all respond in similar ways to the same stimuli) we wind up with different “facts” of reality!?
I want to end with a quote from “A House Made of Dawn,” that came back to me as I was thinking about this. It goes something like this: “Somewhere if one can see it, there is neither nothing nor anything, and there, just there, there is the last reality"
One's concept of reality is something that brings people a great deal of comfort and security. It is when someone loses touch with reality that they begin to think that they are going insane, or rather when their reality differs too greatly from the accepted norm. But how can we find such comfort and solace in a reality that each person makes up? If we are all "making up" the pictures in our head…. color… definite shapes…. How can we tell what is truly real? The thought that what one believes to be real is not truly an accurate reflection of what is out there is extremely disconcerting.
When you really start to think about it all of this "creating" or "making up" makes sense in this world that we live in. Things like color and seeing definite edges allows us to distinguish between things that we would not otherwise be able to define. It increases the amount of information that we can process and use in a productive way to better our chances of survival. It has adapted to suit life on this planet because of the way that it has been created.
Even with this rationalization, it is difficult to comprehend the abilities and functions of our minds. There is an incredible margin of error in this type of processing. Because each person has a different brain, they all process information differently and therefore all have a different picture of reality in their heads. It is interesting to think about the discrimination that this causes. People who see things differently are shunned from society and thought to be crazy. But his shunning generally causes a breakdown in all of their beliefs and even of their morals. Is this why people become insane? I'd like to further explore insanity and it's causes. It seems very interesting and very related to what we are talking about.
So an important question, for me is, is reality set by society or by an individual? As Rachel said in her posting, there seem to be so many "fact of reality". But who defines those facts? It seems like society would lay down the framework of what is socially acceptable to think, but it would be left up to each individual's brain to perceive each situation as they did. True, unless you are a child, it is not socially acceptable to believe that the world is flat, but that didn't stop philosophers and intellectuals from believing that many centuries ago. If that is how your brain perceives that piece of reality so be it. I guess I am sticking with the idea that we create our own reality. And if brain does equal behavior, then each of our realities will be slightly different and maybe the thing that ties one reality to another is the "norm", the "majority", the socially accepted reality.
The suggestion of "true reality" and/or an "individual's reality" would seem to me difficult to conceive. Reality is merely a social construct which provides the frame work to which the 'sane' conform their perceptions and to which the 'insane', by choice or without the benifit of choice, do not.
Human perception is a lie. And the supposed pictures in our head -- no more than a mere splattering of paint (black and white no less). Soiled by the foot prints of the mind we see everything and nothing -- and all that one deems reality -- with the clarity of one's vision through an opaque disc.
For now we see through a glass, darkly; but then face to face:
now I know in part; but then shall I know...
- I Corinthians, Chapter: 13, verse12
It is appealing for me to believe in the existence of a "really real" reality underlying and unifying everything I perceive and everything that is imperceptible to me. If this reality could be known, it might explain everything, providing meaning and completion to existence! Many people feel that we can only see small, perhaps grossly distorted fragments of this reality. We assume there is an elephant and that you perceive the elephant’s trunk while I perceive the elephant’s ear, etc. Together we hope to piece together knowledge of the "real" elephant. The more different ways of "seeing" this elephant we have, the better our chances of gaining accurate knowledge of the "real" elephant. If so, the unusual ways in which a creative, or unconventional or "insane" person might see the elephant are valuable. But maybe there is no elephant. Perhaps there is a "trunk" that exists only in your mind and an "ear" that exists only in my mind. What if our individual brains make up "elephant trunks" and "elephant ears"?
We have learned that the brain is very good at making things up. Just for starters, the brain convinces us that we see things in our "blind spot" and it shows us colors that artists and scientists show us and tell us are not "really" there. In "From Genomes to Dreams," Dr Grobstein tells us we have three sources of information about the world: our genome, our life experiences, and our brains. Whether we are dreaming, imagining or thinking, the brain provides us with experiences that are not experiences with the "real" world. The brain makes up experiences for itself – these experiences are a source of information that cannot be obtained from the genome or from life experiences.
With so many individual brains making up so many unique stories about the world and about elephants, I am wondering if we can really assume there IS an elephant out there. Perhaps the reality behind our social construct of reality is that there are in fact no elephants. But then I guess that reality (the reality that there is no reality, just unlimited points of view) would itself be the elephant...
An interesting example of how realities can be completely different is in the case of a researcher named Turnball and his interaction with pygmies in Africa (I think?). These people lived in a world of jungle and forests, where one could not see more than a couple of hundred feet away from you. When Turnball took some of the pygmies away from their home into the plains of Africa, they thought that a herd of buffalo across the plain were insects. In other words, they had no concept of relative size constancy. Their reality was that objects which are "far away" do not look very small because of the environment around them. However, when they were brought to the plains, where great distances could be seen, they could not understand that a distant object which looked very, very tiny could actually be as large as a buffalo. Maybe I'm going out on a limb here, but their brains did not have the ability to "make up" the knowledge that the "insects" were actually buffalo because they had never experienced that kind of input before. However, when our brains "make up" for the blind spot, or interpret colors, it is because the brain has learned to make sense of various familiar inputs.
Another question that is really interesting is the one that Mary brought up. Why is it that we see color if it is not really there? Obviously, it is been some sort of evolutionary necessity, whereas seeing heat as snakes do is not absolutely necessary. I can't help but wonder if people who see "hallucinations" or who are deemed to be relatively insane simply have realities out of the norm which could just as easily be the "true" physical reality.
Another relevant (I hope) question I have is how much of our other senses does the brain make up in order to create reality? Taste, it seems, is something that is very dependent upon other senses in order to fully experience that taste. For example, whenever I have to take horrible tasting medicine, I will hold my nose. Somehow, I believe that not smelling it will help me to not taste it. Isn't this demonstrating how our individual senses do not work alone, but often are integrated together to create a reality? Now we have learned that our brain does not integrate every piece of information from our retina into one central "picture in the brain"... does our brain, however, integrate other types of information to create a central output or experience, though?
On the "what is reality" topic, I agree word for word with Marion's comments. We've found that our brain fills in, throws away, and makes up a lot of things to come up with a sensory manifestation of its surroundings. We have found that there are wavelengths we can't see, and scents we can't smell. I find the notion that reality is what our brains make of it fascinating. But does this really bother me? Not only does it not bother ME, I don't think it really bothers anyone in this class. If it really bothered you guys, you would stay in bed all day, afraid to leave your room for fear that your conception of reality was not necessarily accurate--after all, you might walk in front of an invisible speeding car or fall into a deep invisible chasm on your way to class. But no, for the last 20 years, our conception of reality has proven, time and time again, to be extremely accurate, and extremely close to the conceptions of other people. It is a huge survival advantage to make correct accessments of reality. We are all products of billions of years of nature's trial and error. We wouln't be here if our accessments of reality were wrong. We aren't getting the full picture of what's out there, but we are getting what we need for our own survival purposes. And we're all pretty much the same in the way we see/hear/smell/taste/feel things. Your red is my red is Prof. Grobstein's red, I'll bet! We're all human, and we all have basicly the same genetic makeup. Yes, how we percieve things can be influenced by social constructs. But not the nuts and bolts perception that gets us through the day; tasting, recognizing, judging the height of each increment of a flight of stairs. 99.999354% of that stuff is universal, and not socially influenced.
Humans have a unique form of behavior, one that is mediated by thinking. In order to think and make choices regarding our behavior, we must have a certain conscious experience, namely a picture of the world in our head to which we can react. If photoreceptors merely sent signals which activated certain pattern generators without forming a conscious picture of these integrated signals, we would not be able to "think" about our environment visually. We would probably still be able to find food and avoid predators, but our choices would be based on simple neural pathways and connections which obeyed the harvard law of animal behavior, and we would not be able to reflect on these choices. Instead we are able to rationally choose to alter our behavior (even if the choices do not seem to be the most appropriate based on environmental signals) These rational choices may still be based on neural connections, but since they involve this phenomenon of sensory consciousness which simpler organisms seem to lack, these connections must be incredibly complicated.
This line of thought has implications regarding consciousness which I would like to explore further. What kind of consciousness do animals experience? How does it differ from human conscioussness? Is conscioussness based solely on our phenomological representation of sensory input?
I also am interested, in terms of reality, the notion of a collective conscience. When people are driving on the highway for long periods of time, they tend to space out a bit, even if only for a short moment. During this "spacing out" time, I am curious how everything runs so smoothly with no accidents. There is always a moment when people have been driving for a while and they think back not remembering a certain portion of the trip. Could this be the brain's way of filtering out extraneous information? (a long trip, no need to remember every minute of it...) One explanation could be that the brain was at a sort of "rest." It was functioning but was not including the I-function in it's decision making. It was just "going with the flow?"
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