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An ongoing conversation on brain and behavior, associated with Biology 202, spring, 1998, at Bryn Mawr College. Student responses to weekly lecture/discussions and topics.
Since you last wrote, we're talked about lateral inhibition and color vision, with a focus on the creation of categories by the brain, about blindsight and the issue of whether one needs a "picture in the head" to "see", and about frog orienting behavior and "intrinsic variability". Which of these most affects how you think about the relation between brain and behavior, and why?
I've been reading a couple of passages from the book, Music, the Brain, and Ecstasy. It's a really interesting book. Being a music lover and knowing the knowing the effect music can have on my moods, the author, Robert Jourdain, quickly got my attention. I participate in two choirs, the Bi-co Gospel Choir here and the Youth Gospel Choir at my Church. One of the directors once described singing as healing and becoming of angels. I love Jazz and instrumentals. I don't know how many of you listen to 106.1, there's this piece that they play, I don't know who it is by, but whenever I hear it I automatically stop in my tracks, I close my eyes and as it progresses, I get filled with this amazingly peaceful feeling. At church, we have these really talented musicians whose contribution to the worship has the effect of drawing you in. Last week, in one of my classes, my professor suddenly stopped in her tracks, she quickly recovered, explaining how she had been captured by the beautiful singing of some birds outside from the window. She had this look on her face and all of us were just simply amused.
I am sure you have your own experiences with music. So then it makes to wonder about the connection between music and our brain. How does music so charmingly captivate us and evoke such emotions. Read the book. But I'll share a little of the stuff I found really amazing. He tells about this lady Frances D. who suffers from Parkinson's disease. Parkinson desease is characterized by damage in 'two tiny bundles of neurons at the brain's core'. What results out of this is that the translation from intention in the brain to the actual action of the muscles sometimes fail. It's like the brain is still going through the process of delegating commands, but the body doesn't always follow its commands. It is typical for example for the lady, Frances D. to be walking and all of a sudden stop, unable to continue in her tracks. Jourdain explains how for Frances and many other sufferers like herself, music has this powerful healing effect. He describes, "One minute would see Miss D. compressed, clenched, and blocked, or jerking, ticcing, and jabbering-like a sort of human bomb; the next, with the sound of music from a wireless or a gramophone, the complete disappearance of all these obstrusive-explosive phenomena and their replacement by a blissful ease and flow of movement as Miss D., suddently freed of her automatisms, smilingly "conducted" the music, or rose and danced to it"(p301). He also describes a case where 'just the thought of music could do the job. He explains that, "One patient was able to 'play' whole compositions by Chopin in vivid mental imagery . The moment she began, her grossly abnormal EEG ( her 'brain waves') would abruptly turn normal as her Parkinson's symptoms vanished. Just as abruptly, every symptom would return the moment her clandestine concert drew to a close" (p301). Not only that, but success of the music depends on the taste of the person and their disposition at that particular time. How does one explain this phenomenon.
Jourdain explains this by describing the state of Parkinson's disease as a mismatch between what the brain anticipates to happen and what actually happens. This disharmony is what for example causes a patient to stop dead in their tracks right in the middle of an activity. Music apparently works for these patients because of its nature as a continuous, flowing entity that 'establishes flow in the brain'. This in effect helps the brain by 'bringing its anticipations into step'. I find this really fascinating, so I'll see if I can find more detailed explanations and understandings of how music works on Parkinson's disease.
Fascinating indeed. There are some descriptions in Oliver Sack's Anthropologist on Mars of similar effects of music in other situations, and there is an older symposium volume, Music and the Brain (Critchley, M. and Henson, R.A., eds., London: Heinemann, 1977) which you might want to look at. Can one explain the phenomena of powerful influences of music on behavior? Not at the moment, I don't think. But I think one can come up with several candidate mechanisms that would be testable. Want to take a crack at it. At least one might be related to Ruth Czarnecki's The Neural Score for Language and Related Action. PG
I also recently finished reading this other book by Peter Kosso, entitled, Appearance and reality. So I found the ideas raised in class from tallking about the eyes and the information the brain gathers through them very interesting. Considering these ideas without a doubt sends one wondering about what one sees and the reality of things. About that same time we were discussing the act of seeing in this class, we were struggling over the ideas of Realism and Constructionism in my phylosophy class, trying to see if these two philosophies could be reconciled. In a general sense, Realism can be described as the view that there exist a reality independent of our conceptions or perceptions of it. Constructionism for its part argues that there is no reality independent of our interpretations and conceptualizations. As far as the constructionist sees things, none of us can talk of a 'reality that is' because of our inability to escape our conceptualized practices. At first, I vehemently argued against the constructionist view. What do you mean there is no 'reality' that we can speak of.
I then wrote my paper for that class where I argued against the constructionist, Thomas Khunn's thesis in The Structures of Scientific Revolutions. I cornered my argument on the fact that Kuhnn's writing in numerous instances could not even refrain from positing a 'reality that is'. His constructionist ideas were unquestionably founded on this reality that even he could not keep quiet about. Although Khunn didn't convince me of constructionism, he sharpened my understanding of the dillemma between the two philosophies. It is undeniable true that our perception of the world is conceptualized and theory laden. Realism has a very hard time going around that challenge. I still vehemently resisted the constructionist view, but I then started taking its claim more seriously and the challenged it presensented to the stout realist. Kosso's work then came in the picture. Kosso, describing himself as a 'realistic realist' sought to address these issues by using Physics to argue his Realistic Realism philosophy. He builds his case using the Theory of Relativity and Quantum Mechanics. Read the book, its very thin and very interesting. In light of his ideas and the discussion in class, I came to the realization that realism could not stand on its owm as much as constructionism could not stand on its own. These two philososphies need each other. The constructionist is right that the realist is constrained by her conceptual frames. But at the same time, our conceptual frames can't help being constrained by the reality that is.
Why am telling you all this. Well, just wanted to share my frame of mind in thinking about the issues of what we really see.
No apologies needed. I'm glad our course material intersects well with other things you're thinking about. And they are indeed both closely related and worth thinking about. Clearly the brain is "constructing". But its constructions are constrained by information it gets from sensory input pathways. That matches your argument fairly well, no? And perhaps gives us a basis for suspecting, if not proving, that there is an external reality? PG
That we don't see color based on signals from rods alone says that the experience of color is not inevitable but doesn't, I agree, say that "color does not exist". What the latter is intended to stand for is the idea that there is no fixed correspondence between wavelength and perceived color, that a given color percept may be caused by a particular wavelength of light but can be identically caused by any of a variety of mixes of wavelengths lacking that particular wavelength. Its THAT observation which says that "color" is a brain category, rather than an external reality category. That ok? PG
My most recent web paper was on phantom limbs. A particularly interesting topic regarding phantom limbs is the plasticity of the cortex. Plasticity basically means that when the neurons in the brain are no longer receiving stimulation - as occurs after amputation for example, the neurons will re-organize so that inputs from other areas that are still attached send input to the reorganized neurons. Therefore, when these neurons are stimulated by this sensory input, the person "feels" sensations in areas that are no longer attached to the body.
I was thinking that since the tectum in the eye has a similar role as the cortex in the brain, and therefore receives input from certain areas in the retina, just as the cortex receives input from certain areas in the body, that when damage occurs to the retina, the tectum may re-organize - just as the cortex reorganizes in the brain.
What would happen if this indeed did occur? Well, I can only predict that "phantom sight" or "phantom vision" would commence. Now, I am not sure if this really has been known to happen, but I don't think I would be all tha surprised if it did because inputs from the retina would be sent to a re-organized tectum, that would stimulate areas on the retina that had previously been damaged or destroyed, so sensations of vision would occur. It makes me wonder whether people that become blind later in life have phantom visions and what exactly they "see?"
Do they feel pain in their eyes because their corollary discharge signals are not in sync with their sensory input? This is what occurs in amputees that have phantom pain. . . It would be an interesting topic to explore further.
Interesting, and appropriate set of thoughts, though I'm having a little trouble following you through which areas might reconnect to what, and what the consequences might be. In fact, in some experimental situations it is known that surviving retinal regions DO occupy tectal areas normally occupied by damaged retinal regions. And the upshot might well be that lights at some location (activating surviving retinal regions) might be mislocalized to other places (those which would normally activate the lost retinal regions). I see you suggestion that complete loss of retina might lead to activation by some other inputs, and hence to "phantom visions", but am not sure where you expect your corollary discharge signals to come from. Definitely worth thinking more about. Thanks. PG
It makes the picture we see seem much more three dimensional, not only in how it appears, but also in the fact that different pieces of it are coming from different parts of the brain.
I am especially curious about what the world would look like to someone unable to see motion, who sees in still frames...How does this function and why does it happen?
Intrinsic variability is interesting too, but not as gripping. I accept it as a fact of daily life, whereas considering how I see what my eyes are seeing is stranger. A neurobiologists view on behavior would be interesting to compare to that of, say, an anthropologist or psychologist. Because in the case of a human, we can begin to consider societal influence in behavior. It seems as though that ought to get tricky.
What do we need a psychologist or an anthropologist for? After all, social influences are just action potentials in sensory neurons, no? Yes, of course, a psychologist and an anthropologist would shed extra light on seeing (but why?, those influences really are just what I said above, no?). And, maybe, also on "intrinsic variability", which we have a little more to say about which might make it more interesting. In fact, "intrinsic variability" is probably a part of seeing. PG
And also, just when I was thinking, "Maybe at the end of the semester, Dr. Grobstein is going to say, "Ha! There is no I-function!"", I guess there is. Should the definition of I-function be more finely tuned? In the case of the pleurobranchus, if the I-function is related to "choice", I am tempted to say there may very well be no such thing. Is conscious thought a factor in choice? But in terms of blindsight and being consciously aware, and paraplegics, well, ok, there is an I-function. Very confusing. Maybe I'm not thinking hard enough.
One more thought - completely random - what is it about stereoscopic pictures that makes 3-D illusions visible to those of us who have "normal" vision? I can't seem to tell a shading or color difference on the parts that are supposed to "stick out" - what's up?
I'm not sure, but either there are cues parts of your brain doesn't pick up (as mine doesn't) or parts of your brain are less good at persuading other parts they should be listened to. And I think you're thinking plenty hard enough. No, I'm not going to say "surprise, no I-function". As you say, we've got too many observations to sweep the thing under the rug at this point. Yes, we'll talk a bit about intuitions and gut feelings, and what might be the difference between conscious choice and what Pleurobranchea does. PG
I think that what unsettles me so is the simple realization (that has happened before and will probably happen many times) that we can function pretty well from day to day without knowing or needing to know that we are constructing inside of us so much of what is going on around us. We compensate for blindspots and we compensate for differences in lateral inhibition daily. We incorporate these processes and categories into our routine without even understanding that we are doing it. The implications here (that we understand so little about ourselves and our own processes) are going to take some getting used to. No, I am not comfortable with it, but I am processing it. Knowing how much of what we see in our head is not a true replica of what we are taking in with our eyes is pretty overwhelming. It is, at least, for those of us who have taken it for granted all these years that "what you see is what you get." Not so, Miss Johnson.
Now THAT's what I wanted someone to say. Thanks. To you, and Miss Johnson (the other), for being a foil. Yes, "without even understanding that we are doing it". Until now, of course. Which is a good general principle: we can all learn, and should. Constantly. Not only about what is going on out there but about how we're making sense of what is going on out there. And remember, its not all "compensating" for our failings. There's some clever stuff too that we know how to do without knowing that we know it. Indeed we may know more that we don't know about than that we do know about. That any more appealing? PG
I didn't used to think so, but since getting glasses .... Interestingly, correcting vision with glasses has less to do with the nervous system and more to do with the optics and size/shape of the eye. What glasses do is primarily to sharpen the image on the photoreceptors, before it gets turned into neural signals. And yes, indeed, the evolution of the visual system is a very interesting subject. What makes you think partial decussation would occur later in evolution than complete decussation? And I wonder if its true? PG
Considering the man who could not report seeing a light flashed at specific points in his visual field, but could point quite accurately at this light, a point comes up aboutthe relationship of the brain to behavior and vica versa that was not necessarily too lucid before.
As we discussed the recurrent collaterals and the fact that outputs change inputs and thus may change outputs again, the evidence of blind sigt had not been presented. The evidence from blindsight points out the fact that ouput may be rendered without input ebing detected by the i-function, and output also doe snot have to alter input. Afterall, the person pointing at the light he does not see is not going to change his position to the light to see it better, or such. About the first point, it seems as though blindsight makes the pointing response almoist into a 'reflex'. When the knee jerk was discussed, the dissociation between the leg movement and the I-function was repeatedly stressed. This dissocoation was also used to define the reflex terminology.
Another thing that ties in with the dissociation of the I-function and behavior, but ties together brain and behavior is the frog movement in the frog who leaps forward even though the prey is to it side. The frog may perceive it there, but the brain does not allow for a proper information conveyance. Hence, the frog does not act on what he sees. Again, pointing out the importance of the role of the brain in behavior.
A number of interesting points, with linkages between them that I'm pretty sure are clear in your mind but may be less so to a reader (this one, for example). In what sense, for example, does a frog "not act on what he sees"? What are you imagining to be the frog, as opposed to the actor? as opposed to the seer? In what sense does the "dissociation" "define the reflex terminology"? I like your attention to a "dissociation" between the nervous system acting and the "I-function" (a restricted part of the nervous system) acting, but am less clear about why the blindsight makes the point more "lucid". PG
It is interesting that the fluid and predictable nature of music is what is helpful for relieving the symptoms of Parkinson's disease. My question is, is music inherently predictable? How does the brain actually know what is going to come next in music? It is experience based on listening to a lot of music and knowing what usually comes next or is there some physical aspect to the music that makes the sound waves come in in predicatable frequencies?
One other question is what about music that has a lot of random breaks in it and is totally unharmonic? It seems like a lot of the 20th Century music is more abstract in nature and is not meant to have basic predicatbility in tune. Does this mean that when a Parkinson's Patient listens to this type of music the symptoms do not go away? Or is it any type of music that relieves the symptoms? I should probably read the book . . .
And/or some other ones (see my response to Zermatt's thoughts on music above. Yes, both physical and physiological variables influence how one hears and how predictable it is (see, for example Demonstrations in auditory perception). I like your question about whether what is at issue is music per se, or particular types of music. And, in particular, I'm intrigued by the issue of whether "predictability" makes a difference. My guess is that it does, but there are various kinds of "predictability" in music, no? In my experience, at least, some music is more or less immediately predictable - a sequence of tones makes the next tone predictable - whereas for other kinds of music (including more "modern" music?) one waits longer for the "prediction" to come true? Certainly worth exploring further. PG
No, I don't think you're confusing anything. The basics are, I think, as you describe them. And from them follow exactly the sort of next questions you're asking. Which are being asked to varying degrees in ongoing research in both neuroscience and cognitive science, without yet having clear answers so you might well want to join in. Yes, there is some evidence for at least some neural similarities between the picture in your head when seeing and the picture in your head with eyes closed. But there are almost certainly differences as well. As for how long it takes to "get" a picture? That seems to depend a lot on what it is and what the context is. PG
Last weekend, I was at a the Seven Sisters Tennis Championships at Wellesley College. My partner and I were in the second flight for the doubles draw. The weather is noyousishley bad for 7 sisters tournaments, and this year was no different. Rain on Saturday and snow on Sunday
sent all five teams indoors to Wellesley's beautiful facility. Unfortunately, the indoor courts were extremely fast. So fast, in fact
that a good serve was almost always unreturnable. Anyway, I was noticing
that when I was in the position to return serve, often my racquet would
be back, and my body turned as a bad serve landed in the net. In other words, my preparation was so fast, that I had already tracked the flight of the ball as being either on my forehand or backhand side and was turning in response to this by the time the ball had only traveled 25 feet in the
air. Now, this is not an unremarkable thing among tennis players. All the other players there experienced the same thing. The remarkable thing is the speed of the human nervous system. Our discussions of visual
input and 3-D transformation in class seemed to leave out something.
These discussions seemed to account for only one link of the visual
chain at a time. In fact, our visual system is increadibly complex. Returning a serve in a tennis match involves a series of events and decisions that occur in rapid sucession. First I have to track the ball from my opponents hand as it flies through space, next I have to decide which shot I want to hit (taking into consideration the speed of the ball etc.), then I must have perfect timing to hit the ball with exactly
the right angle and direction.
Hi I'm back.. I accidently hit the post button instead of review for posting...
I wanted to share my experience because I think it illustrates the bigger picture in understanding behavior.
Glad you did. And actually bears on two things. One is the speed of the whole process, as you emphasize. The other is you "noticing" that you had ... . I meant to point this out in class yesterday, when we were talking about whether there were some positive features to not using the "I-function". Most athletes know that for rapid, skilled movements its better if they don't "think about it" and instead "let their body do them". Which is to say, they're better (certainly more quickly) done without the I-function. PG
Its a very interesting and very germane issue. Is there "real" unpredictability (in neurons or elsewhere) or is it simply the case that there are too many variables for us to keep track of? In one sense, it doesn't make any difference: things can be equally mysterious either because we don't know know all the variables and their interactions. In another sense, though, it makes a lot of difference: if there is no "in principle" unpredictability, then every organism's behavior (including our own) is "in principle" predictable, which raises some difficult issues with regard to personal choice and free will. From this perspective, its nice that, as we discussed briefly after class, scientists are increasingly coming to understand that in nature, unlike in the brain, it is randomness and not patterns that come first: things behaving unpredictably is the norm and it is patterns that need to be explained, rather than patterns being the norm with unpredictability needing to be explained. A physicist, Erwin Schrodinger, is the first I know to make this point explicitly, in a wonderful little book called What is Life?. And there are a number of exhibits on Serendip that relate to order from randomness if you'd like to start exploring the matter further. PG
The question on the table is what exactly is the "I" seeing and can we say that perhaps the brain is "smarter" than we are, by integrating images where there are none and convincing us of color that may or may not be universal? I agree, Ms. Johnson (Julia, that is) that this is indeed a very disconcerting thought - one in which the term "blue" is not necessarily an objective thing... Still, we are taught in Physics about waves and optics and certainly about wavelengths belonging to specific colors in a spectrum. So, how can it be that such a clearly conrete thing (with numbers and greek letters letting us know it) is really potentially "all in our mind"?
If, in fact, we can distinguish what the "self" perceives as color from what the "brain" perceivevs as color, then the whole notion of the brain dictating behavior may be less real than previously envisioned. Indeed, one can consider that behavior is purely adaptive to the restraints that a functioning society puts on us..not what our brain would have us perceive. Perhaps our brain sees "magenta" when everyone else is telling us "go - the light is green". So, we adapt and assume the light is green, behaving as if the color discrepancy never existed.
Perhaps we are more in control of our functioning capabilities than necessarily evidenced by such an example, but it is important to consider the potential chasm between brain and behavior when examing such notions as the blindspot or color perception. In the end, the quesiotn still remains, "where is the self?" As Miss Johnson said, "what YOU see is what you get." I am left pondering "Who is the 'YOU' who is getting it?"
Here's again to Miss Johnson (both of them). Can we be sure we have a few points straight? The physicists are "right" about wavelengths, and the relation between wavelength and perceived color, so long as one deals with only a single wavelength at a time. In general, most people perceive a particular wavelength as more or less the same "color". What divorces color from physical "reality" is that exactly the same percept can be achieved by a large number of different mixes of other wavelengths. In this sense, "yellow" is not an aspect of physical reality but rather a category corresponding to a particular pattern of activity in photoreceptors, a category created by the brain.
Now, where is your "whole notion of the brain dictating behavior may be less real than previously envisioned" and "the potential chasm between brain and behavior" coming from? Indeed, the brain is probably "smarter than we are", certainly in the sense that it gives us to perceive something as universal which in fact probably isn't. Remember, though, that (at least insofar as one accepts the brain=behavior idea), the "we" is actually a part of the brain, one which may not know at any given time what the rest of the brain is doing but can in fact find out about it (as we have been doing in class). So maybe its actually "smarter" than the rest of the brain? Yes, we do need to talk more about the "I-function" and its relation to a sense of self. And we will. PG
I know that this is more memory based but I am continually fascinated by the brain's ability to create sensory experiences out of nothing.
We've yet to talk about where visual images come from if not from the eye and optic nerve, and will. In the meanwhile, though, we've laid some useful groundwork, no? A picture in the head is a pattern of activity across various areas of the brain ... so how other than by stimulation of photoreceptors might a pattern of activity arise? PG
Then I thought, aren't the ratios of photopigments in our eyes probably slightly different for each person? So maybe there are no two people with exactly the same way of seeing? Maybe what I think of as "blue" is not what others think of as "blue"? It seems there is no way to test this! Also, since I am very nearsighted and have a lot of astigmatism maybe the picture in my head with my glasses off is also something completely different that I can't really convey to other people? Would this be true for other senses as well?
On Libby's post on tennis, I read somewhere that there are many different types of "intelligence" and that athletes have a special kind of intelligence (I forgot the exact term they used) related to their ability to process visual and other inputs and coordinate them with resulting motor outputs. The brain must be making a number of very complicated calculations to say, know where a ball is and when exactly and in what direction a racket or bat should be swung to hit it. Just because the "I-function" isn't consciously making quantitative calculations like in math class doesn't mean other parts of the brain aren't.
The "blindsight" tests seeming to indicate that the brain is processing visual inputs without them being perceived in the conscious "I-function" reminded me of my "subliminal perception" paper. In it I described some experiments in which subjects reported not observing a visual input but produced outputs relating to it anyway. In the simplest of these experiments (conducted in the 19th century) a flash card with a character printed on it was shown to the subject at a far enough distance away that the subject self-reported not being able to identify the character. However when the subject was forced to guess what the character was the accuracy rate was higher than mere change would predict!
It is very interesting (though a bit scary) how it is hard to be sure whether the picture in our heads actually corresponds with reality.
Does it get any less scarey if one begins with the proposition that "reality" is actually a construction of the brain? In that case, at least, one doesn't have to worry about "whether the picture in our heads actually corresponds with reality". One can, instead, focus on the extent to which the "picture in our heads" helps us in getting food, avoiding stubbing our toes, and so forth. And that it demonstrably does, pretty well, no? Yes, the picture may be (probably is) somewhat different in different people, but its also modifiable, in part by interacting with different people, so maybe the differences are actually an advantage, rather than a disadvantage, since they suggest ways the picture in any given person's head might usefully be modified? PG
I'm with you, in not seeing any reason in what we've talked about to doubt the brain=behavior principle. As long as we keep in mind that "I" is itself a function of the brain. I'm also with you in thinking (still) that the recognition of "construction" by the brain is a pretty big idea, with lots of implications to explore. And, for that matter, I agree that one of the most interesting things that comes out of all this is how and why the I-function is around sometimes and not other times. We'll talk more about this, and maybe even about where it might have come from in the first place. Any ideas? PG
The variability of frog behavior is less interesting because it could possibly be explained using other theories besides the I function. One major problem with the frog variability findings is, it is impossible to actually control all the variables between two given trials so as to make them exactly identical. There will always be a difference between the first and the second trial, even if it is only that in the second trial the subject has a different history. Keeping consistency between trials is made even more difficult when the experimenters cannot be sure what all contributing factors to a behavior are. Perhaps there is a particular neurotransmitter active on the first trial and not active on the second trial; if this NT affects jumping behavior then even if the experiment thinks that the two trials are identical they are not. If we were able to understand and predict all the contingencies with in the organism and the environment down to the sub-atomic level then variability may cease to exist. The question of variability of frog behavior reminds me of an example once given by Prof. Neuman: When a leaf falls from a tree we cannot predict where it lands because we considered its flight path to be random. But if we know everything about the leaf, down to its finest contour, and we knew all about the windís speed and direction we would then be able to predict were the leaf would land which a much higher degree of certainty (this is a pretty rough paraphrasing of a much more eloquent metaphor). It is much the same with behavior, it only seems variable or unpredictable because at any given instance we are unaware of many of the contingencies affecting the organism. Perhaps sciences will never be able to discern all the possible factors that affect a given behavior; every time a new level of intricacy if discovered, there is a new level of variability until there is an box within a box within a box in an infinite regression. As for the picture in the head, it does seem to lead a lot of credence to the notion of an I function. But I wonder how much the picture in the mind is dependent on language. Without languages people would not be able to explain the existence of their internal picture others but also to themselves? Is it possible that what we think of as picture in our mind are images associated with verbalizations going in our private world? In other words do pictures in our minds only exist because we can describe what we are seeing and have seen to ourselves?
Variability as fundamental or ignorance is an interesting issue. As I wrote to Rachel above, there are a variety of reasons to think it may indeed be fundamental (and some reasons to wish it to be so). It is, however, indeed hard (probably impossible) to prove the matter one way or another experimentally (see the end of Variability in Brain Function and Behavior"). Which is, of course, true of most things in science, and leaves one, as always, to instead judge the usefulness of particular concepts in terms of how effectively they raise new and explorable questions.
The relation between the picture in the head and language is an interesting issue. My guess is that the two are relatively independent, since lesions can alter one without substantially affecting the other, since the neural locations probably associated with the picture exist in organisms other than humans, and because, in general, language itself seems to have its origins in-built internal brain processes rather than in experience with the outside world. That's very much a guess, though, with some of the things I'd be inclined to look into to explore the matter further. Very interesting issue, the more so the more I think about it. PG
First, I wanted to bring something up that I had been wondering about. Why aren't the photoreceptors in human eyes located in the outermost layer of the retina, so the axons wouldn't have to pass through any other layers forming the optic nerve, locating the point of our blind spot. Octopus have the same type of lens eye as we have, except theirs are more efficient. Their photoreceptors are located in the outermost layer of the retina, eliminating the blind spot and increasing availability of light to receptors. Perhaps there is a particular reason why our eyes developed this way?
Understanding behavior means that we are able to predict any behavior that will occur under specified situations. We have learned that this is nearly impossible. Even with the most highly controlled experiments, behavior is still unpredictable because there must be other inner boxes that aren't being accounted for.
No one factor affects how I think about the brain and behavior more than the next one. I don't think factors can be looked at separately. I don't think any one, by itself, is sufficient to explain the relationship between brain and behavior. It is possible though, that taken collectively, lateral inhibition, color vision, intrinsic variability, etc. can form a basis upon which to account for some behaviors.
For "some" behaviors? Which ones do you want to hold out, and why? Figuring that out is what can get us more steps along the path. Perhaps "predictablity" is more than just additional boxes that "aren't being accounted for"? As for the human (and other vertebrate) eyes, there probably is a "reason", in the sense that one could describe the sequence of evolutionary stages which led to the current state, but there probably isn't a "reason" in the sense of "something which makes it better to have the photoreceptors in the inner layer". So far as I know, the usual "explanation" is that the photoreceptors derive from epithelial elements which, because of the way the eye cup forms, end up lying on what comes to be the outside. Its an as yet uncorrected (for some reason not correctable?) accident of evolution. PG
very interesting concept regarding blindsight.. i had heard that in patients with severe epilepsy, that severing the connections between the two halves of the brain sometimes suppress the symptoms, but as a result, the patient is unaware of seeing with one eye or the other, thoough is able to identify objects that he did not "see". so if there is no longer a direct connection between the two lobes, how does the information flow?
coming to the picture in the head.. i can grasp the idea that the brain needs several pictures to convert images from a 2-D screen to a 3-D screen, similar in the method of creating a hologram by using several cameras at different angles.. but if the brain has to construct a 3-d image each time it "sees" something.. how does this play a part in memory? when i close my eyes, i can "see" a picture of my house, in the correct dimensions and shapes.. does the brain use the same neural pathways for seeing memories as it does for vision? if not what is the connection? but i am confused on one issue, if there is no picture formed in the brain of what is being presently seen, how can this be compared with what is in the memory? that is assuming that the memory is stored as a single picture, not several different perspectives...
I think that Akino's comments regarding "intelligence" of athletes not being solely measured as to what the I-function is doing is very astute. i can think of many times that the brain is actually computing solutions when the i_function is not working, it happens frequently when trying to remember something, by shifting your attention (i-function?) to something else, you can often remember what you were puzzled by... another example would be waking up with a solution for a problem that you had before you slept.. with this in mind, it is not surprising that the brain can compute without the i-funtion being active.. an area very much interested in by nasa and other space agencies who would love to find methods of putting the conscience to sleep during long space flights but still having the computational abilities of the brain be active.
Hmmm. Lots of interesting ideas/thoughts in here. The relation between the I-function and "personality" is something we'll talk about a bit shortly, but the bottom line is almost certainly that you'd have to transfer more than the I-function to get identical experience/behavior. And yes, blindsight is closely related to split-brain observations, which we'll also talk more about. And yes, it is very true that the I-function is NOT involved in lots of "intelligence", indeed that one sometimes does better without it. Finally, images and memory? Good thought. Would it all make sense if your assumption is wrong? if memory is not "stored as a single picture"? PG
Is seeing being able to describe the colors, shapes and specific distances objects hold in the universe around us? or is seeing somthing simpler, just being able to get from here to there, or point (reliably) at on object, but not really be able to describe it in detail. It seems both phenomenon are seeing, just on different levels. One is conventional, full sensory seeing while, the other is seeing with a substantial handicap.
Being able to point towards and object with out having a picture of it in your head seems that it would require a lot of faith in ones nervous system. To let the I function rest and allow the silent nerverous system to operate. How often do we trust that part of our bodies knowingly, letting our I function really let go and totally rely on the nervous system which does get to ever "hold the floor" in our brains. I don't think I let that happen too often.
At the eye doctor seeing is being able to identify letters on an eye chart. But I think seeing is more than that. For me it is being able to experience the emotion of the scene, to feel the mood around me. In this sense seeing is much more then the picture in my head, it is the words or sounds carried by my ears, it is the touch of other people or the sensation of temperature on my face. As smell is some large percentage of taste, these other sensations are a large part of seeing for me. So, if the picture is absent from this mix does that mean I am not seeing? Can one missing variable cancel the entire experience?
I don't think so. But I also dont think it would be correct in calling it seeing. Pictures have always been what is referred to as seeing, and removing those from the equation would make the experience equal somthing else, likely as influential, just different.
Interesting array of thoughts, both general and specific. Certainly one of the issues raised by blindsight (among other phenomena) is the possibility that it might sometimes pay to let "our I-function really let go and totally rely on [the rest of] the nervous system". Which fits with some of the discussion above about athletic performance and intuition? On the other end of the spectrum, it is interesting to try and imagine "experience" without the picture in the head. Given all the other things you say experience consists of, maybe an absence of the picture in the head wouldn't be so significant? PG
However, then I thought about our discussions in class about other species and their vision. They see differently than us, yet they do have memories, but to a lesser degree. This led me to become a little confused about vision and memory.
I also wondered if there were some connection between the degree of visual acuity and memory mass. In other words, is it true that those who can retain more information have poorer eyesight and need to wear glasses/contacts lens? My curiosity stems from the old myth that smarter people need to wear glasses. :)
Oh, I also thought that our other senses (smelling, tasting, hearing, touching) may come into play in regard to correlating with memory. I was curious to know how they fit into the big picture. I do not think that these senses would be as complicated as our sense of sight, but you never know.
Lots of people interested, like you, in the memory issue. We'll get to it (imagination we did a little bit, and will get back to). Now, why exactly should people with poor eyesight retain more information? Because they need it more to construct pictures? Interesting. Not impossible. Would be worth looking into. PG
We've talked about how our eyes mess with the inputs they receive before passing the information on to the I-function. At the same time the info "I" get is closer to reality than straight data inputs from the eye would be. At least I can manage to not walk into walls and I can relate to other people. This makes me think of bats who use sound, and certain aquatic organisms that use electromagnetic fields to orient themselves within reality. Blind people can use other senses to understand reality. One big point from our discussions of vision seemed to be that the nervous system is processing the inputs it receives about reality without the help of the I-function. Therefore, how can we be sure that the reality presented to us is true? After all, the I-function does make important decisions and exercises considerable control over the body. If it is responding to incorrect data then the body may suffer. I think that what we have learned with regard to vision shows that I am not totally in control; "I" am at the mercy of my body. This is hard to accept because I think of my body as something that works for me (it works for my I-function). The importance of the body is linked to its necessity as a support the I-function. Most scientific, philosophical, literary, and historical endeavors are driven by and for the I-function. It is hard to accept that the I-function is so dependent on the body which is ultimately unreliable. The body may start out, or become, handicapped physically or mentally. This means that the I-function is handicapped physically or mentally. Ultimately the body dies out taking the I-function with it. Mankind has tried to work against this by building great monuments and writing for posterity.(I feel like I've said this before so I'm sorry if this is just repetition)Our study of both the input side of the nervous system and the output side of the nervous system show that we don't necessarily need the I-function for either. So what is it there for? I don't have any concrete thoughts about that yet.Another big question for me is, what if it wasn't there? One human ambition seems to be to extend the life of the I-function beyond the death of the body through works of posterity. There is some sense in which aristotle, plato,shakespeare, and marie curie among others live on. Organisms can survive without an I-function, but it seems almost pointless without one. I have more thinking to do on this subject.I seem to be just stating the obvious. (note: I've used the word body to refer to everything about a human, including the rest of the nervous system, which isn't the I-function)
"I" don't think you're stating (or repeating) the obvious at all. To the contrary, it seems to me you're raising and wrestling with a very interesting and important set of issues. Indeed, "most scientific, philosophical, literary, and historical endeavours" are, it seems to me, "driven by and for the I-function". So the notion that the I-function is a restricted and not entirely in control part of the nervous system (and rest of the body), if its true, has not only implications for individuals but broader ones as well. The notion of human ambition including efforts to "extend the life of the I-function" is I think not only a good characterization but may also be a useful way into the question of what the I-function does, is good for. If I don't say something along these lines in the next weeks, remind me? PG
Very good point, and one we will get to quite shortly. Yes, indeed, the brain can (and does) not only fill in images but create them entirely. Interesting question to think about (and we'll discuss): what is the state of the I-function during dreaming? PG
So how important is the picture in the head to the ability to have a memory, or can one not have a memory without the picture in the head? Obviously a blind person is capable of retaining sounds and tactile information, their memory does not just vanish with the loss of sight. But did memory evolve as a result or concurrently with the evolution of the picture in the head, or is it an independent function. I always see young animals, mainly mammals, on nature shows that are learning about their environment and exploring what they can and cannot eat and how to fight. Those things that they learn in their early years they must remember for the rest of their lives in order to survive. So is the assumption then that without a neocortex an animal has neither a picture in their head nor a memory, thus leaving the animal to interact with the world as it sees it and never learn from any of it's experiences? Can frogs not learn?
I was also curious about how much this has been looked at in humans. Obviously you cant go running lab experiments on humans and damaging their neocortex, but of those that do have damage, how complex is their blindsight? Can they do more then point at a light? Could they walk down a street without assistance and avoid obstacles in their path? Although you pointed out that we can use blindsight in our everyday lives when we dont even realize it, like while driving, how much could we revert back and depend on a way of seeing that we haven't ever solely depended on as humans.
Blindsight is a relatively recently described phenomenon and so still both somewhat controversial and understudied. There's a recent review in Brain if you want to see more or less where the field currently is (P. Stoerig and A. Cowey, Blindsight in man and monkey, Brain 120: 535-559, 1997). Yes, people with visual cortex damage can do more than point, how much more is still a little unclear (but clearly depends on how one elicits performance). I'm not sure anyone has looked at the matter naturalistically (walking down a street), but there may be anecdotal information on the web. What is certain is that people with blindsight don't report a "hole", just like one doesn't see the optic nerve head. We'll talk more about the relation between seeing and memory, but all sorts of animals (including frogs) are certainly capable of learning (which is probably a different thing). PG
And, perhaps, what makes each person valuable to every other, since no one's picture is perfect? And maybe its not non-sensical, but rather a highly effective (the most effective?) way of making sense of an inevitably uncertain world? Maybe its the world that's scary, rather than what the brain does with it? PG
VERY interesting question, to which I don't know the answer, and suspect no one else does either. There is a tendency to presume that stereopsis depends on visual cortex (the area damaged to produce blindsight), but other areas of the brain also get input from both eyes. And there are, of course, other cues for distance judgement, as we talked about. Much make an interesting research program out of that idea. PG
I wondered if it could be that the picture is all over, not contained or confined to a specific region of the brain as we would expect. The same observation can be made of the I-function. Could it be that it is all encompassing of our brain, at the same a property of our brain as it is the entity encompassing not only our brain but our being alltogether. Could it be a spirit, not physically defined? Is the idea of the spirit an expectation of the science of biology? Could the I-function be as physical in that it can be studied and anylzed by us when we examine the brain and the human body as it is spiritual and undectable by our science? Are we putting too much constraints on 'what is' by our demand for physicality? It doen't necessarily reduce to a question of magic but rather to a question cannot by its nature be seen and detected in our laboratories? Do we stop researching then, by all means no. Maybe simply we aught as scientists not to get too caught up and emprisoned by our laboratories and look beyond for these answers.
Very interesting, very sophisticated set of thoughts. Yes, we can't find the picture using certain techniques, nor (perhaps, actually you've anticipated the conclusion) the I-function using particular techniques. But that doesn't mean that it isn't there ... we need "not to get too caught up and emprisoned by our laboratories". Perhaps our laboratories have been designed to look for things at particular places and, as you suggest, some things are different, being instead in lots of places at the same time. No, that's not magic (it doesn't even necessarily mean not "physical"), but it does mean we have to look (and maybe even ask the question) differently. PG
Furthermore, I've always seen vision as rather concrete. You either see or you don't or the picture is just blurry. I recognized means of sight is variable, after all I was very happy in second grade to learn that I don't have bug eyes and never will. Still, talk about the cerebral cortex never seizes to challenge me. I'm still not sure what to think about the significance of the picture in my head, but I'm glad it's there.
I'll end with a personal anecdote from the other day. Last week in another one of my classes we took the army alpha, an "intelligence" test administered to draftees during WW1. My professor made us take it to demonstrate that it was in fact really more of a literacy test with extreme cultural bias, but I found it personally interesting for other reasons. One of the subsets involved a series of sentences in which the order of the words was scrambled. The object of the test was to determine whether the sentence was true or false in as short a time as possible. For example, the sentence "grass blue is the" would be false. I completed the test in literally about half the time of the rest of the students in my class with 100% accuracy. I am dyslexic. Thus I have been wondering if, how, and on what level this test was effected by something which usually sets one at a disadvantage in timed measures of literacy. Could it be the way I'm seeing the words or is it something deeper in my perception? What do you think?
I think I'm fascinated, and would like to know more, from lots of points of view. Not the least of them is the contrast (?) between what I assume are your own experiences and your simultaneous presumption that things look the same to all people. Can you describe what writing looks like to you? I wonder if it looks different to someone who's not dyslexic (and whether such a difference could come out from "describing what it looks like"?). I'm equally intrigued by the test anecdote. One of the problems (so far as I'm concerned) with categories like "dyslexic" is that they are created in recognition of a "deficit". My guess, though, is that virtually all variants of nervous system organization (of which "dyslexia" is presumably a set) have more wide spread effects, so that there are probably enhancements associated with them as well. It would be very interesting to look into that by trying to define more precisely what the "enhancement" might be that your experience suggests exists. PG
You've said plenty to take us to the next discussion. Yep, pictures without optic nerve activity, which influence behavior, and in which you are involved. Let's see what we can do with all that. PG
The bilateral tectal outflow model proposes two sets of descending pathways capable of generating visually elicited prey orienting turns: crossed pathways responsible for turns contralateral to the lesioned hemisphere of the brain, and uncrossed pathways responsible for turns ipsilateral to the lesioned hemisphere. The relevant articles (Kostyk and Grobstein, 1986) defend rigorously the existence of bilateral uncrossed descending pathways. The existence of crossed tectal outflow pathways, however, was documented half a century earlier, and required no defense.
Although I have known since elementary school that animals, including humans, process visual input in the hemisphere of the brain contralateral to the eye that receives it, I still do not understand why. Light coming from the one side of an eye is refracted so as to stimulate the retina on the opposite side of the eye. So what? This observation seems insufficient to explain pathway crossing in the visual system. Furthermore, crossed pathways are not limited to the visual system. It is common knowledge that the right side of the brain controls limb movement on the left side of the body. It seems unlikely that this organization is somehow related to the refraction of light by the eye's lens. Perhaps the crossing of pathways is a means of interconnecting otherwise remote anatomical regions. This might result in a sort of neuronal "hybridization." Disparate neurons often display differing intrinsic functional characteristics. Perhaps their interconnection engenders emergent properties which would not result from the interaction of more proximate neurons that display similar functional characteristics.
Alternatively, crossing pathways may enable the brain to capitalize on the sensory information it receives via "cross-referencing." Already in our study of neurobiology we have seen several illustrations of the brain gathering information on a single phenomenon by various methods, and then comparing the data to construct a coherent interpretation. In the visual system, examples of this information-synthesizing process include distance perception via binocular parallax, and color perception via the comparison of the distinct yet overlapping spectral sensitivities of specific photopigments. Whatever the cause, the crossing of pathways must result in some beneficial property of the nervous system which would be impossible via uncrossed pathways alone.
As I said when we talked today, crossing is a problem that's been on my mind for fifteen years or so. "Neuronal hybridization" is interesting, but I'm not sure enough what you mean by "engenders emergent properties which would not result from the interaction of more proximate neurons ..." to give up another fifteen years of thinking about the problem. Glad you're interested though. PG
You told me that the important part was the input and the output (I think that was part of what you were telling me), but it is essential to put the same input into the same thing and measure the output, not outputs of different things. The animal may always want to accomplish the goal (get the worm) every time, but may differ the means to learn. With your driving example, you drive a different way because the day before you went a certain way already. I wonder if there is a pattern in the progressive hops/rotation of the frogs, if they hop in a systematic fashion to discover the best way of doing something. OK, I think that we are talking about the same thing. But, does the Harvard Law essential say that an animal will change over time so that their actions can not be predicted because we do not know all of the data of their lives? Although, I thought that you said that even if we had all of the data, we could not predict their next move. But, if we had information on all of the connections in the NS, the properties of everything (molecules, cells, etc.), and knew all of the alterations made over the life, couldn't we predict the actions? We can predict the behavior (get food) with reasonable accuracy. If we had more data, couldn't we predict the move?
Does this relate to humans? You must combine the experiences in life (alterations made to the NS), with the genetic information? What is the I-function in relation to this? Can it override the normally predestined response? I remember playing Find Serendip. I started at the first level and once I understood what was going on, I could guess correctly with only a few guesses. As I moved up the levels, some I got on the first try, while others took 3 or 4 times. However, no level took more then 6 or 7 guesses. The game was supposed to be random though. I think that if we knew everything about the computer, we would be able to predict the next hidden serendip location. When I play tetris, after awhile I can predict what the next move will be, though it is random. Are animals the same? Does our I-function allow us to know what we should do(based on our knowledge of our lives and everything) and not obey it and do what ever we darn well please? I was thinking of how we could test this. I was just reminded of twin studies and how two twins that had grown up together (and sometimes apart) could be taken into different rooms and asked to say something random. The thing that I read said that a lot of times, that random thing would be the same thing that the other twin said in another room. I wonder, if the twins were told what was being studied and that they should pick something random that their twin would not say (to rely on what they know of themselves and the other twin and what the twin would be likely to say) if they could pick something different from the other twin or if it would still be the same. I think that they could use their I-function to pick something different. I wonder if other animals could.
Sorry, I did not think through this essay as I usually do before I wrote it. These are just thoughts I had about it.
No apologies needed at all. Very interesting thoughts, wrestling with very real and significant issues. My guess is that we and frogs are NOT predictable, even if we knew all inputs, and that's important but that's very hard to prove (see my replies to Rachel and Jonathan above). Twins are indeed are interesting case for thinking about all this, and we'll talk more about that. And about your intuition that the I-function plays a role in increasing unpredictability. PG
Very. And yes, I'm quite sure there is "deaf-hearing" in real life. Whether a comparable clinical syndrome (following a brain lesion) has been described I don't know and is an interesting question. There are though a variety of other comparable syndromes outside the visual realm, including anosognosia, a denial of a deficit involving parts of the body. You might enjoy an interesting finding suggesting there may be, in addition, denial of deficits in corresponding parts of the bodies of other people. We'll take more about some interesting possible implications of this in class. PGSerendip © by Serendip 1994- - Last Modified: Wednesday, 02-May-2018 11:57:49 CDT