Neurobiology and Behavior, Week 10

Paul Grobstein's picture

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

You're free to write about whatever came into your mind this week, but if you need something to get you started: how are we doing at this point in linking neurons and behavior?  with CPG's, corollary discharge, feedback loops (both external and internal), comparisons of expectation and input ... and an I-function that both excites and inhibits?

 

meroberts's picture

Trouble with corollary discharge in larger context

I still don't think I'm grasping the concept of corollary discharge. I understand (at least in the example of motion-sickness) that corollary discharge needs to "match" the sensory input to the N.S. in order to avoid feeling sick. However, I don't understand the role of corollary discharge in the larger picture.

Other than that, I don't really have any problem integrating CPG's and their own unique feedback loops. It makes sense that the I-function should be able to excite and inhibit based on different input to the N.S., even if the i-function is somewhat removed from the processing of this sensory input. It seems that much of the class shares some level of surprise in the auxiliary role the i-function seems to play in sensory input processing. If so much of this processing is going on before the i-function is even aware of it, then shouldn't there be another region/component of the brain that also excites and inhibits? This region/component could probably respond (in an excitatory or inhibitory manner) much faster than the i-function owing to the amount of time necessary to update the i-function of the neural mechanisms already at work. 

cschoonover's picture

Choice, set points, and negative feedback

 The experiment with the sea slug’s behavior choice (to withdraw its mouth or not) is interesting in that it shows how corollary discharge signals can influence what the nervous system does in response to input signals. For the sea slug, the input was banging on its mouth, and the output was retraction of the mouth. However, retraction does not occur if the nervous system is inhibited by the corollary discharge signals from the CPG that is used to grind its teeth. If this occurs, the mouth will stay out. Given this scenario, it is possible to account for aspects of choice using corollary discharge signals and CPG’s. However, I am not convinced that this is adequate enough to characterize what we mean by choice in human beings. It seems like there is much more involved than an inhibitory effect when we choose. For instance, when we are deciding what kind of car to buy, there are a lot of factors to consider: how safe is it? Is it fuel-efficient? Do I want a car that is fuel-efficient? Is it aesthetically pleasing? How much can I sell it for later? These are just some of the questions one might ask. If the sea slug module is correct, then where is the inhibitory factor in this decision? And what about those decisions that we make in a split-second, the ones that most people refer to as instinct? Humans make instinctual choices all the time, and they occur so fast that if there is indeed an inhibitory factor, it must occur at top speed. Right now, I seem to be having a hard time understanding how behavioral choice in humans can be explained in this manner.

On a different note, I had never considered the idea of set points and negative feedback loops in the nervous system or how much of our daily patterns are influenced by these. But this makes so much sense to me now, especially in terms of how the body reacts to disruptions/perturbations to its normal pattern of functioning. Our body’s response to fever is a great example of this: the body has a set point for temperature, but in the presence of an infection, this set point is increased to fight the infection. Although our bodies are warm/hot, we shiver because our body temperature is now below the new set point and it is trying to reach it. Our nervous system is acting in such a way as to adjust to the changing internal environment. This process however, is not in the realm of what the I-function can do. Going back to choice, there are choices that can be made in the absence of the I-function (i.e. maybe instincts), but there are also instances in which the I-function is necessary for explaining human behavior and choice. Maybe further exploration into the involvement of the I-function in choices outside of biological processes would help explain what we refer to as human choice, those decisions that are made every day that do not concern the functioning of our bodies. 

natmackow's picture

Set points determined by the NS, I-function and hormones

I found our discussion of set points in body temperature and weight to be intriguing. The idea that body weight is controlled by a negative feedback loop that opposes weight changes (bringing it back up or down to a set point) makes sense as far as how difficult it is for diets to actually work. In many cases people want to lose weight through dieting and they can, for a time. However, it seems that the i-function does not have as much control over this and that the nervous system ultimately brings body weight to a point where it feels the individual is stable, so to speak. As this set point changes when women are pregnant, I think it would make sense that the NS would alter the set point when individuals make healthy or unhealthy long-term lifestyle changes. For instance, I would expect the body weight set point to change for an individual who used to exercise once or twice a week and ate McDonalds frequently and who now goes on morning walks and eats frequent balanced meals.

Another interesting phenomena I’ve thought about involves individuals with hyperthyroidism who seem to lose weight despite the fact that they have not changed their daily routine or the foods they consume. In these individuals it seems that an outside force (from the NS/I-function), the thyroid, determines the set points for an individual’s weight, body temperature, and perhaps the balance of chemicals in the brain related to anxiety and restlessness. Irregularities in the ways these hormone-producing entities work seem to override the I-function and the NS in creating and maintaining a set point (hormone changes are also involved in the weight changes in pregnant women as well). Perhaps there are additional contributors to the maintenance of such set points? Or perhaps the thyroid and other hormone producing entities in the body can be considered a part of the nervous system?
 

Schmeltz's picture

Mental Tweaking of CPGs

When we were talking about pain on Tuesday, and the fact that the child only cries after it has been pointed out to it that there is injury, I was not very convinced that the child did not experience some element of pain prior to the acknowledgment of injury.  I was thinking that if I sliced my finger open, I would totally feel it regardless of whether or not I actually saw the open wound occur and I would feel it regardless of whether or not someone pointed it out to me.  Well, I was proven wrong.  I went to the Gunks this weekend to do some bouldering.  I was working out this problem - one of two boulder projects I have.  The move requires holding on with both hands to a sharp edge, fully extending both arms, placing the right foot on a small foot hold and smearing the left foot on some slippery slab and then throwing the left arm up to this hold.  Well, I was doing this over and over again, sometimes sticking it, and during one of my successful attempts I tried to throw my right hand to match up to my left.  I got it, then fell, but I was quite pleased with myself.  I went to get some more chalk and then noticed my right hand was covered in blood.  Apparently, the sharp edge had caused a flapper - a piece of skin had been torn off my one of my fingers.  I thought it was weird I did not even feel it, then suddenly my finger hurt.  It is interesting that I did not feel pain until the blood and the concerned look on my friends' faces suggested to me that I should feel pain.  Further, at the end of the day, I noticed additional scrapes, bruises, blisters covering my body that caused me no pain what-so-ever during the day because I was so focused on my two projects that pain was unfelt or unobserved.  I think that is interesting.  Perhaps we can shut off pain with sharp focus or perhaps we are adjusting our nervous system's response to pain in order to stick all these ridiculous boulder moves.  However, there is a point where pain is obvious.  You break a limb, sprain something, etc. pain usually follows instantaneously.  Seems like maybe there is a set point for pain.

So, we have been speaking a lot about CPGs and movement.  We acknolwedged that CPGs may be tuned and adjusted both physically and mentally.  Well, I worked very hard to physically tweak my CPGs yesterday in my attempt to send a boulder problem, and it just did not happen.  It could be another I-function interference or perhaps more modification needs to occur.  I have a mental score of the moves I need to stick in order to send this boulder problem and I have been playing them in my head since yesterday.  I am wondering if this mental recall will assist me in anyway when I get back to the project this weekend. This is my test for the week - to see if I can mentally tweak my CPGs. 

mleung01's picture

Setpoint and more on corollary discharge

The concept of having an automatic control system in our body is very cool. It is said that setpoint controls body weight and happiness just to name a few. But just how permanent are our setpoint? With all the medications and outside interventions that are available to us, can we break our setpoint and in a way reset it? On the other hand, if our setpoint is preset and unchangeable then everything about us has a limit. Granted the limit for each individual is different but once we exhaust that limit what happens then?

Another thought that came to mind relating to corollary discharge is dyslexia. It might not be related but I was thinking if our body could distinguish between self-generated and external stimuli and perceptions then what happens in the case of a dyslexic person? I would not say that I am dyslexic but I do have trouble distinguishing between my right and left. Even with external stimuli, such as someone telling me to turn left or right, my body naturally turns towards the left (left-handed) unless I put some thought into it. The same situation when it comes to shaking hands. I see that the person has stuck out his/her right hand and yet I still extend my left hand. I guess what I perceived was not being translated correctly. Does that mean my corollary discharge mechanism is not distinguishing what was mentioned above effectively?

 

Congwen Wang's picture

Set point, and bird songs

After our class, I'm interested in how the set points are set and adjusted. It makes sense to me that we have some kind of a set point for body weight, body temperature, etc - it's probably just one of the mechanisms for our physiological regulation. What I'm curious about, however, is how do our bodies decide the proper set point? I'm pretty sure there is a strong influence by genetics, but that doesn't explain how our bodies sometimes alter the set point drastically. Is there a specific location in our brain that controls the set point? Hypothalamus seems to be capable of controling body weight by regulating some important hormones, but still, to what stimuli does it react and change the set point? Also, for people with severe obesity, do their set points work properly? Is their obesity a result of a wrongly set set point, or of a set point failure, or maybe both?
Another thing I'm very interested in is the bird songs we discussed in class. As Professor Grobtein said, depending on the species, birds from sister species may or may not be able to distinguish the song patterns between two closely related taxa if they have no previous exposure to them. It really intrigues me because it reminds me of the paper I did on the greenish warbler ring species last semester. (A brief but very useful introduction: http://www.zoology.ubc.ca/~irwin/GreenishWarblers.html).  Since there are interbreeding zones between neighboring subspecies, it must also react to songs from its most closely related subspecies, so I wonder how do these birds learn their own subspecies' song. Or maybe those birds in interbreeding zones just randomly learn one of the two existing patterns?

emily's picture

Unconscious and conscious processing

I thought our conversation about unconscious learning was very interesting this past week. We concluded that unconscious learning in general is not just a template but that we have to use reafferent loops, put them into practice, in order for what was learned to become ingrained. This got me thinking about what we previously learned, that practicing certain actions cause those patterns of neuronal activity to become ingrained (piano playing, sports, etc.). In the case of such unconscious actions, we are programed to run certain reafferent loops, whether we like it or not. This may help explain "perfectionists", who have to do something right or in the right way so as not to feel anxious, and maybe even cases of OCD. A close friend of my has rather debilitating OCD...he has certain patterns throughout each day that grow harder for him to break the more he practices them. Is the psychological reasoning behind his OCD related todiscomfort in breaking certain conscious or unconscious loops?

 

Another thing that interested me from this week's conversations was the negative feedback loop of weight control vs pain sensation. It is funny that something which seems to be in our control, weight loss and gain is really not, as there is a certain set point that changes with age which we cannot deviate from without consciously thinking about it, while something that seems to not be in our control, pain, really has to do with our state of mind and is something we can have more control over. Both processes, negative feedback loop for weight control and pain sensation, can be interrupted or affected by conscious processing. I'm not sure if this is the best example, but my lacrosse coach told us that when her 9-month old son Jack, who will stand up holding on to a wall, falls down on his bottom, she and her husband will cheer and clap for him. His face may seem upset right as he falls down, but when he sees the happy faces and hears the reassuring cheers, he starts to smile and laugh. Jack's conscious processing of the positive reinforcement "gets in the way" of the pain sensation.

lfrontino's picture

Bird Songs/Clarifications

 I've been thinking about the subject of internal calibration processes and how birds have a genetic template for the songs that their species sing. A bird song is a type of reafferent loop where the bird needs to try out the song multiple times before it is able to perfect it. This is the same for human talking and other output patterns. 

How does this relate to other pattern generators? When a piano prodigy sits down to play, they don't have to practice a piece they have heard before they can just play it. Is there something special about their learning process that they don't have to make a loop out of it, rather they can just get it on the first try? 

Another point to bring up: I wanted to to clarify a question I had on the difference between neurotransmitters and hormones. Since both are chemical signals that are released in the brain and trigger some sort of response, I wasn't sure why they were classified as different things. After talking to Professor Grobstein and reading a bit about them, I think I can see the difference. A lot of it actually has to do with how they were researched. While neurotransmitters were associated with the nervous system, hormones were researched by scientists examining the endocrine system. Also, neurotransmitters are normally associated with signals that stay relatively local in the brain while hormones are known to travel great distances throughout the body. Still, these differences seem slight to me. It's interesting to think that if these chemical substances had been studied together, more similarities would have been made between the two and they could possibly have been grouped together. 

MEL's picture

CPGs and Set Points

I think that I am starting to understand the concept of CPGs better. The example that I found very interesting was the CPG for signature.  In the past, whenever I tried writing my signature with my left hand I noticed that, although it was messy, it did share many similarities with the signature written by my dominant right hand. It makes sense that this occurrence is due to the fact that there is a CPG that controls signature.

This week when we were talking about reafferent loops I found the internal set point for weight very interesting. I am a bit confused by this example. How does this set point exist? If a person eats more food that he or she normally eats then what does the body do with the extra calories in order to keep this person at his or his weight set point? Does this set point prevent tiny daily fluctuations in weight or does it prevent a person from losing or gaining a substantial amount of weight ? I am just a bit confused about this set point’s purpose and how it actually functions.

Lauren McD's picture

Set Points

Last Thursday, we dicussed the matter of set point in different, everyday examples. I have heard of body weight having a set point in the past, but I never understood it. Even now, I'm still a little confused by it. If we eat less or exercise more, our weight will definitely go down. In contrast, I doubt eating a significant amount of bad food choices would allow you to remain at your set point. So is a set point the tendency for a weight to hover near that certain number? Maybe it is easier to adjust the body weight towards the set point, rather than away from it? Because it is certainly not a distinct number that we are tied to. Besides pregnancy, what else adjusts this set point? Do we have any control over adjusting it? I have heard the term 'set point' used only when referring to weight, but I had not heard it used in other examples discussed in class, such as shivering with a fever. This occurs because the body is trying to raise the temperature to the newly established set point. Did a virus or bacteria cause this set point adjustment? How do set points change? Furthermore, how are set points determined? What makes one person have a higher set point for weight than another? I'm assuming it's genetic, but what specifically? How does something that's genetic change due to other influences, such as pregnancy? This idea of not having control over something as close to you as your own weight is intimidating, and not greatly believed in our society full of advertisments of lowering your body weight.

Saba Ashraf's picture

Reafferent Loop/Set points

Going over the reafferent loop in the nervous system definitely clarified the behaviors exhibited by many organisms such as birds. I found the example of the bird songs particularly interesting because of the fact the birds were able to evaluate their singing against their own perception of what the song should sound like. Not only did they need to hear the song, but the birds also needed to practice it themselves. Humans are very similar in the way that they not only need to be exposed to language, but also need to speak it. This reminds me of the fact that certain people can sit in class and hear the instructor talk, yet unless they go over the material on their own, they don’t have much understanding of the material. In this case, being in class will only help if the students also put more time into understanding it on their own. This relates to the fact that certain birds can hear their specie’s song at a young age, but if the song doesn’t crystallize, the bird won’t sing the correct song. Also, the fact that body weight is controlled by a negative feedback loop and that one’s set point for body weight changes as they age makes a lot of sense. I have always realized that people have gained a significant amount of weight from when they were adolescents, yet I never really known why.  However, I was wondering about how the set point for body is actually changed and whether it was related to the physical activity and diet a person eats?  

egleichman's picture

some food for chemical thought

Our conversation about the ineffectiveness of dieting raised some questions for me, mostly chemical.  A UCLA study exposed the following findings on dieting after noticing the strange trend that existing research rarely followed up on dieters beyond six months:

" 'We found that the average percentage of people who gained back more weight than they lost on diets was 41% (...) In each of the studies, a third to two-thirds of the subjects gained back more weight than they lost.'

Does this mean that most of the people in the studies actually lost weight and kept it off? No, Mann says.

'This is actually bleaker than it seems -- even though most people would find that 41% number to be pretty depressing," she says. 'We have strong reasons to feel that this number underrepresents the true number of participants who gained back more weight than they lost.""

This seems to be a mostly chemical phenomenon.  According to LiveScience, we're "stuck with" the amount of fat cells in our bodies by the time we're 20 years old, and that number is largely due to our childhood exercise and diet routines.  But maybe there's hope; because there's a function in the body that generates new fat cells when one dies, if scientists can figure out a way to cease this turnover, we could actually "reduce fat-cell number in adults."   

 

sophie b.'s picture

 I think its really

 I think its really interesting that childhood eating and excerise patterns determine the amount of fat cells we have in our bodies for life. I was reading an article in scientific american about brain development which discussed how the brain overproduces grey matter before puberty, which strengthens some neuronal connections based on the activities we do (piano students may strengthen auditory parts of the brain). Are these two things related? They are both lifelong consequences of childhood activity, that seem to exist kind of outside the i-function... 

AndyMittelman's picture

Corollary discharge vs. sensory input

I am curious to learn more about the details of the nausea reaction we discussed in class this week. As we talked about on Tuesday, when you’re driving the car, the nervous system is producing corollary discharge signals that set up the expectations. Furthermore, the less disagreement between the signals, the less likely you are to get sick. This seems logical to me; our body wants an agreement between the internal signals of our nervous system (the corollary discharge) and the external sensory inputs. When they do not align, it is very interesting that the body reacts by inducing a feeling of discomfort. If it’s really bad, we even expel the contents of our stomach, perhaps eliminating a toxin we may have ingested. What a brilliant evolutionary acquisition. But we also talked about how it is a failed adaptive process. I wonder if there is any way to alter how the nervous system constantly adjusts its expectation. If the adjustment is successful, we don’t get sick (and vice versa). Well how does the nervous system adjust its expectations? Do all adjustments occur with the same frequency and rate? When someone gets their “sea legs,” does that mean that they have gotten very adept at making these adjustments or rather is it that they don’t adjust at all and have started to suppress the mechanism that checks expectations against sensory input?

So if this whole thing is going on constantly, why is it that we evolved to do this process largely without involvement of the i-function? In other words, why is it that the i-function plays such a removed role in this complicated and constant event? I suppose this is just one of many events that occur constantly without our conscious consent. But can we override this? As in, if we tried to take a deliberate stance against getting seasick (and tried to consciously accept the disagreement between corollary discharge signals and sensory input), could we successfully suppress the impending seasickness? I don’t think so…at least I’ve never seen anyone succeed at this route.

Also, I’m interested to learn more about the setpoints that our nervous system creates. I am writing about firewalking for my web paper, and it appears that setpoints are the key “trick” to walking on fire.
 

aeraeber's picture

Do You Remember?

I think we’re well on our way to linking neurons and behavior, but as many times as we have mentioned input, we haven’t defined that clearly what input actually is, and how it influences behavior or conversely, how behavior influences it. Of course some behavior is entirely related to internal influences and events, but behavior wouldn’t be nearly as interesting or as complicated in general if it wasn’t influenced by the outside world. On a somewhat unrelated note, I’ve been wondering how behavior is related to memory in the sense of neurons and boxes and connections, since I’m reading In Search of Memory for my book commentary.  Is memory, declarative memory that is a separate box or is it part of many other boxes?  How does a memory get activated in order to influence a behavior? For example, when you see someone you’ve met before, how does the memory of their name become activated? For that matter, how do neuronal signals end up as speak?

In class on Thursday, we talked about the fact that both the spinal cord and the motor cortex control movement and that a motor cortex was not necessary for movement, but a connection between the motor cortex and the muscles was necessary for conscious movement.  This left me wondering if one system always overpowers the other and if so, in what situations? You can’t stop yourself from kicking at the doctor when he hits your knee, even though you know that’s what is going to happen, but are there other situations where you can consciously override a reflex? Are the two systems connected, maybe by corollary discharge?

 

Jeanette Bates's picture

Bird Song

            I have a few questions about the process of learning species-specific communication (i.e. language in humans, songs in birds). We agreed that a young member of the species can tune out other sounds, only paying attention to the sounds of its species. That would enable it to successfully learn the language or the song or whatever it may be. However, at least in birds, this doesn't always happen: (http://www.allaboutbirds.org/netcommunity/faq). Birds occasionally learn the songs of different species, or they somehow manage to create a new song by incorporating pieces of their species’ song and another’s. Obviously, not every bird gets confused and learns a different species’ song, but every bird is exposed to other bird songs everyday. So, what's wrong with these birds? Why do some birds get confused? Is there something wrong with the way they are interpreting information? And if birds are able to get confused about which song that they are supposed to sing, is it possible for humans to get confused about which animal they are supposed to mimic?  

kdilliplan's picture

More About Birdsong

 I’ve been thinking about our discussion of birds and how they learn their songs.  In class, we identified two components of the learning process: first, the bird hears the adult song of its species, then the bird goes through a plastic song stage where it “practices” the song until it crystallizes.  We decided not to try and get into the details of the role social interactions play in learning birdsong, but I have been thinking about a few studies I’ve read on the subject and I’m interested in how their observations fit our model of behavior.

 More details about the methodology of these experiments can be found here:

http://faculty.washington.edu/beecher/B&B-CDPS2004.pdf

To summarize, researchers looked used several methods to try and teach young birds their species-specific song.  One way was by letting the young birds hear the song directly from an adult bird in the same room.  Another was to isolate the young birds from any other birds and to play a recording of the song on speakers.  Another was to involve a “virtual tutor,” a machine that would only play the recording of the song if the young birds interacted with it in some way. They found that birds that learn their song directly from the adult will usually crystallize the characteristic adult song, while birds that learned from the recording often crystallized a non-characteristic song or remained in their plastic song stage for a much longer time.  The birds learning by virtual tutor, however, were more likely to crystallize the characteristic song than birds learning from a tape, but less likely than birds learning from adults.  This suggests that interaction between individuals is highly important to the learning process, but doesn’t directly fit our auditory template & trial and error model from class.  I suppose it would fit our model if we expanded the template idea so that the template is not only an auditory one, but also includes social cues as well.  This, however, doesn’t really account for the intermediate song learning showed by birds taught by virtual tutor. This leads me to wonder if feedback loops like this are all-or-nothing deals or if there is some sort of intermediate response and if so, what other examples are there? 

Jeanette Bates's picture

 I just wanted to say that I

 I just wanted to say that I agree with you. I feel like the crystallization of bird songs is a bit more complicated than the template & trail and error explanation. I also know that there are a few cases of birds learning a different species song rather than their own. I wonder how these things can be successfully explained. 

mcchen's picture

I-function vs. nervous system

 This week, we talked about how the brain is constructed like loopy science.  The nervous system has expectations and output from the nervous system is to promote new observations in order to refine expectations for later uses.  So without the I-function, the nervous system seems to rely on trial and error and "instincts".  Therefore, the I-function is our perception of what is happening in our bodies and it is what we use to make decisions.  It seems as though the I-function is present to excite and inhibit the instinctual functions of the nervous system.  Does this mean we really can't "control" most of the functions in our body? Since the I-function only gets a glimpse at what the nervous system is up to, we really don't have enough information to try and control what the body can and cannot do.  So then is it the I-function that can process external/environmental factors in order to make conscious decisions about how to react in certain situations? I guess I'm just having trouble distinguishing the role of the I-function from the rest of the nervous system.

mcurrie's picture

Ramblings

 When talking about the weight set point I thought about my dad who stayed the same weight from 18 until a few years ago and since then has gained some weight. But it seemed that he gained weight more because he was not moving around as much as he did while with the forest service. I see that the nervous system has something to do with weight but also the environment or activity of a person. So I am glad that we are now including the external input since it does not always seem that your behavior is only due to the nervous system. With paralysis after a stroke, although the I-function is not able to create an action due to the lack of connection although it seems since a person can still move their arm when a ball is thrown at them that the central pattern generator is still active and can be activated in order to protect the body. As if even though you’re not aware of the paralyzed part of your body it is still aware of your surroundings and keeps its function in keeping the body aware of dangers or other stimuli. What about a person in a coma, they still have their CPG's intact, but I don't think they respond to a ball being thrown at them. Are their CPG's damaged or latent due to the nervous system shutting down portions in order to extend energy to places in the body that need it? Do they still have an I-function? I guess I would say that they still have the nerves that form the I-function but that the function is dormant. I guess I'm just thinking about all the connections and keep wondering about what occurs when one of the connections, CPG's, I-function, corollary discharge is not functioning properly. With paralysis the I-function has no effect but the CPG's are still able to respond, while in a coma the I-function doesn't seem to be working or CPG's but maybe corollary discharge is still telling neurons what's going on in the body, keeping it aware of the outside although I'm not completely sure.

gloudon's picture

strokes...

 Today we talked about the consequences of strokes, and how they prevent people from using their I-funciton to control limbs on the opposite side that the occurred.  Unfortunately, I don't recall the term for the stiffening of the muscles after a stroke, but I do have a question about it.  So, stroke victims will react (with the limb they can't move) to a beach ball thrown at them, like a reflex. Therefore, they don't have control of these limbs because something happened between with the connection between their I-function and their motor neurons.  While I was searching for the name of the condition that stiffens the muscles in stroke victims, I am across the term hypertonia, which seemed to be the same thing.  However, hypertonia affects both stroke victims and victims of cerebral palsy.  Is there a connection between strokes and cerebral palsy?  

molivares's picture

Restless Leg Syndrome and Corollary Discharge

In our talk on Tuesday about corollary discharge and phantom limb syndrome, I’ve come to wonder if corollary discharge is related to restless leg syndrome.  Restless leg syndrome is a neurological disorder characterized by unpleasant sensations in the legs and an uncontrollable urge to move when at rest in an effort to relieve these feelings. The sensations are often described by people as burning, creeping, tugging, or like insects crawling inside the legs.  There have been no recent findings on what specifically causes restless leg syndrome, but it seems to me that it relates similarly to the role of corollary discharge in phantom limb syndrome. Since the cause of restless leg syndrome is unknown, there is has not been a cure for it. However, if restless leg syndrome does function similarly to phantom limb syndrome in terms of corollary discharge, perhaps the interventions used to treat phantom limb syndrome would be useful in treating restless leg syndrome as well?

randomness