Nervous system architecture: from the output side II

Paul Grobstein's picture

Welcome to the on-line forum associated with the Biology 202 at Bryn Mawr College. Its a way to keep conversations going between course meetings, and to do so in a way that makes our conversations available to other who may in turn have interesting thoughts to contribute to them. You're welcome to post here any thoughts that have arisen during the course this week (and to respond to thoughts others have posted).

We've begun to move on from the building blocks of the nervous system to its architecture, as seen from the motor side:  distributed systems (no conductor), influences of the nervous system itself on interpretation of input (corollary discharge), reafferent signals and loopiness (exploration and "purpose"), the I-function as an inhibitor.    How do  these things help make sense of behavior?  What new questions do they in turn raise?

Lyndsey C's picture

I-Ponder the I-Function

I am really glad we got into groups today to tease out some of the class' chronic confusion about corrollary discharge signals and I-function responsibilitis. This is definitely not to say we came to any final conclusions, but I really do believe that at the end of each class we come closer to "getting it less wrong" (despite also creating a whole new set of questions that might appear on the surface to only add to the preexisting confusion!)

In following with this idea of an ever growing number of uncertainties, I have a few of my own questions that I wanted to post about. First, we mentioned in class today that "if we can think about what we can and cannot do without an I-Function, we can come closer to understanding what the I-Function is." Although this theory seems to be working well for the class in that we are slowly determining a definition of the I-Function and therefore extracting its primary functions (little by little) I am a little concerned about the order in which we do this. It seems counterintuitive that we would first determine the functions of a mechanism before describing what the mechanism is. Even though this order of operations is perplexing, i wonder if we are learning about it in such a way because it is in fact the ONLY way in which we can understand such a complex mechanism.

But actually, is the I-Function even all that complex? We have ruled out so many proccesses which we initially assumed the I-Function had control over (choice, perception of the self and others, etc). I am still left wondering, what does the I-function do? And if it's presence is not as neccessary for such processes as we once thought, is the fact that humans (and possibly some animals) possess and I-Function no longer the primary factor which sets us apart as cognitively superior?

We also spoke briefly about talk therapy in class today and how it has the ability to adjust expectations and processes of the nervous system. How does this occur? In other words, how does something that is not physical (talk therapy) alter something that IS physical (neurotransmitter relaease, for example). Is the I-function at all involved in this process?

What is the I-function?!?!?! So far all I've got is that it is one's awareness of the self and others and plays a role in the initiation of voluntary vs. involuntary action.

Jessica Krueger's picture

Better late than never...

In class, we arbitrarily decided that a choice constituted a selection between two options which were for all intents and purposes equal. What I tried (and apparently failed) to get across in class is that there is no way for any two "choices" to be absolutely the same: even temporal arrangement can constitute a history effect significant enough to alter the "reinforcing" capability of one behavioral consequence over another.

The slug who will not withraw when chewing is actually a pretty neat example of the above phenomenon. While foraging, and not chewing, there is nothing to support the probocis extending behavior, or rather, nothing to make such an extension with its while. There are significant chances for injury from predation, however, so with no reason to keep one's nose to the grindstone, withdrawing the mouth becomes the most "adaptive" manuever. When there is food, however, the schedule shifts - there is now a very good reason to leave one's proboscis out there, so there is a very good reason to evolve a CPG which can override a stretch-relfex input. So while the tapping scientist may control all he can to keep his nose-boppings topographically equivalent, they will never be the same to the snail because the contexts are different.

Further in class, someone mentioned how we can come to decisions when two options have the same probability of reward. This equivocation is supposed to be us weighing the options and deciding on the superior selection. I would argue that instead what we're witnessing is a search for that one critical aspect which would make one decision superior to another. As time mounts, the context changes, and eventually some characteristic would become significant enough to drive the "selection" one way or another. Adding time pressure to the system alters the context, and altering the context alters the choices - even if they hypothetically could be the same for a moment, the context would eventually change them in such a manner that one would appear "better" than the other.

Talking about making a decision always comes from an observer's point of view, even when we're viewing our own behavior. I don't think animals have that perspective with regard to themselves or others. Could the I-function be a heavily-specified homeostatic mechanism for detecting subtle shifts in our environmental contexts to help us behave in (presumably) more adaptive ways?

PS2007's picture


I would also like more explanation on the idea of choice. We talked in class about how you can send different outputs for the same input, but there still must be some reason behind why one output would be preferable at any given time over another. Is choice subconscious? I am still very confused about this, and hope we talk more about it in class.
AllisonZ's picture

I function

I, like many others, am confused as to our exact definition of the I function. It seems that even if we experience reactions rather than choice, the presence of the I function is what causes us to believe it is indeed a choice. So, as is asked above, what is the actual purpose of the I function? Also I find the question of whether animals also possess an I function intriguing. Many animals have complicated social systems, as well as a complex communication system. Primates are even more complex, and are even able to learn some amount of sign language and communicate with humans. Where then do we decide the I function ceases to exist? While there are certain animals we know are capable of higher thought, what about animals whose thought processes we simply don't understand? While we see the I function as choice, it is certainly possible that we too simply react, while the presence of an I function causes us to think we have made a choice. I think it is possible then to think that other animals also possess this function to different extents, but it is not observable because scientists merely see reactions.

Rica Dela Cruz's picture

Last week we discussed the

Last week we discussed the reasons for pain and how it is a way of reconciling corollary discharge information. We also talked about the I-function. I'm just wondering if the I-function can also be a reason for feeling pain. I was told about a type of malfunction with anesthesia where it does not fully work for some patients so they are conscious during surgery. They are able to hear the doctors talking, feel pressure and in some cases are even able to feel the extreme pain of the incisions and movement of their organs. However, the patient is unable to move or tell the doctors what they are feeling. I found an article about it: How is this possible? Because the patients are conscious when they feel the pain, does this mean the i-function does have a part in pain and it is not just the corollary discharge function? This scared me since it was also mentioned in class that it still is not fully known how anesthesia works. 
K. Smythe's picture

Choice, reaction, and their relation to the I-function

I found our discussion of choice vs. reaction and the relation of these to the I-function really interesting.  I think that distinguishing between choice and reaction is really difficult, borderline impossible from an outside perspective.  I like to think of my own decisions as choice because I am the one who "chooses" and associatively I believe that other humans like me feel the same.  However, to try and be totally subjective if I were studying human behavior I’m sure it would be possible for me to find complex patterns and call what we think of as decisions reactions.  We call them decisions because we see all the alternatives and “weight” the outcomes in our own subjective minds.  I’m not sure whether I think the I-function is necessary for one to make a choice (versus a reaction) however I am also not entirely clear how to define and distinguish the two.  Couldn’t the I-function, or more precisely the need for the I-function to make “choices” actually be a more primitive, less evolved mechanism?  One could argue that the I-function is simply a complicating factor, and that it is in fact not essential for the decision making process but may even hinder or complicate it with irrationalities or randomness.  Wouldn’t it be evolutionarily smarter to simply “react” as reaction implies an evolutionarily adaptive action?  Couldn’t the I-function simply be a complicating factor that we have yet to remove from the decision making process but which other organisms have done away with in order to streamline the mechanism by which decisions or reactions are made/occur?


EB Ver Hoeve's picture

Purple Monsters with Green Faces

Last week we began to address schizophrenia, however, I have several unanswered questions. I have always been interested by schizophrenia and its implications in behavior and I feel that this is the class in which we can discuss it in a more meaningful way. At a very basic level we discussed how some part of the NS, which tries out things to say, normally sends a signal back to the I-functions saying, “ignore this”. As we discussed in the case of schizophrenia, if that corollary discharge was missing, we might begin to have auditory hallucinations.
But auditory hallucinations are many times combined with delusions and/or visual hallucinations. How are these separate disorders related and grouped under one name? Does the auditory hallucination cause the visual?
Another question that I think is really worth discussing is, why are the auditory hallucinations and the visual delusions typically morbid and scary? Instead of seeing purple monsters with green faces and hearing voices that tell you to kill, why don’t you see/hear pleasant things? And I don’t know, is that just a generalization I have? And even if it isn’t true in 100% of all cases, the answer to that question opens up the discussion of environmental factors. With symptoms of schizophrenia typically developing in early adulthood, how/does the environment contribute to schizophrenia; does it have any affect at all?
And what about the genetics behind it: what do you mean exactly when you say that the corollary discharge loop is missing. Was it ever there? And finally, last semester in Developmental Bio, we briefly discussed a possible linkage between cat litter and pregnancy as a possible cause of schizophrenia (I think this research is being done and the UChicago), have you heard anything about that?

gflaherty's picture

one mechanism for jet lag...

            Melatonin is a hormone that is secreted by the pineal gland, which is found in the brain.  Its function is to regulate and maintain the body’s circadian rhythm, which is a roughly 24-hour cycle of physiological processes that the body endures.  A large part of this circadian rhythm is regulating a human’s sleep pattern. 

             Melatonin is activated by lack of light and the secretion of this chemical induces drowsiness.  And, of course, light inhibits the secretion of melatonin. 

            After our class discussion on jet lag and the response the body has to traveling through time changes, I thought that this would be a relevant process to discuss.  Because this chemical’s regulation is dependent on light and darkness, abnormal exposure to light can alter the body’s natural clock. This is a perfect example of the Central Nervous System interacting with another major system in the body, this being the endocrine system.

            Interestingly, melatonin can be taken as a dietary supplement that people can use to regulate their sleep patterns.  It is often taken by those who suffer from sleep disorders.  

Sophie F's picture


If we can accept that pain is the nervous system’s method of reconciling corollary discharge information and sensory information, what of emotional tumult? Is there a place in the nervous system where a mismatch between expectation of behavioral output and input coalesce to generate anxiety or sadness, etc. How is this pattern of behavior “created” or “reconciled” within the brain? As with the knee-jerk reaction in a physical sense, is there a corresponding movement within the nervous system to return the organism to emotional homeostasis? Is this, too, purposive? If the knee-jerk reaction resists being altered by the nervous system, do other behaviors that don’t enhance functioning of the species (which is, of course a subjective determination) also resist change? If one develops depression, for example, does this, re-establish a feedback loop that becomes self-perpetuating or a variable set point of sorts? Does the I-function intervene or is this all apart from the insertion of “self” into the mix?
Simone Shane's picture


A bit further up in the forum there was discussion about meditation and it's effects on the body and possibly on corrilary discharge signals. In my abnormal class, we are currently talking about how meditation and just being "mindful" of your surroundings can not only improve your mental health, but your immune system as well. I wasn't so much thinking of the meditation as a way for your I-function to better "conduct" corollary discharge signals, but for corollary discharge signals to be in sync. Here are my thoughts: if through meditation and mindfullness you become more aware of your experiences, emotions, and senses, perhaps the I-function is now just more in sync with the sensory corollary signals it was receiving? That is, the I-function now experiences these experiences just as the sub-conscious systems do and therefore the two signals agree. I was thinking that this could be beneficial b/c of the whole motion sickness idea where you feel ill when what you perceive and what you sense are different. Maybe the immune system workds better with meditation because what the sensory system experiences is actually in tune with what the I-function perceives. I realize how much of a stretch this is, but does anyone else have any ideas about why this may happen?

Also, I just wanted to agree with everyone that our definition of the I-function should be delineated much better. For example, earlier in the forum someone had mentioned theory of mind, which is the ability to represent others' thoughts. However, the I-function seems to me more focused on representing one's own thoughts. Now, from everything I've ever heard, non-human animal do not have theory of mind. However, I don't know about their ability to represent their own thoughts. So, if the I-function necessarily includes theory of mind, animals may not have an I-function, but if it is not necessarily in the definition, we cannot make this conclusion. A good constructive definition is needed to settle this matter and many other possible ones.
maggie_simon's picture

Puzzling Plantar Fasciitis and the Perception of Pain

I was very interested by our discussion Tuesday of pain perception.  I have a seemingly chronic pain in my feet caused by plantar fasciitis.  Plantar fasciitis is when the plantar fascia (a ligament that runs along the bottom of the foot attaching to bone at the ball of the foot and at the heel) becomes inflamed.  Inflammation of the plantar fascia can result from not wearing the properly supportive footware, having very high arches, or having very flatfeet, being overweight, from old age, or simply from overuse.  That pain in the bottom of your foot after a long day of being on your feet in dress shoes?  That is your plantar fascia acting up.  Many people experience this sort of short-term pain of their plantar fascia, but with rest the inflammation often goes away within a couple of days.  The physiological cause of inflammation is somewhat unknown; the explanation that I have heard most often is that micro-tears in the plantar fascia are to blame.  The more interesting concern is why does it become chronic in some people (that is, why do they continue to feel pain even when their feet are no longer inflamed)?  Again, this is a question whose answer has not yet been determined.


I have had plantar fasciitis for just about three years now.  There are three ways that I have come to gauge the state of my feet with respect to plantar fasciitis: 1) by how much pain I feel when I am on my feet 2) by how inflamed they seem to be (I find that when my feet are inflamed the pain that I feel is more exhausting and more tender then the pain I feel when they are not inflamed, so I know that my feet are inflamed when I feel this pain, and I also can tell because they will feel hot to the touch and somewhat swollen), and 3) by how thick the plantar fascia seems (supposedly the more thick it is, the more scar tissue and the less thick, the less scar tissue; so a thicker plantar fascia means that my feet have probably been inflamed fairly consistently for a decent amount of time).  When I first got plantar fasciitis, my feet seemed to be inflamed almost all of the time.  For the past six months, I would say that they have actually been rarely inflamed.  The regular pain, however, has been with me every single day of these past three years anytime that I am on my feet whether my feet are inflamed or not. 


It is only when I have bouts of inflammation, however, that I notice that my plantar fascia becomes more thick.  When there is no inflammation and I am just experiencing regular pain, the plantar fascia does not seem to be getting thicker, and often becomes less thick over longer periods without inflammation even though I am still experiencing pain daily.  This seems to suggest that inflammation is causing the damage (the increasing in scar tissue) to take place, but that the regular pain is not causing this damage.  So, pain from inflammation seems to be pain that comes from sensory signals telling my brain that there is something wrong in my feet and actually having something be wrong in them (inflammation causing scar tissue build up).  Why, then, do I still feel pain when there is apparently no inflammation and the scar tissue even seems to be diminishing? 


The way in which corollary discharge plays a role in phantom limb pain illuminates one possible answer in my mind.  In class we learned that pain such as that associated with lost limbs can be caused by a disconnect or contradiction between the signals the brain receives from sensory input and the signals it receives from corollary discharge input.  We also learned that nothing in the nervous system or brain is “hard-wired” because even central pattern generators can change or adapt.  Therefore, perhaps during the initial couple of months of my injury when my feet were constantly inflamed, sensory and corollary discharge signals were telling my brain that my feet were inflamed.  By the time that the inflammation had been eliminated, the corollary discharge signals had become adapted to sensing a certain constant degree of inflammation.  Then, while sensory signals are no longer sensing inflammation, the corollary discharge expects this degree of inflammation any time it realizes I am standing or am putting weight on my feet, and upon not sensing it, it tells the brain that something is wrong and the brain expresses pain.  Although this is just a hypothesis based on our discussion in class, it is exciting to think that maybe my feet are healing even though they don't feel like it, and that one day perhaps the pain will be gone as well when the corollary discharge adapts back to its original state sans inflammation.

Emily Alspector's picture

More on Dreams

I think the posts above regarding dreams are really interesting. I had the same thoughts in class on Thursday. If auditory hallucinations in schizophrenics has been attributed to low levels of corollary discharge, then when we dream do our levels of discharge decrease? This would make sense since discharge has been associated with input and many of our sensory inputs are altered when we sleep. However, I'm not sure I agree with Madina in that we don't know who we are when we dream. As far as auditorial perception goes, that is probably an input that is altered when we sleep, explaining why it takes longer to answer when someone calls your name than when awake. I do like the idea of I-function on standby, though. When we dream we sometimes see ourselves from a third party perspective (at least I do) but when I'm watching myself in my dream, I'm still aware of my self. I would be curious to know if there is any link between I-function in dreams and being unable to die in our dreams (since it's not something we've experienced before). I'm not sure if that's been proven, but it's something I've heard and it makes sense. Where do I-function and experience overlap?

I also want to review the reafferent loop, its function, and its relation to corollary discharge levels.

I'm worried that our conversation is pulling us away from the idea of the "mind," since I-function seems to be becoming less and less impressive or necessary. However, as someone who is still on the fence of dualism, I want to make sure we are aware of all of our options and don't just dismiss the idea of dualism because I-function is not as important as we previously thought. The idea that I-function is not necessary for decision making does not entirely convince me that it is completely irrelevant to the process. Along the same lines, we were discussing choices and behaviors, and, while it is important to look at simple behaviors like clapping or any output in response to two simultaneous inputs, we have to remember that there is so much going on inside our brains when we make decisions that it might not be comparable. If choices are made based on the I-function (which I believe it might be), why can't the I-function just be another pattern generator? or that which all generators refer back to? In terms of risk taking, competing pattern generators would look to the I-function (or personality of the self), in order to determine which generator "wins out" in the end.

Angel Desai's picture

What is the I-Function

This discussion of exactly what consitutes the i-function is really complex, and something which I hope we will continue to explore in the coming weeks. For me, I was under the impression that the i-function represented our self-awareness or more literally, what we percieve to be the "Self" If the Self encompasses our personality, our desires, our physical ties to the external world, then it would be difficult to imagine the i-function as merely another cpg. If we were to continue with this stream of consciouness however, could we posit that the i-function is a composite collection of multiple cpg's that are united in a way which is different from the rest of the nervous system?
mkhilji's picture

I found the idea of

I found the idea of corollary discharge being related to possible eating disorders very relevant to my last webpaper about body dysmorphic disorder (BDD) which my paper goes on to discuss how this disorder acts very similarly to over compulsive disorder (OCD). BDD is a mental disorder that involves a distorted body image. It is diagnosed in those who are obsessively critical about their self-image even if to everyone else there is no noticeable disfigurement or defect.Bringing this in to connection with corollary discharge, perhaps those individuals with this disorder have something wrong in their corollary discharge. The findings discussed in my webpaper suggested dysfunction in a 'circuit' or 'loop' connection between areas of the brain. For example if someone is tweezing her eyebrows with the intent of removing all the stray hairs from her original shape, through corollary discharge that individual is able to decide when she has tweezed enough--however when the corollary discharge is dysfunctioning the person may not receive the signal to "stop" or of satisfaction with the shape of her eyebrow--and so she may continue to tweeze away until no hair is left.

Another part of last weeks discussion that I found very interesting was the idea of losing weight. It was mentioned that our body has a set body-weight---and so if one attempts to lose weight till they reach their goal weight they may be able to accomplish it temporarily as they are conscious about it and are able to override the i-function by concentrating on their weight. However once that concentration is broken then that individual will gain back the weight lost--does this mean that weight loss is more about concentrating on your goal weight and about mentally feeling skinnier rather than regular exercise and a balanced diet?

Zoe Fuller-Young's picture

I think that the problem we

I think that the problem we have all had with finding a defiintion of the "I" function is because we all understand it as a different kind of "box." For me, the I function is our control, perceived or not, over our behavior. It is the box that we constantly discuss in class and feel we have not concluded quite yet, such as free will and desicion making. My opinion in the beginning of class was that regardless of whether or not other animals of varying capacities have an I function, but that humans seem to contain a particularly large I function.

As a few discussed above, we know that humans have the capacity to control certain behavior that is perceived as natural, or reflexive. Therapy and meditation can teach us to change our thinking patterns and ways of interpreting the world. Perhaps this does not mean that we interpret input differently, but rather we have changed our CPG or corollary discharge. Recently I heard that the Yoga instructor at Bryn Mawr was in a car accident, and she says that in the split second before the accident occured she realized it was going to happen and therefore relaxed her entire body. Her car was totalled, but she walked out of the car unscathed because she had somehow worked against what seems a panic reflex, and relaxed her muscles. Does this seem plausible? What does this say about her I function, CPG, etc?'s picture

i feel you....

Yes, I, too. DOn't know exactly what that I-function is.

I think it is that little voice that comes on in your head when you want to do something or are about to do something. "I am going to walk. I am going to eat. I am hungry..." etc. Hence, its name, the "I"-function.

But how does this rope in with muscle memory?  Somethings, you don't order yourself to do.  You just do it.  Like what Molly said before about locking your keys in the car. You just tend to close the car door after you get out and if I function was really the case, then wouldn't you have been able to stop yourself before locking yourself out of the car?  The line seems so hazy and so complicated, I feel that I'm constantly questioning even my own thoughts....

So...I think we should have a uniform definition of "I-Function" and then move on, because I do not understand certain people's comments or arguements since I think we all have different ideas of what the i-function really is.


Rica Dela Cruz's picture

Like many, I too am still

Like many, I too am still unsure about the role of the I-function. Our discussions in class have led me to think that it is not as important as I used to think it was. Prior to this past week, I believed that it was the I-function that conducted most of what we did. I felt that our consciousness was our I-function and because we are conscious for most of what we do, our I-function is the reason for our actions. However, we concluded in class that there is no conductor of the nervous system at all and that our actions result from the coordination and interaction of our neurons. Is the I-function, then, just our thoughts? Or do our thoughts come from somewhere else in our nervous system? Is our I-function just the presence of being, to know that I am I? 

 I was also surprised to here in class that theI-function is not in charge of our choices. The example of the Pleuobranchaea (I think this is that animal's name) brought up this matter. The animal had the choice of snapping at you or not snapping at you for touching it. We learned that there was an interaction of neurons that is the result of the animal snapping at you or doing another action, such as chewing. This surprised me because I had always viewed choice as being something made consciously, especially for human beings. I am not sure if I do agree with this idea of our I-function not being part of our decision making. I feel that maybe the action of snapping made by the animal is just a reflex. I also feel that this animal does not have the same higher cognition that humans possess. Therefore, although opposed in class, I still do believe that I-function in humans have a part in choice. I think we might need to discuss this further. 

evanstiegel's picture

I was wondering if anyone

I was wondering if anyone has brought up hypnosis at all.  I originally thought that during hypnosis, individuals are unaware of their behavior. However, I was surprised to read in an article that individuals are "hyperattentive".  If this is true, then why are people so willing to follow commands when hypnotized?  What happens to the the I-function?  If anyone can enlighten me about aspects of hypnosis, I would greatly appreciate it.
Jackie Marano's picture

Motion Sickness, Blindness, and the I-Function

After our discussions in class this week I have been pondering the concept of motion sickness, so I decided to do a little research. The best information that I could find matches what we had mentioned in class, with just a few extra details. It appears that the exact nature of motion sickness is not entirely known, but that it seems to arise from a mismatch of various sensory perceptions in the nervous system, including visual sensations, sense of balance in inner ear, and sense of movement in proprioreceptors. In cases of car-sickness, sea-sickness, and related forms, the failure of complete communication between the three of these sensory mechanisms generates confusion in the nervous system, and thus results in what we know as motion sickness.

I continued to explore the various ways in which motion sickness might be further complicated. For example, are blind people more susceptible to motion sickness because they lack the extra visual sensory input to communicate the perception of movement (or lack thereof) to the brain? According to my research, there is no significant increase in the occurrence of motion sickness in those who are blind from birth compared to those with sight, as their sensory mechanisms have adapted to compromised sensory loss...But what about those who become blind later in life? Can they adapt too...or are they forever afflicted?

Additionally, I was wondering about the role of the I-function in motion sickness. I have heard many cases of passengers in planes, cars, and boats who develop motion sickness...but why do I not hear stories of motion sickness on stationary exercise bikes, ellipticals, and treadmills? While I am sure that this occurs to a certain extent, it appears that the sense of sickness decreases if the activity becomes less passive. I can admit that if I am a passenger in a car and I am trying to read, I will feel eventually feel nauseated. However, I can run in place on a treadmill, watch a stationary televison, and feel just fine. The high demand for televisions in the Bryn Mawr gym seems to suggest that my experiences are shared. So, is it possible that one who is actively engaged in manipulating sensory his/her own sensory inputs (visual, inner ear, prorioreceptors) has increased resistance to confusions within the nervous system? And on a slight tangent...if we often perceive ourselves as 'moving' in our dreams, why do we not wake up feeling ill? Might the I-function be responsible in either or both of these situations? I am not sure of the answer...

Jessica Varney's picture

Thanks for taking the time

Thanks for taking the time to look further into motion sickness and posting your findings for us all to share, Jackie.

I agree with you when you say suggest that "the sense of sickness decreases if the activity becomes less passive". While I've never felt motion sickness in a car, my best friend Jayme has terrible motion sickness whenever she's a passenger. I find it interesting that when Jayme is the one driving the car, she doesn't experience motion sickness at all. The concentration required to drive the car, and looking ahead and toward the horizon is also known to aid motion sickness, so I suppose this helps correct the discreptancy between the corollary discharge signals and input to the nervous system.

(An aside that I found interesting: dogs are also capable of experiencing motion sickness. :)
Margaux Kearney's picture

Motion sickness cont'd

I have always felt motion sickness when I am a passenger in a car (in the backseat). However, when I drive the car, I seem to experience no motion sickness at all. I can see how the concentration required to drive the car alleviates the sense of nausea. We have to focus on where we are heading and our surroundings (visual and sensory aspects). Why do I feel less nauseous when I am a passenger in the front seat? Also, in addition to closing my eyes when I felt sick, I used to wear little wristbands with a tiny marble that I would place on my pulse. This would alleviate some of the motion sickness. How does this work?

Madina G.'s picture

dreams and the I-function

I think you bring up a really good point about dreams, Jackie. I do think it is the I-function in that situation that is responsible for what we feel (or rather what we don't feel) when we are asleep. Otherwise, without an active I-function, we would never be able to differentiate between reality and dreams. It is the I-function, in my opinion, that makes us aware of when an event occurred during a dream versus in reality. What I find even more interesting, however is that the I-function is not always in a fully activated mode. That is, when we are asleep, we are not as aware of ourselves as we are, when we are awake (i.e. if someone calls your name when you are asleep it takes sometimes several times repeating before you are aware someone is calling you, whereas when awake it would only take one time). This suggests that when we're asleep, our I-functions are almost in a stand-by mode and can always come back to a fully active state, but I wonder what this means for people in a coma. Because they are unconscious, it is simple to say that they're I-function is removed, but many patients awake from a coma and their basic skills are restored. If someone is asleep and then wakes up, it makes sense that their I-function was just on stand-by, but how do you explain a completely departed I-function and its sudden reappearance in an individual?
Caroline Feldman's picture

humans and choices

The concept of choice was an interesting topic when we discussed it on Thursday. Whether we have free will or if forces beyond our control determine our actions is difficult question to answer. But increasingly, as genetic science leaps forward and neuroscience pinpoints the brain loci of "choice" and even morality, determinism has been winning out. Advances in neuroimaging, such as functional MRI scans, mean that scientists can now visualize emotions and even predilections toward violence. Recently, cognitive neuroscientists Frank Tong and Yukiyasu Kamitani reported in Nature Neuroscience that they could, essentially, read the minds of subjects with a brain scanner. By imaging neural activity, they could determine the visual patterns on which a subject was focused. Such developments have applications that raise significant moral issues. If MRIs can image our deepest emotions and even our thoughts—sometimes before we can even know them—can there really be free will? Can personal responsibility and neuroscience coexist?
Lyndsey C's picture


Over the past few weeks, we have spoken a lot about the I-function and many debates have risen around the fact that animals may or may not have an I-function. I think this all depends on our definition of the I-function which, unfortuantely, we haven't yet teased apart completely. But as I understand it, the I-function is one's sense of self awareness, and for humans it includes theory of mind, or the mental reasoning of the feelings and thoughts of others. Cognitively, children develop a theory of mind near 2 years of age. Dogs function at about the same level of intelligence as a 2 year old, or so I've heard (maybe that's an overstatement) but i often wonder if animals, or dogs in particular, possess a theory of mind. we have discussed this in the forum before about how domesticated animals express guilt or shame when doing things wrong, but for the longest time i was not convinced that animals have an I-function. i just assumed the simple explanation that the I-function is a higher cognitive mechanism that we posess and animals lack and this is what sets us apart as superior beings.

maybe i was wrong.

i am interested in animals' psychological processes. animal behaviorists basse their entire careers studying such concepts, so maybe i should give this idea a second thought. i came across an article which briefly mentions several examples of animals' psychological functioning. for example, it states that a birds often groom themselves, expressing self love, but when they are angry or frustrated they may pluck out their own feathers to express punishment. this idea is not entirely new to me, but i guess i hadn't given it much thought before. anyway, these observations lead me to reconsider animals' potential abililty to have a working I-function. now the question remains, what are the limitations of their I-function? and what are the I-functions' responsibilies for animals as compared with those conducted by humans'?

In class on thursday, we debated whether or not animals have the ability to make choices. if so, we also wondered whether or not the I-function was involved in the decision making process. the article i mentioned above seems to support the idea that animals have "thoughts, intelligence, instincts, and feelings" all of which are important for the decision making process. but i am still not entirely convinced that animals make choices. mostly, i would assume that animals' choices, if any, are related to survival. as humans we have free will and less constraining consequences of our choices, so not all choices are survival-related. are they? if i choose to paper clip my report or staple my report, there is no influence on my survival. (unless you're taking it really literally and you follow the theory that each move we make influences subsquent actions, leading us to an ultimate predestiny. ok, i dont really agree with that at all so i wont even go there!)

basically i just left class yesterday with a bunch of slightly irrelevant questions and felt the need to post about them. i dont know if anyone else is as interested in animal psychology or if anyone else has thought about animals and their presence/lack of an I-function, but if you do, please respond because i'd be really interested to read your thoughts!

mcrepeau's picture

Not just animals...and the emergent I function in Social groups

When we say "animals" exactly what animals are we talking about? The general term "animals" which we've used in class so far has bothered me for a while now, after all it is unfair and incorrect to divide all sentient organisms into human and animal. Just as a human may not be considered the same thing as a snail... a dolphin, an octopus, a squid, or a chimpanzee cannot be directly held analogous to a snail or a nematode. These "animal" are all creatures with acknowledged problem solving abilities and/or emotions and complex social networks---if any species have the potential to have an “I” function analogous to what we humans think of as an I function than these are your best candidates. Whether or not a snail has an I-function and the ability to chose in the self-reflective sense that we are constructing the concept of "to chose" in I have no authority to comment on (I am not a snail and thus do not have an accurate idea of a snail's perception of life...potentially limited or not). Perhaps versions of or something equivalent to the "I" function do exist in animals of so called "lower orders" in terms of the "I function" as an awareness or sense of self ( I mean a sense of self exists even on a cellular level....even white blood cells…something never considered sentient in the least can decipher between self and non-self....what shares the same antibodies and DNA markers and what does not) but perhaps they have developed differently in different organisms and as such are not readily recognizable to us as humans (they may not be what we think of them as at all in other organisms)

Going back to the idea of the "I" function as an emergent property....perhaps the idea of the "I-function" as being an agent of reflective...big-picture....cause-and-consequence choice and information processing is an emergent property of social living in which the survival of an organism becomes the survival of a group in which the group must function as one individual, in a sense, where all the members of the group must coordinate with one another in a coherent fashion in order for the group to function and survive (this calls for an awareness not only of self but of others and ability to recognize how one's actions affect not just the state of oneself but also the state of group at large---in evolutionary terms this is a smart way to play, the more members of a group that are taken care of and survive to reproductive maturity...perhaps at the cost of the lives or quality of life of a few others...ultimately the more genetic material is preserved---thus choices about whether or not it is advisable for one individual to, say, horde a food supply for themselves versus share the food source with dependents, or smoke in a crowded, poorly ventilated restaurant---you get a nice nicotine rush out-of it but put the three asthmatics sitting at the table next to you at a potentially fatal health risk---are all very relevant to the idea of choice and group living)---as for the choice between a paperclip and a staple...humans have taken an emergent property to an extreme....


Caitlin Jeschke's picture

"Group" Survival in the Individual and the Importance of Memory

I think that your "survival as a group" idea is very appropriate for describing the nervous system.  There are numerous parts of the body controlled by different CPG's that must constantly communicate via corollary discharge, in order to produce the particular output that is best for the system as a whole (ex: the snail will withdraw its proboscis when poked to avoid danger that would compromise the entire system, but not if this means abandoning an equally advantageous activity, like eating).  This communication is further supplemented by sensory information, which helps to refine the output pattern (ex: if some type of proprioception tells the snail that it has enough nutrients, it may "decide" that protection is more important than feeding after all). This entire process could very easily take place without the phenomenon that we describe as "awareness".  However, awareness, and particularly memory, can be extremely useful, as they can provide a means to, in a way, "override" or alter current output patterns via the introduction of output from an event that is separated in time from the current situation.  This "memory" is not something that is physically available for the NS to sense, and yet it is (at least for me) a crucial part of the decision-making process.  Perhaps one of the jobs of the mysterious "I-function" is to act as a CPG that stores and releases bits of memory when properly triggered, connecting the rest of the nervous system to reafferent loops from the past.

merry2e's picture


I am just wondering...are they really using perhaps an "I" function when pulling out feathers or are they just CPGs or CDs that have been aquired?

I am quite confused...

I personally have issue with animals having an "I" function or psychological functioning. Maybe I am really alot more egotistical than I realize and it is my issue thinking humans are much more "evolved" than other living beings...hmmmm...maybe I should look at that. Or maybe I should just stop thinking for a bit.

jwong's picture

In our clapping activity

In our clapping activity with the class last Thursday and on Tuesday, the issue of there being a single conductor was raised. If anything I think the idea of everyone being their own conductor is still very valid; everyone’s I-function definitely controls corollary discharge and thus helps render people being aware of the other movements, noises, and presence around them, regardless of their five senses. A person’s being aware has to do with their ability to react to those around them, and how they can control their reactions to those around them. I read an interesting article about songbirds and mirror neurons, a type of neuron that fire both when an animal acts and when the animal observes the same action performed by another animal. Known to be expert mimics, songbirds’ singing abilities result from their mirroring neurons located in the “high vocal center (HVC)” of their brain, where they react to specific songs using precise timing; this particular pattern of timing the nerve impulses are the same whether the bird is listening to song or singing them. This coordination of delaying motor signals is an example of corollary discharge, where the neural representation of the output the song being sung is programmed to compare with the auditory input of hearing the song being sung. This corollary discharge pattern is significant to the songbird’s ability to actually learn the song they sing and to recognize the songs of other birds singing in their same vicinity. Thus corollary discharge is important to introducing variability to the song pattern itself, an integral aspect of a songbird’s mating abilities. In this way, I think the corollary discharge pattern can be seen as being related to the I-function because it allows the songbird to have a sense of its surroundings and thus makes it more able to determine its current state. Knowing how to perceive itself in relation to its surroundings help to center the bird and is central to its ability to perform and function.

heather's picture

the h-sap 5000 processor

if i may use the ns-computer analogy, the 'superiority' of our species' computer might just be a more high-tech information processor and (maybe) some more storage space/RAM. we should come to terms with the fact that this is a possibility, while keeping in mind that the basic (nonhuman animal) computer models are 100% functional without all the bells and whistles...

often i think we are too complicated for our own good.


which reminds me....
does any other species feel dilemmas?

nasabere's picture

What good is the I-function anyway?

" often i think we are too complicated for our own good." thinking about the I-function, it seems to me that it's only role is to over-complicate things. We have yet to come across its definitive role in the NS; rather it seems to move in and out of activity as it pleases. Clearly, it's not entirely necessary for survival. What then, is the value of having an I-function, anyway?

Skye Harmony's picture

also confused about I-function, conductors, and hot coals

I'm also confused about the role of the I-function and how certain behaviors can occur with no conductor, such as merry2e's example of walking on hot coals without feeling pain. If the person isn't consciously using the I-function to somehow tell the rest of the nervous system to alter the corollary discharge/sensory input circuit, then how does this circuit get altered so the person doesn't feel pain? Does the I-function just help the person focus on other things so they don't notice the pain? I understand that a conductor is usually not necessary and the different parts of the nervous system communicate among each other with no one part in charge, as in the crayfish swimmeret motion, but in the hot coal example I'm not sure how we would describe the role of the I-function and explain the lack of pain sensation.
Margaux Kearney's picture

Confusion about the I function and hot coals

Like many, I am still unable to grasp the role of the I function and how an individual can walk on hot coals without feeling pain. I found this interesting article online ( that describes how a young boy from Pakistan could walk on hot coals and feel no pain. The scientists in the investigation looked at three families related to the child and found that none had experienced pain at any point in their lives. After extensive genetic tests, the scientists concluded that the boy and the other individuals all had an extremely unusual mutation in a single gene. The defect in this gene, SCN9A, disrupts the flow of sodium ions into specific neurons that sense damage. The mutation causes the first stage of the electrical signal to be lost, so the signal is unable to reach the brain. Could this be an explanation for the lack of an "I" function?

Tara Raju's picture

I am not convinced...

It just seems that ultimately we can hold something to the "conductor" position in every example that is brought up. The example of the system of government checks and balances was used but it can be said that the consistution is the conductor in that position and that in the hand-clapping activity somebody mentioned that the dominate/loud clappers helped create the uniformity. Using the hand clapping example, it seemed tha tif we didn't know if that were trying to create one unified sound then we wouldn't of accomplished the task so quickly. We were conscious of our actions and the outcome that they would have. Basically, I am not convinced that the "I" function is not serving as the conductor in most of our activites. But I also understand that CPGs and other components are work as well but to what degree are they influencing our actions and nuerons- to what degree to our controlled pattern generators, "I" function and all of those components working together. Which is the loudest in this symphony? Which is the quietest? Does it depend on the situation?
merry2e's picture

babble on ...

If pain can be understood as a mismatch between corollary discharge signals, than someone walking over a bed of hot coals can override the pain using their “I” function bringing the level of consciousness or perhaps unconsciousness (?) to a higher awareness of sensation (?) or duller (?) depending on which way you actually look at it, and therefore, the “I” function really could be seen as in control or the “conductor” of sorts (in this type of situation). So, therefore, in situations, like eating disordered clients, or schizophrenia or depression/anxiety, though there are biological processes involved (corollary discharges for example), I can also see where the “I” function and the use of therapy comes into play working on different parts of the NS/brain.  I like thinking about if I did not have an “I” function I would not be sitting here typing these words on Serendip.  And I feel like that gives the “I” a lot of power. But, then again, if I did not have CPGs and CD’s and such , I wouldn’t be sitting here typing, either. A wonderful symphony….
Jen Benson's picture

One of the issues raised in

One of the issues raised in class is that the behavior of choice may potentially be explained by central pattern generators which are activated in response to certain situations, with some central pattern generators serving an inhibitory role in suppressing certain responses in the presence of specific environmental factors, like in the example with the sea slug (?) with claws. This example was particularly helpful for me because it illustrates how the nervous system affects behavior in one respect by responding to environmental input. What the slug lacks, I think, that is present, in humans, however, is individual differences in personality, that can also affect choice. As I’ve written in other posts, some personality variables have been researched at length, such as neuroticism, openness, extraversion, conscientiousness, and agreeableness. People tend to show consistency in these variables over time, and such factors have been reliably linked to certain behavioral tendencies. Research into the roots of these individual differences (comparing twins raised apart and together) generally supports the view that roughly 50% of the variability in them is due to heritability, and 50% is due to the environment.
Another factor affecting behavior is the power of the social situation. A whole branch of psychology (social psychology) has illustrated how people’s behavior, thoughts, and emotions are intimately tied to the real or perceived presence of others. Perhaps the crab/slug(?) would behave differently as well in response to being bopped on the claws in the presence of other crabs. Maybe some central pattern generators are linked to specific social situations that activate them.
Both these factors that influence behavior, the social and physical environment, and genetically and environmentally shaped personality variables, also suggest mechanisms that can substitute for our current understanding of choice.
Caitlin Jeschke's picture

Drugs v. Therapy?

This topic reminds me of the discussion we had in class about treating disorders with chemicals (drugs) v. therapy.  On Tuesday, we talked about two different ways to treat pain in phantom limbs-either create some sort of sensory input (i.e. the reflection of a healthy limb) that tells the body that the missing limb is in fact OK, or alter the corollary discharge so that the pain that is being experienced matches what the body perceives the limb to be doing (someone mentioned that pretending to bang a missing foot on the floor helped to alleviate phantom pain in that foot).  Either way, the reafferent loop and the corollary discharge signals are made to match one another, and then the pain is relieved.  Perhaps drugs and therapy work in a similar manner. Introducing chemicals into the body can alter feedback/the reafferent loop.  If, as it has been suggested, the I-function is capable of strongly influencing corollary discharge (and I realize that this is a big if), then maybe a person undergoing therapy is learning how to use this influence.  Just as similar results are observed for both methods of phantom limb treatment, both therapy and drugs have been shown to be affective in the treatment of physical and mental disorders.  The huge amount of variability in NS structure between individuals can then explain why various treatments affect different people in such different ways.
Molly Pieri's picture

More on pharmacological vs psychological therapy...

In my research for my webpaper, an article ("Effects of Writing About Stressful Experiences on Symptom Reduction in Patients with Asthma or Rheumatoid Arthritis" in JAMA 1999;281:1304-1309 available for free on the JAMA website.) was referred to me by a friend which I think bears on the discussion we had in class about drugs v. therapy. The article describes the therapeutic value of journaling for patients suffering from asthma and/or rheumatoid arthritis. Patients of one group were instructed to journal their experiences pertaining to their disease while a control group did not journal. both groups were undergoing pharmacological treatment, but the group with also had psychological therapy (journaling) showed improved health over those who did not journal.
I thought this was a particularly interesting study. While we focused our discussion on what are considered primarily "psychological" disorders (depression, ADD, bi-polarity etc) this study focused on the benefit of psychological therapy had on primarily "somatic" disorders. For me, this really blurs the mind-body distinction.
Nelly Khaselev's picture

Hmm...maybe not?

Couldn't your I function though also be controlled or affected by corollary discharge? This would prevent someone from concluding that the I function is a conductor. After all the I function is still just another box in our nervous system. Perhaps the people who can walk across hot rocks are those with special corollary discharges in parts of their nervous system, so they don’t feel the pain and are able to walk across. Plus, although I completely agree that therapy can help people with anxiety, anorexia and other disorders, if the therapy does not fix the corollary discharge break or confusion then the problem cannot go away (assuming the these disorders are indeed controlled by something going wrong in the corollary discharge of the NS). If the I function was truly the conductor of pain or these disorders wouldn't it be much easier to help those with disorders. Why do some people respond to therapy better than others? and some not at all?
heather's picture


think also about the use of certain types of meditation in therapy (ie: cancer patients).

this therapy is designed to remove the patient from his or her own pain through "mental control." what if this is the effect of the i-function dominating input/output signals, causing the subject to be 'unaware' of other signals (specifically, pain)? isn't that conduction?

(obviously, i'm oversimplifying - there are more complicated physiological effects from meditation, as the above-linked page states in its discussion of the science behind the act).

i'd like to know why it works.

mcrepeau's picture

I function as a score editor v. score conductor

I don't know if the ability to filter out signals from the Nervous system would be considered a form of "conduction" seem more like selective editing if anything...after all the pain signals...the dummy light for the system that alerts everything else that there is some kind of input/corollary discharge mismatch is still on...those signals are still being sent so it's not as if the I function is controlling the production of or coordination of those signals; however, the signals are somehow being ignored by the "I" function so that we are either not made aware of their presence (even though we may still be receiving those error signals) or else are aware of them but are able to translate them into something that is non-imperative or non-threatening. Perhaps, some kind of CPG and/or corollary discharge units that make up or function in conjunction with the "I" function have been re-patterned (the box arrangement/coordination has somehow changed) so that pain signals of a certain amplitude, from a certain part of the body, etc. are inhibited from continuing into the "I" function proper or the signals are somehow re-assembled so that the mismatch appears to be fixed...perhaps missing parts between the input/discharge signals are fabricated (like how the brain fills in missing visual information from peripheral vision) and what is received by the I function is a combination of the "mismatch!" signal and fabricated information (which could be made up visual, auditory input etc, like we talked about on Thursday with he boxes in the brain that can generate auditory or visual information independently and when not understood by the rest of the brain as self-generated may be interpreted as actual sensory input form an outside source) which when read together make a complete set of coherent information.

Paul Grobstein's picture

on conductors and/or their absence

See Lyndsey C. and Mahvish.