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The I-Function, Automatic and Cognitive Processing
Given that the brain is behavior, it seems perfectly logical that the sensation of "you" is created by a subset of the nervous system (the "I-function"), and that the subset will not necessarily be involved in all actions undertaken by the nervous system. This, of course, results in the strange phenomenon that you (or your nervous system, anyway), can do some things only if "you" (the part which has the sensation that you're consciously controlling things) do not get involved. Two particularly interesting concepts stem from this: first, the nervous system is better at doing some things than "you" are. This is a somewhat disturbing thought, but the utility of this, as well as the fact that there are some things that are better done with "you" involved, will be discussed in subsequent paragraphs. Second, much of what you do "you" are not doing. A great deal of the processing and actions you carry out each day are done without input from the I-function. Given the degree of effect that this phenomenon should have on behavior, one might ask what is the purpose of this separation between the nervous system at large's activities and those involving the I-function, and how does having an I-function make an organism evolutionarily more successful than one which does not have it? (Assuming that having an I-function is more adaptive). To address these issues, it seems useful to explore the concept of automatic processing. PPsychologists define automatic processing as a process which, in the presence of a triggering stimulus, runs to completion without the need of conscious monitoring. This "conscious monitoring" constitutes the second form of processing: cognitive. Cognitive processing is intentional, requires attention, and is limited by the amount of processing capacity available. These two types of processing work together in the evaluation of everyday information.
One can see how automatic processing could be equated to processing carried out by the nervous system in the absence of "you," and cognitive processing the processing carried out in conjunction with "you." When you touch a hot stove, your nervous system automatically processes the input it is receiving and arranges for the removal of your hand. The key is that this all occurs quickly, and without "you" getting involved. If "you" were to take part in the process, it makes sense that it would take longer. The input would have to travel to and get processed by yet another portion of the nervous system before any reaction to the stimulus occurred. This addresses the utility of the dichotomy between the nervous system and "you": for things which need to be done quickly, the less players involved, the better. It also therefore makes sense that in the initial evaluation of a situation or stimulus, automatic processing (read: processing without "you") would be beneficial in order to scan for potential dangers. Yet another benefit of processing without "you" is efficiency. When some aspects of a stimulus can be assessed automatically, the processing capacity which would have been necessary to evaluate them cognitively are spared. By processing some of the more mundane information without "you," it leaves more capacity for "you" to deal with more complicated information. This would explain the fact that a great deal of what you do each day is done without the sense of "you" doing it--if "you" were to attend to everything that you do, you would probably not be able to do anything at all.
There are also, however, disadvantages to processing without "you." While automatic processing is faster and more efficient, it can result in very important aspects of stimuli being overlooked. By classifying a stimulus in terms of mundane things that do not warrant the attention of "you," one might overlook the stimulus' uniqueness. In particular, stereotyping is the result of automatic processing. Some researchers have shown, however, that if a subject is forced to process a given stimulus cognitively (with "you") rather than automatically, stereotyping can be alleviated. I therefore propose that the benefit of cognitive processing such as that carried out by the I-function is to make finer distinctions between somewhat overtly similar stimuli. While this ability is not always exercised, it exists in some organisms. In particular, it would be useful for organisms which have more complex social interactions, as discriminations at a finer level would be necessary. (i.e., Instead of just predator/non-predator distinctions, organisms with more complex social worlds may need to keep track of who are kin, friends, and enemies within their own species, not to mention the distinctions among members of other species.)
It seems possible that the I-function is in fact the sole domain of animals with complex social interactions, as if you put a piece of fruit on a monkey's head and show it a mirror, the monkey can use the image to figure out where the fruit is, and grasp it. This would seem to indicate that monkeys and have a sense of self. Humans, of course, can do this as well; however, monkeys and humans are the only animals which have this ability. Since monkeys and humans are the only animals which overtly manifest an I-function, and they also have the most complex social interactions of all the animals, it appears that the cognitive processing of the I-function may have evolved for social purposes.
Very interesting, sophisticated thoughts, wrestling (appropriately) with relation between neurobiological and psychological constructs. "Cognitive" is, it seems to me, a slippery term. Do you mean "intentional", in the sense of "having a purpose"? or in the more technical sense of "being aware of having a purpose"? The former certainly doesn't require an I-function. Nor does "attention", except in a sense which again presumes intentionality (in the technical sense). In short, I suspect the psychological "cognitive/automatic" distinction is reaching for the same set of issues as the "I function/non-I-function" but I'm not sure its a clear distinction in psychology (or even as clear a distinction as one can make neurobiologically). This aside, your thoughts about what the two systems are good for seem appropriate, at least as a subset of an answer. We'll see if we can come up with more of an answer as we go along. PG
I'd like to see if I can get a little farther with the athlete/CPG idea. When I was referring to the lag time when you tell your body to stop performing a practiced action its not a whole lot but enough to be noticable. If I was picking up a baseball for the first time and someone said stop in the middle of the throw I would, but since I have done this innumerable times I know that my arm will probable slow down but the ball will still probably slip out. The reason I believe is the CPG vs nonCPG. In the original instance it is taking a specific input to cause my arm to throw the ball. Therefore at every junction it is possible to stop. On the other hand if Ive practiced a lot I have created the CPG that once started continues without extra input or much reafferent information, ex. doing things with your eyes closed. This line of thinking has led me to some more thoughts. I know from my own experience that even if I have never done a sport before I still tend to be better at it than other beginers and if it is at all similar to a sport I have played that I am usually quite good. This leads me to believe once a CPG is initiated it is easy to branch off. What determines which branch you will take? That still perplexes me. The question of what is actually happening when you practice something is interesting. I'll make an attempt to trace that from the neurobiologists point of view. An easy action, like serving, seems to involve afferent and reafferent information. If you throw the ball up then hit it you rember where all your body parts were and how it felt. If its a good hit you try to repeat it, if its bad then you determine what made it bad and you affiliate that body action with a bad serve. I do this when I shoot the basketball or set, I know immediately if I did it wrong by how my body felt. When you practice you are telling your body what are the right and wrong movements to make. This leads me to questions of learning. Im having a hard time figuring out what causes you to become better. I guess simply by knowing what your body should and should not do you are able to correct it a little bit at a time until finally you rarely make a mistake. I have a feeling thats material for another essay. Michelle K. Bostick
Interesting thoughts. Well worth another essay, or two (or more ... the development of athletic skill has always seemed to me particularly rich turf for insights into how the brain works ... there's actually some literature on this if you'd like to do some reading). The CPG idea is a good starting point, but things are certainly more complex (and probably part of the reason why you still lose the ball is physical inertia). Most highly skilled athletic performances are not simply the ability to generate stereotyped motor output (as an acquired CPG might do) but instead involve a sophisticated interaction between internally stored information which not only generates output but also handles needed incoming information particularly effectively. Which is to say, what one learns is not only to create an output but also to adjust it rapidly and appropriately based on incoming information. So what's being learned? And what is learning? And how come it transfers (as you say) to new situations? No good answers to any of those questions, but do suspect that practice is as much or more a process of trying out different variants of things to see what happens as it is of creating a stereotyped CPG. PG
"Where and What is the 'self'?"
Ronald Melzack in his article "Phantom Limbs" explains his theory that the brain has something called a "neurosignature." This neurosignature is a network of neurons that continuously generate a sense of body, a type of sense of self. Damage to the parietal lobe causes phenomena such as disbelief that one's own leg is not part of one's own body (some patients push their own leg out of the bed believing it belongs to someone else).
The generation of a non-physical "self," felt as control over the body's functions, can also be located in the brain. When the basil ganglia is damaged, the person either has trouble making voluntary movements (deciding to move an arm, for example) or can not control spontaneous movements generated by the body. So the basil ganglia seems to be a connector between "self" generated control of the body and the patterns of activity that are generated spontaneously by the nervous system. When the sensorymotorcortex is damaged, contralateral spastic paralysis is seen. Normally, this part of the brain appears to inhibit patterns of activity generated elsewhere in the nervous system, like behavior designed to counteract gravity (when the eighth nerve, which registers gravity, is cut, spastic paralysis relaxes). But this inhibition can obviously be turned off when the behavior is desired by the nervous system, or by the "self".
I can not say that the "self" is in any of these parts. I really like the idea of Ronald Melzak that the sense of self is generated by a network of neurons. That leaves open the possibility of a widespread (all over the brain) network, which, with the above examples which are all over the brain, makes more sense than a concentrated spot in the brain dedicated to generating a "self". It is important also to remember that behaviors generated by the "self" is only a subset of the behavior generated by the nervous system. This is even stronger evidence for me that the "self" is not an isolated part of the nervous system. The "self" can only be as functional as the nervous system is functional, and must draw its abilities from what the nervous system has to offer. The nervous system determines the neurosignature of the self.
The behavior that seems to link up with this idea of a neurosignature is handwriting. This is one activity that relies on complete harmony between voluntary and involuntary behavior. You form the words to write in your head while your hand involuntarily carries out the movements to correspond to the word commands. You can not write without commanding the words, using the "self", or without relying on the movement of the hand, the result of impulses from the non-self part of the nervous system. It is not surprising then that graphology, the study of writing, has been used as a way to determine someone's "self." I have even heard that the theories behind graphology are used as a type of therapy; teaching someone to write a certain way must influence the non-self part of the nervous system.
Interesting thoughts, particularly the handwriting connection, though I'm not sure I agree with all your points. Why is behavior generated by self as a subset of behavior generated by the nervous system evidence against the notion of self as an isolated part of the nervous system? I agree that "I" can only act through the (rest of) the nervous system, but since some actions involve I and others don't, "I" can't be synonomous with (distributed through) the entire nervous system. That, it seems to me, argues that "I" is a particular place in the nervous system (or at least a distinctive pattern of activity which can be present or not). What may be at issue here is the relation between "I" as the agent in voluntary action and "I" as the complete self (personality?). For the latter, I think I see your argument, and so we may need to distinguish several different meanings of "I". As for handwriting, I see your point that "I" can think words, and some non-self-aware part of the nervous system translates that into movements. What's intriguing, though, is that "automatic writing", of the kind purported to occur in seances, might be interpreted as a "non-self" part of the nervous system providing the material which another non-self part translates into movements. Possible? PG
The continued discussion of the central pattern generators makes me wonder if there is any case in which one would be at a disadvantage by having a central pattern generator in opperation. For problems in which the circumstances change every time, such as running a maze, is it to our disadvantage to rely upon our past experiences or memories stored in the central pattern generating areas of our nervous system? In problems with multiple solutions, do our brains tend to revert back to the known pattern as a rule, or to create more patterns in the process, even though this would take longer? I remember reading an article in Newsweek a few months ago, in which the amount of activity in the brains of individuals first learning to play Tetris were observed. It appears that as the subjects got better at the game, the active areas of their brain decreased. If so, this would mean that the brain opts for efficiency rather than extent of use when learning new things. If this is the case, do we not risk missing some vitally important aspects of a new problem as it becomes more difficult or automatically assuming that we have encountered the same situation before and therefore jumping to the conclusion that it may be solved in exactly the same way merely because the central pattern generator dictates a certain course of action.
Concerns over the spastic hemiplege include the extent of effects upon primates. Knowing that the flexion/extension of a particular limb depends upon the organisms orientation to gravity, one begins to wonder about the variety of different effects it would have had in the course of evolution. Did the fact that the orientations of different regions of the brain to gravity dictate in part which species eventually walked and which did not? Would species that lacked tails and could therefore not hang hang upside-down as easily be more inclined to walk because of the way the areas of its brain oriented itself to gravity? AAnother aspect of interest in regards to the spastic hemiplege is their ability to protect themselves if an object is thrown at them. This same sort of behavior has also been observed in autistic and catatonic individuals. This heightened awareness regarding the personal space of the body lead one to wonder if the two are linked by virtue of location and if so, are there further links in regard to the amount of control specific area of the brain have over disorders which we know little about.
The nervous system's ability to reduce specific behaviors into component parts provides a variety of interesting evolutionary advantages. First and foremost, obtaining control slowly enables individuals to develop the fine motor control absent in non-mammals, giving organisms with developed neocortices the edge when it came to coordinated movement. Secondly, the lack of control over individual digits, for example, aids in the variety of vital grasping reflexes found in infants and very young children. (Although this may appear trivial now, one relizes the full significance upon consideration of the lifestyles of our hunter-gatherer ancestors in which survival depended upon being able to hold on to something/someone over long distances.) Finally, this sort of arrangement forces individuals to interact with their surroundings in a way which encourages maximum exposure to a wide variety of sensations. This optimal effect would not necessarily be employed as widely if the ability to control one digit were present from birth.
Hmmm. LOTS of interesting thoughts, on a variety of topics. I hadn't thought about development of fine motor control from the perspective you're suggesting: that its an evolutionary add on with a past for which gross movements were more adaptive, but that's certainly a possibility. Interested in evolution, huh? Careful about adaptiveness of things, for reasons we mentioned in class. And I suspect that with regard to spastic hemiplegia, brain organization adapted to body organization, rather than the other way around, but there are indeed a host of different vestibular organizations in different animals (flatfish being particularly interesting). Can direct you to some reading in this area if you'd like. Am interested in your connections between movements in hemiplegics and those in catatonia/autism. How do you happen to know about those, and how can I find out about them? Finally, I agree that the issue of whether discovery of solutions to problems (CPG creation in your example) lessens the likelihood of further potentially useful exploration is a very real one. Any thoughts on how to explore it? PG
This past week in class we discussed voluntary and involuntary movements. An example of an involuntary movement is moving your eyes side to side in a slow, smooth way. This occurs when you are watching a bird fly by--or any other thing moving side to side--but you cannot command yourself to do it without a cue to watch. If you try, your eye movements will be jerky.
We then questioned if walking is voluntary or involuntary, and decided that it could be voluntary--because you could command yourself to do it--but was also involuntary since you do not constantly command yourself to continue walking when you are doing so. There was some discussion in the class over this thought, and I think some of the students did not like the terms being used. "Involuntary" means for many an action over which you have no control, and here it was merely being used to signify an action that is not actively being ordered consciously. If the first definition were used, it could only be used for such behaviors as heat beat, pupil constriction, etc. I think that to clarify the definitions, a different terminology should be used, such as "commanded" and "non-commanded" actions.
The whole idea of "you" ordering a command led to a question: Where is "you"??? We must assume that it is located in the nervous system, since we are not allowed to speak of souls in this course. We must also assume it is a subset of the nervous system, since this fantastic system is capable of performing activities (such as the smooth eye movement) that we cannot command.
People with contralateral spastic paralysis--who are paralyzed on one side of their body--say they cannot move, yet they do move their arm to block an object flying at their face. They do this without commanding; indeed their "you" cannot will the arm to move. In a small percentage of people with strokes on the right hand side of the brain, however, nearly the opposite holds. These people cannot block an object coming at them--they are truly paralyzed on their left side, but they claim that they can move their arm and in fact do! (See 28 January 1996 _New York Times_ science section). With all these different kinds of problems going on, I'm sure *I* cannot say where the "you" is located.
Nice set of thoughts, critiques, additions. Thanks. I agree that people are used to "voluntary/involuntary" as categories to describe different kinds of movement, and so perhaps it would be less confusing if some other terms were used. On the other hand, I suspect that the "voluntary/involuntary" distinction is in fact the same distinction one sees in other contexts, and hence that the comfortabless with that distinction in some contexts itself reflects a misunderstanding of what's at issue. In any case, you have the point I was trying to make, that "I" must be a subset of nervous system activity. We'll see if we can make (more of) a case for where its located as we go along. I missed the NY Times article, do you have a copy? PG
Because of the break, I am not sure what topic to write on , so I will just reflect on some topics that interest me. I would first like to return to CPG. One of the essays I have read on the News watcher made me think about the way CPGs are created and I made following connection between learning and CPG. During the break I got to drive extensively and I could see how ÒautomaticÓ my movement and reactions became. At the beginning, my father told me: Òan experienced driver does not think about driving - if there is a situation that requires a quick reaction, you have to be able to step on the break without any reflectionÓ. I could see how in some time I was getting more and more relaxed behind the wheel, music or conversation stopped bothering me and my reactions moved to the level of intuition or impulse (or I donÕt know how to call it). Then I thought, maybe not only learning of movements is of this kind. Maybe learning languages is a CPG creation too. First of all, our native languages are something we never forget, never think about, somehting that comes out naturally and without any need for sensory input. But this can be extended further to learned behavior, e.g. second languages. I have observed on myself that English has become completely natural speaking and thinking language for me. I never translate from my native language into English - the words come out automatically. Sometimes, if one asks me how does certain word translate into English, I donÕt know, but when I speak English without thinking about it, I use the word I was not able to recollect when asked. Further, there is certain way of learning which alter oneÕs thinking completely. One starts thinking more logically, can comprehend very abstract propositions etc. This way of thinking is something that becomes a part of us after we acquire it. I believe it impossible for me to forget what I am learning in my math classes. It feels like I have new roads created in my brain. I am not sure if learning of this type can be explained through creation of new Central Pattern Generators. Now, there is something I do not quite understand. CPG is a mechanism within our nervous systerm which is responsible for supply of information for pattern of activity of neurons. If CPG can be acquired, is our experience recorded in our personality by such aquisition and development of CPGs? And how is memory related? For example facts we memorize at school but which we forget on the first occasion - it seems that these short-term visitors to our memory also ater our brain/behavior? I leave that question open to myself.
I also remembered our class during the break when I watched Appollo 13 and one of the astronauts started vomiting after reaching an orbit of Earth. At the same time it was not his first time in the space. How come he still felt motionsic? One would expect that if he got used to moving around in space the first time, then he should not have problems his second time. From this fact I would expect the Ògetting used to motionÓ be the same as gradually decreasing the sensitivity to motion. I also thought that perhaps it should help if a person who suffers from the motion sickness would mathch the corollary discharge to the sensory input by moving around in the car. Can the match be artificial? (Just a thought)
My oh my. A really interesting set of thoughts. I'm glad you didn't feel constrained by having something you were supposed to write about. The driving metaphor is a very interesting one. Yes, I think one acquires CPG's in the strict sense while learning to drive, and your observation that your driving is progressively less disturbed by irrelevant sensory inputs is a good one in this connection. At the same time, as you say, one may want to generalize the CPG concept into something which is less strictly related to movement and its independence of sensory input. Sensory inputs actually ARE of course important when one is driving; what the acquistion of skill involves is not becoming independent of sensory inputs (CPG's in the strict sense) but rather becoming less "aware" of them (and of one's own generation of motor outputs). Early on, the "I function" is very much a part of learning to drive, while later one drives more skillfully and comfortably without it. What this presumably involves is not only the creation of motor sequences but also of sets of expectations and responses biases for sensory input which can influence behavior without the need for the "I-function". This is a different idea from the strict and historically derived idea of a CPG, but there is some reason to believe that even strict CPG's might be better thought of as sensorimotor templates (including input expectations). I've been trying to think of a way to make this clearer in the course, and your thoughts will help. Thanks. It would be worth looking more closely at the current CPG literature (and some older things, including the curious cricket cross breeding results) to see how much broadening of the CPG concept is already emerging there. Any interest in doing that? Your open questions and thoughts about astronauts equally interesting. Sure, betcha CPG acquistion alters "personality" (will talk a bit more in course about what that means in relation to "I-function") and can be without ability to "recall" events using "I-function" (will talk more about this too). And experiences can indeed alter things with different time courses, different degrees of stability. Which, of course, means that "memory" is not one thing, but a variety of different things. PG
The idea that there are some actions that "you" can consciously controll, while there are others that are involentary is a very interesting idea, but a very difficult one to come to grips with.
How do we come about making a decision that "you" has supposedly made? Is it really any different from our nervous system making the decision for us? The point is that it appears as if we can think in our heads a command to the body and nervous system, but how did we come about to making the decision to act in that specific way? Was it really our choice, or does it just seem that way because it passed through our conscious thought before doing something?
In sports people talk a lot about muscle memory, about taking thousands of cuts in a batting cage or shooting hundreds of free throws in the gym, all for the purpose of "training" the muscles to act a certain way. From a neurobiologist standpoint this would be writing new motor symphonies. But take swinging at a pitch, for example. Obviously no two swings are the same. Sometimes a hitter has to slow his/her swing down, speed it up, or move it. Or how about when a batter checks his swing, or uppercuts his swing to loft a fly ball? Obviously there are not different motor symphonies for each of the different actions, but rather the person is making a conscious decision, based on the surroundings (situation, speed, trajectory, ect.) But then the question arrises of how does the person make the choice, and is it really conscious? We talked about it after class, and the result was I was as confused as ever, and hopefully we can talk about it today in class.
Probably a number of times, to try and get it straight in all our minds. Yes, I think the obvious questions are WHO makes a choice, and what that means in various circumstances (and that we WILL get to a little further on in the course). My guess is that checking a swing, and other adjustments by a skilled athlete do NOT in fact involve a conscious (voluntary?) action, but rather much more rapid involuntary ones. Which is to say choices are indeed being made, but without awareness of having made such choices (until after the fact). From that perspective, the issue becomes if all of that kind of sophisticated "choosing" can be done without "I", what does one need "I" for anyhow? PG
My feeling is that there is a fairly simple distinction between voluntary and involuntary movements. But in order to make that simple distinction it has to be determined where in the nervous system the sense of self or "I" is located, a task that is not that easy. There are arguments as to which aspect of the nervous system is more important, the "I" or the rest of the nervous system. There are two possibilities as I see it; either the I is located only in the brain or it is distributed throughout the nervous system. I am more of the inclination that the "I" is in the brain rather than in the whole nervous system. We don't consider paralysis a loss of oneself which would be the case if the self were in the entire system. Paralyzed individuals are still themselves with their own personality. For individuals with paralysis the argument may be different.
I feel that the "I" is located in the brain and is the part of the whole system that controls the voluntary movement or behavior of the body. The "I" to me acts like the central pattern generator for the voluntary movements. When involuntary movements occur the I is not the one to control them, but rather, involuntary movements seem to result from pattern generators in other parts of the nervous system. There is proof that the I is in the brain through the phenomenon of spastic paralysis where the person seems to lose part of their I and through that, part of their control over voluntary movements. Damage to certain areas of the brain result in this loss of voluntary movements but the mechanisms for involuntary movements are still in place and not damaged. This to me shows a little more distincly our self is located.
Some interesting, appropriate thoughts. But, localizing "I" in "brain" is pretty general. Probably need to do better, no? And I'm not sure I'd want to equate I with "central pattern generator" (something which doesn't require input?) or at least not sure why you make that argument. The other thoughts yours trigger have to do with difficulties in saying, in any given, case whether the "I" has been affected by a disturbance or not. Its certainly still there in the cases you mention, but is it different? Let's see how much of this gets clarified as the course goes on. PG
It seemed at the beginning of the course, that the more we know about the Nervous System, the easier it is going to be to locate the "you" and to define clearly what it is. Yet even as the complexity of the structure of the NS becomes more clear, and as the distinction between the actions of the NS and "you" is more distinct, "you", or "I" is still not an entirely defined concept. We have discussed several areas in the brain (cerebellum, central motor cortex) which receive the information about the actions of the organism, (also the result of the actions), and coordinate them. Cerebellum, for instance was defined in class as a site of an ongoing comparison between corollary discharge signals reporting what the NS is trying to do, and reafferent signals indicating its effectiveness. If we think about "I" as something for one part responsible for the coordination between the actions of the NS and a higher level of organization, damages to which seriously impair the ability of the organism to function, then we can conclude that part of it is located in the cerebellum. Though we have not yet clearly defined the "I", we assumed that it is something connected with conscience of being, and as such it will probably not be found in just one specific place, although the rostral end of the NS is its approximate location.
The separation between the abilities of the NS and of the mind -- "I" discussed in class, further defines the attributes and abilities of both. Even if central motor cortex looses control of the organism's functions due to some damage (if "you" loses control), the NS doesn't necessarily. This I think, brings in another separation between the "you"-- the brain, and the rest of the NS, giving perceivable boundaries to both. Another interesting distinction made in class was between the voluntary and involuntary movements: voluntary are the ones "you" can do, and involuntary are those only your NS can do. If NS can't do certain things, and new patterns have to be created for doing them, than the concept of "you" acquires yet another trait -- it is something with a capacity for creating new patterns and for adapting to various situations.
Interesting (and helpful) set of thoughts, anticipating at least some of where we're going. Careful though, you SOUND a bit as if you are distinguishing between the nervous system and "you", whereas I presume you mean (as I do) a distinction between what the nervous system as a whole can do and what a subset of it (involving "you") can do. From that perspective, I'd draw a slightly different conclusion than you do from your considerations of cerebellum. It is clearly, as you describe, a "higher order" coordinating center, but there is little of no loss of "self-awareness" when it is damaged, from which I'd conclude that it is not a key element in whatever subset of the nervous system constitutes "you" in THAT sense, and that "higher order coordinating center" is not the primary characteristic of "you". Which of course leaves open the questions of where "you" are, and what such a function is good for. On the other hand, your intutions that it is distributed and yields a capacity for new patterns and adaptations point in directions we'll be going. PG
As we continue to learn about the nervous system and its structures, it seems as though more and more types of behaviors can be explained (for the most part) by the mechanisms of the nervous system alone. Therefore, in my opinion, the argument that the nervous system and behavior are the same has become more strongly supported.
I think it is very interesting how based on negative feedback loops and variable set points, a good way for bodies to maintain homeostasis, some behaviors can be explained. For example, body temperature is normally around 98.7oC. When one gets hot, the body temperature rises above the set point and the person's body responds by sweating. The sweat eventually evaporates and cools us down. Similarly, when one feels cold (body temperature go below the set point), the person will involuntarily shiver so that heat is generated from the movement. However, for fevers, this type of behavior is not always exhibited. Sometimes, one will sweat, but feel chilly as a result. This is due to an increase in the set point - body temperature - where sweating will bring the body temperature below the new set point and cause the chills. So through this type of mechanism of the nervous system a number of behaviors can be understood, and in this respect it seems as though behavior is the nervous system. (But I wonder how/what causes the set point to change - increase or decrease - automatically.)
More compelling evidence for the argument is the presence of 'you' in the nervous system and how it relates to certain movements. The two main categories of movement are involuntary and voluntary. Involuntary is described as those actions which can be done by the nervous system, but not by you (like the sweating/shivering mentioned above). Furthermore, voluntary can be done by both the nervous system and you. However, it is not possible for you to do something while the nervous system cannot - there is no such thing. Even when I think about conscious and unconscious behavior, it seems as though conscious behavior can be due to the nervous system and you, as well as by just the nervous system since it can be either voluntary (i.e., walking) or involuntary (i.e., reflex). And unconscious behavior is involuntary, but again there is no behavior that results from you, but not the nervous system. Therefore, it seems as though you is a component or subset of the nervous system. In other words, accomplishing movement must be done in conjunction with the nervous system, but not necessarily with you. So it has been demonstrated that the nervous system is required for some behaviors, not you, lending more evidence to the argument.
Am glad you increasingly see behavior as emerging from nervous system processes, and your choices of examples are good ones (though you could write a little more compactly in explaining them). Why though do you personally find these examples particularly compelling? And what sorts of additional phenomena would you like to see explanations of in terms of nervous system function? The question I'm asking, in a sense, is how all this relates to the sense of what behavior is about that you specifically bring to the course. PG
Last week in class we addressed the nature of walking. The question arose as to whether or not this behavior is voluntary or involuntary. Although many of us admitted that we found ourselves in situations where we questioned why and where we were walking-- as well as the mere fact that individuals are not always conscious of their walking-- does not imply that walking is an involuntary action. For, if we want to stop walking at any particular instant we can and at any point in our stride. It appears that certain behaviors which are repetitive and common have evolved so that they are not in our consciousness. But the problem arises with certain behaviors like swallowing, and blinking. For though we will blink even if we don't think about if for an entire day we can nonetheless produce the physical movement of a blink on demand. Swallowing is another example. Few of us ever think about the action of swallowing but if told to swallow we can. Does this mean that swallowing can be either voluntary or involuntary?
Perhaps our tendency to characterize all behaviors as either voluntary or involuntary is a hallmark of western rationality and tradition rather than an accurate representation of bodily processes. The phenomenon which was explored which relates to spastic paralysis--in an afflicted individual who has apparently lost voluntary control over his arm motions, can, when influenced by a ball thrown at his head, block the oncoming projectile-- is extremely intersting. This seems to suggest that the nervous system retains information and the knowledge of how to perform certain behaviors. What appears to be lost is that part of the nervous system which links our cognitive processes including emotions and desires to other parts of the nervous system. If this bridge between emotion and motor responses could be traversed many advances might result.
Like what? Because that's sure the direction we're going. Indeed, part of what we were talking about was precisely the notion that dichotomizing BEHAVIORS into voluntary and involuntary is actually wrong: many behaviors, as you say, can be done either voluntarily or involuntarily. Which then implies (presuming the equivalence of brain and behavior) that there is some difference in nervous system activity, indepedent of the behavior performed, which distinguishes between voluntary and involuntary. And if we can specify that ... then? PG
The idea of where are "you" in the nervous system seems really difficult to pin down. From what we have been told, there are not that many behaviors that "you" can do completely voluntarily; in fact, just the demonstration wherein you attempt to move your eyes steadily and slowly showed how we cannot completely control our movements for when "you" think about moving your eyes steadily, the movement is jerky whereas when you just let your eyes watch/follow the movement of something else, the eyes will move smoothly. This fact makes it appear as if, in general, most behaviors happen "naturally" or involuntarily, sort-of a reaction to what is happening.
What makes this notion of "you" in the nervous system an even hazier prospect to consider is the philosophical questions of what is "you" as well. How exactly are "you" thinking about moving your eyes? What causes this concious decision to move your eyes? It is really at this point where I become completely confused about the nervous system. The fact that someone who is partially paralyzed cannot think to cause their arm to move yet if a ball is thrown at them, their arm might automatically react to stop the ball is strange because basically as humans we assume that "how we think" is the most important aspect of our behavior/movement. Because we are supposedly elevated organisms, humans believe that the "you" in them is the most important aspect to the nervous system yet so much happens without that "you."
This might be stretching the idea a bit but does a dog have the same sentiency/self-awareness that humans seem to have? Do dogs ever think about what makes the "you" in them? It seems very possible we could exist and go about and do things without this "you" or this so-called self. At the same time, life would probably be boring since there would no longer be the individuality of people; speech would also be minimal since every action is just done automatically. Is what makes the "you" the fact that "I think therefore I am," even though what you "think" about does not always result in the action you hope to perform? However, the fact that you are thinking says that there is a you. To decide what exactly "you" is just seems impossible since the more I consider it, the more puzzled I become.
Thanks. I couldn't have asked for better evidence that some things we're talking about are getting across. Yes, indeed, the observations raise very real and very interesting questions about what one means by "self". Among them is whether it is really appropriate to assume that what we think is the most important part of who we are, and whether dogs (and other organisms) experience a self in the way we do. Puzzled (but obviously thinking about the whole thing) is fine for the moment. We'll come back to some of the broader issues several more times in the course, and see whether it all becomes less puzzling. PG
The "I" function is only a small subset of the nervous system. This statement seems contrary to the belief that a person controls his of her own actions. If the nervous the system is determining the majority of our reality and generating output independent of the "I" function, what happens to notion of individual self- determination ? It is difficult for me to give up the belief that "I" have almost complete control of my own behavior. The importance of individual responisibility for one's actions has always been strongly emphasized both by our national ideology of meritocracy and our legal system. It makes sense that the nervous system controls actions which seem automatic- for example,walking or breathing. It is more difficult to understand the limited role of the "I" function in behaviors which involve contemplation and are of greater significance. For example,is criminal behavior part of the "I" function Do we blame it on twinkies or neurons?
How is the idea of attributing the vast majority of our behavior to neurological activity different from ascribing a large percent of it to environmental or social influence? I feel that the society plays a very significant role in output. You talked about trying to give your twins similar experences but that thiswas impossible because of differences in the nervous system- the role of central pattern generators and collary discharges. But, what about the difference social expectations placed on your daughter and son and their impact on their perception of reality and output? I think that these questions will be answered as we explore how the organization of the boxes depend both on genetics and experience.
Not sure we'll answer them, but do think they are very much the sorts of questions we need to be thinking about. Of course, society and experience plays a significant role in the behavior of individuals. So too do their genomes. All of which (genome, experience, culture), it seems increasingly clear, do so by influencing the structure and function of the nervous system. The question is how does all that relate to the idea of "individual self-determination" and to personal responsiblity? Particularly in a culture like ours which, as you say, puts such a high premium on these things in a variety of different ways. The issue, of course, is your "ALMOST" complete control. Our culture does in various ways acknowledge instances of diminished personal responsibility, though without a clear logic for doing so. Ideally, what better understanding the nervous system will do is not to make personal responsibility disappear, but rather to make more sense of both the limits and the potentials of individual responsibility. Let me know whether we get there by the end of the course. PG
okay, well i'm not sure how to answer this question except logically, which is probably not the kind of answer you're looking for. but since we argued earlier this semester that the brain=behavior, i guess the same argument can be made that the "you" is the brain. since behavior all stems from the brain, we can say that the "you", which is what our behavior makes us, also comes from the brain . when we flex or extend a muscle, we say that "we" want to move it. so we're asking, what does that "we" stand for? signals come into our nervous system, go through all kinds of neuronal channels (in the big box) and carry out an appropriate command. so if OUR brain and our nervous system are telling us what to do based on the input that comes into our brain and our nervous system, then isn't that "us"deciding what to do? the sensory input coming in isn't "us"- it just gives us information that we may or may not use. for example, input may tell us to do one thing and we may decide against it and do another. of course, our decision to do the other thing is based on different input, but still, it is our brain and our neervous system creating the behavior that is "us". also, any given input may effect different people differently, which helps to say that the "you" isn't the input we get. if we behave differently, the "you" must be the thing that is interpreting the input differently.
Interesting. You don't think I'm logical? Anyhow, I agree that there is a difference among individuals which affects how they process input, and that that contributes to individuality. But I suspect that YOU are unaware of most of that, just as you were unaware that YOUR brain makes up things which you're seeing. Which is to say that individuality is not in fact the defining characteristic of the kind of you which is sometimes but not always present when you move. How are we going to deal with THAT kind of "you" in terms of the nervous system? PG
"Voluntary and Involuntary Behavior as a Part of You"
If one follows the movement of his hand with his eyes, the eyes will travel in a slow, smooth movement. If the same person is then asked to move his eyes back and forth without the guide of his hand, the eyes will not be able to travel in the same manner as noted in the above experiment. Thus, the nervous system, in conjunction with reafferent signals, is capable of causing the eyes to move in a steady state, while a command from "you," without the traveling hand, will lead to short, sharp eye movements. There is a central pattern generator underlying both movements, but the reafferent signals lead to greater precision, suggesting that behavior does in fact evolve considerably from the outside world.
Voluntary behavior is correlated to input from "you," while involuntary behavior is correlated to the nervous system. Within this continuum, though, "you" cannot perform or function outside of the nervous system. With this evidence, "you" must be perceived as a subset of the nervous system. (I am not sure about this next assertion, but does it explain the you vs. nervous system argument? Do CPG's correspond to "you," while reafferent signals in conjunction with CPG's correspond to the nervous system? Is the nervous system thus "better" then "you" because it does heed reafferent signals?)
The manifestation of "you" implies the voluntary issuing of a command in a manner that elicits a behavioral response. Interestingly, "thinking" about the action you are about to take, be it a step or a verbal utterance, is a rare path to output. When one does try to direct or guide his behavior, such intense focus often interferes with a behavioral pattern. Perhaps, it is best to allow ourselves to follow the guidance and the destiny of our nervous system. The nervous system, then, can actually do things better if "we" stay out of its way.
A young child cannot move his fingers as separate units, instead, when asked to wiggle a finger, children respond by waving their entire hand. A pattern generator activates all the fingers and cannot move one finger by itself. As part of development, motor patterns are broken down into components to inhibit pattern generating sequences to cause more precise control of the components and the individual fingers. This control is needed for very precise movements, for novel movements, and for adaptive movements. It is through this almost evolutionary manner that a human being learns to survive, explore, and "compliment" his environment. I am still unclear how the breakdown of some of these pathways occurs in a universal manner. For example, eventually almost every child learns to operate each finger on an individual level. Is there a connector other than the genetic pool? What if "you" did not exert the need for hand manipulation, etc., would the nervous system overlook the behavior?
The "next step in the argument" being the one you've given? Let's see. Basically, we start with the proposition that ALL behavior (including our experiences of ourselves) corresponds to activity in the nervous system. If that is so, then the voluntary/involuntary distinction for movement must mean that movements can be made either with or without an experience of "self", and hence that an experience of self doesn't correspond to nervous system activity in general (or it would be there in both kinds of movements) but rather to seem particular subset of nervous system activity (which can be present or not in connection with other subsets of nervous system activity). Does that make sense? Then, of course, the question becomes what distinguishes the case of nervous system activity with an accompanying experience of self? For the eye movement case, there is a correlation with the presence or absence of reafferent dependence, but that doesn't hold in general. So, for the moment, let's keep it as an open question, and return to it several more times in the course before attempting an answer?
Interesting question about motor development and acquisition of individual finger control. COULD be something dependent on experience, but could also be "maturation", in the sense of something that happens over time because of genetic information irrespective of experience. I suspect that latter for this particular case, but presume you can imagine the relevant observations one would need to make to support this hypothesis? PG
Faced with the task of locating the "self" within the nervous system, I first wondered if this is not more of a philosophical question than a scientific one. Observations would indicate, however, that there are nervous system functions that we appear to control and others which function beyond our control. What separates the two and what defines what "I" am?
In attempting to answer this as good scientists, we begin with what we know. Behavior has been established to be patterns of action potentials. These action potentials originate and render effects in areas throughout the nervous system via complex systems of interconnected boxes of various sizes. Something happening in one area may affect something in many other areas and vice versa. Apparently, we have a degree of control over some of these areas and less control over others. Exactly where we have control and where that control ends seems hard to define in consideration of the close interaction and influence that the various boxes have. How can we isolate the "self" amongst these boxes when each box is so heavily dependent on many others for both it's input and output? Moving perhaps beyond science to intuition, I suspect that the "self" may prove somewhat elusive in terms of trying to contain it within one of our "boxes."
On bad days, I might feel "beside myself" or perhaps just not "myself." I might even take a year off to find "myself." Could these feelings be indicative of a dynamic "self" that takes on a particular form at one time and may evolve into something new at another?. Perhaps it's an indication of the particular boxes that we are exercising control over at the time. Or maybe on "bad" days the "self" is more subject to the control of boxes that usually don't govern it.
Whatever the "self" turns out to be, if we are correct in assuming that it can be explained in terms of the nervous system, then it will be subject to the limitations of the components of the nervous system. The "self," like behavior, will be limited to the abilities of patterns of action potentials driven through boxes within larger boxes. Can the emergent properties of such a system account for the complexity of the "self" in humans? I suspect that it is possible, just as our 100,000 or so genes can interact to produce the complex human form, so might our 10^11 or so neurons interact to form a complex personality.
You want to clarify your distinction between scientific and philosophical questions? Or, maybe more easily, that between science and intuition? In any case, the voluntary/involuntary observations seem to me to establish that the boxes are not in fact so heavily interconnected that anything any one does can influence and be influenced by any other. Were that so (and presuming that "I", like everything else, is a brain function), there wouldn't be a voluntary/involuntary distinction, right? I agree though that "not being oneself" and "finding oneself" raise some interesting problems. Peter Kramer's Listening to Prozac raises the same ones in a different context: many Prozac users report they are suddenly more themselves. I'm not quite sure how to deal with that, but we'll come back again in the course to whether there is a distinct "I" function box, how fluid it might be, and how that relates to "personality". PG
Voluntary behavior is that which is governed by one's own volition. the mere thought of being able to do something by your own volition is a consciousness of self that we have. Involuntary behavior is done without "conscious" deliberation. But that brings us to the idea of the subconscious, that which many believe to be the playwright of our dreams and the cause of mishaps like "Freudian slips" that we'd rather not attribute to our selves.
More often than we'd like to acknowledge, our conscious self takes takes a back seat to our nervous system (in sleep or some habitual actions), as in the example we discussed in class regarding walking. i.e. we don't always have to tell ourselves to walk. Nicole found a discrepancy in the dichotomy between "you" and the N.S., and I believe that may have a great deal to do with our subconsciousness. I believe she said: to some degree "you" ARE telling yourself to walk even when you are not consciously thinking about it. Those instances when the conscious self, "you", take a back seat to the N.S., perhaps it is not the N.S. alone that is responsible; some, maybe all of those things are controlled by the subconscious.
There is a chance that what we term as involuntary, or what we think of as controlled by the N.S. (not self, not "you") is the subconscious self. where does that stand in relationship to "you" and the N.S. Is the subconsious just another element of the conscious "you" or is it an element of the N.S. or neither: is it a third subset, a separate category from the two? When we speak of "you", do we mean to refer to your conscious AND your subconscious self? If so, an apparent discrepency would be that we don't usually view the subconscious as the cause of intentional behavior. If we group the subconscious with the N.S. instead, a discrepancy would be that, with medical knowledge today, we would tend not to see a case of tremors as a result of the subconscious.
Indeed, the voluntary/involuntary movement distinction is closely related to a distinction between conscious and unconscious, and hence implies a substantial reality to the "unconscious" (which is more or less appreciated/feared by different people). As for the relations among "you", "consciousness", "the unconscious", that's exactly what we'll want to explore further, from the starting point that they are all terms referring in one or another way to nervous system activity (right?). Which means, if I understand Nicole's point (and yours) correctly, that some nervous system activity somewhere can cause movements with an associated sense of "you" doing it, while other forms of nervous system activity can cause movements without an associated sense of "you" doing it. The latter presumably corresponds to what is meant by the "unconscious" or "subconscious"? PG
The nervous system has the ability to break down existing pattern generators and make new ones over time. This ability is responsible for quick, coordinated movements of athletes, dancers, musicians, etc. Common sense tells me that the development of the circuits must depend on repetition but some people are more able to make these circuits than others so inheritance must also play a role. A great athlete must also have the ability in the neocortex to inhibit a pattern circuit in order to respond to situations. If mechanical ability is inherited, then the child of a great musician could have the motor skills to be a talented surgeon.
If the too involve similar motor skills, and if one happens to get the appropriate genes from the scrambling involved in sexual reproduction, and if one also happens to have motivation and the right environment, and so forth. But yes, I too am pretty sure motor skill depends on something more than repetition. PG
It has been very interesting to learn about the nervous system and "you" for the past few lectures. It was thought provoking to hear that there were things that the nervous system did that "you" didn't know about, or that the nervous system did things better than "you" did. From this perspective, the nervous system and "you" seem like two independent entities in one person. Some times they know what each other is doing, and sometimes they don't. Where are they? Physically, I know where the nervous system is located in a person, but I don't know where "you" is located. I would like to say that you is located in the cerebrum, because it governs higher functions such as thought, reasoning, memory, judgment, etc., but I'm not sure.
Appropriate questions (as long as you keep in mind, as you seem to be doing, that "you" has to be found somewhere IN the nervous system). We'll get to some at least tentative answers (including the issue of whether it is specific to "higher functions" and whether one really wants to call those "higher"). Frogs do a pretty good job of reasoning, remembering, and so forth. PG
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