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Week 7 - Neurobiology and Behavior

Paul Grobstein's picture

From central patterns generators and corollary discharge signals, "choice" and "purpose" to the I-function? Plenty to mull over. Have a good spring break. Leave some thoughts here about where we've been/need to go for when we meet after?

eshuster's picture

The neurobiology of US airways employees

I had previously written this in the airport in Aruba at one of the internet machines where I had spent too much time on this page and therefore the machine decided to delete my entire entry. As I rewrite it now I have lost the anger and frustration that initially fueled this post.

I initially wrote my response while stranded in the airport at Aruba. I was surrounded by angry, worried, stressed and frustrated individuals whose flights had been canceled due to the weather in Philadelphia. The cancellation of the flight was not what caused the anger it was the lack of additional flights. When people are being rebooked for a flight a week after their initial flight there is obviously going to be anger and frustration. How will some people afford another week of vacation? Not everyone has extra money to do so. This post is not about the anger I felt or the anger the others felt but about emotions. I can only imagine the neurons and action potentials of the hundreds of people in the airport. The frustrated individuals, the bored children, the people that are happy they don’t have to return to work for another week and the airline’s employees that are the messengers of the corporate offices and yet have to deal with so many problems that they have no control over.

In terms of US airways employees, I wonder what is going on in their minds when they tell people they have no way to get someone home for a week or even 10 days (in some cases this occurred). The airlines would not pay for the hotel or food expenses because they claim it was weather related and they did not have to do that. It just makes me think what are anger, frustration, stress, and worrying. If thinking doesn’t actually exist and we are just experiencing various action potentials running through our bodies then what is anger? What is frustration? What is stress? Why do we do it? How do we do it? What types of action potentials dictate stress or frustration? When a US airways employee tells someone they have to stay in Aruba with no place to sleep for another week, what are the action potentials running through their mind? How do they differ from the frustration and anger running through the mind of the airline’s customer?

It seems that our bodies have endured so much “stress” that we have grown accustomed to it? But what is stress? Why is it said that when we have a lot of stress our health worsens and we age faster? If stress is so bad for us why do we do it so often? And why do some people thrive on stress? Some students even need to feel the stress piling on top of them before they start doing their homework or writing their papers. WHY?

How does this make sense? How do stress, frustration, anger, and worrying differ from a neurobiological perspective in our bodies? Do our action potentials occur at different rates, frequencies, or in different locations throughout the nervous system?

What is stress and why can’t we stop feeding off of it?

x's picture

Enough with the Pursuit of Happiness

There's an article on CNN Health today that discusses a man who describes himself as an "expert" on happiness. He recently published a book Happiness: A History, and basically says that the more you look for and desire happiness, the less happy you actually are. What disturbs me about this analysis is that it makes absolutely no connection to biology! Isn't there some kind of connection between hormones, genetics, and the ability to be happy? Or at least not be miserable? Isn't that what anti-depressants are all about?

The author doesn't attempt to define happiness and says even he can't achieve it, but all this blathering seems to prove his point correct - the more you talk about happiness, the more elusive it becomes. It just doesn't seem like his analysis about happiness is a correct or at all "scientific" one. What exactly was the point of him writing this if not to illuminate the obvious? Why exclude science from a conversation in which science could be of use? Frustrating.

Molly Tamulevich's picture


This is just something that I thought of a minute ago while I was scanning the headlines on the BBC. There's a polar bear cub in Germany who was rejected by his mother. In many cases, these babies are killed because if they were to be raised by a human caretaker, the eventual separation would cause them to become extremely depressed. An animal rights group wants to kill the bear, but the zoo says there's no reason to do so. This may not seem like it has anything to do with neurobio, but I wonder. Are we born with any values? Any taboos? There are certain cultural taboos that exist almost universally, but really...I wonder if our centers for right and wrong lean a certain way at birth. If the brain is home to everything, it is also the house of morality and difficult choices.

kjusewiczh's picture

Day Dream Believer

Yesterday I was looking through the news aggregator section of the forum area and I stumbled upon a very interesting article entitled "Lotto Makes Sense, Even For Losers". The author of this article presents evidence about why playing the Lotto is the most popular form of gambling, even though it has the worst odds. It was stated that this is due to the fact that the lotto causes people to fantasize about what they could do with a huge amount of money. Not only do they fantasize, but they also feel that their fantasies could come true because of the numbers they choose and they physical piece of paper they are able to hold. The author also states that evidence has been found that when a person is fantasizing about winning, the same neurons are activated in the brain that are activated when the person actually does win. I wonder if this happens with other types of fantasies as well. If so, I believe that this would help explain why day dreaming is so appealing to people. Every one day dreams, every one fantasizes...could this be the reason why? Are we fantasizing because it makes us feel the same way as if the thing actually happened? I don't have an answer for those questions right now, but I think it is very interesting to think about.

jpena's picture

Purpose of pathways

Last week I posted about reward pathways and commented on the idea of autonomy. I think it is interesting to bring in the idea of purpose. The "purpose" of reward functions is to reinforce behaviors to ensure survival. Addiction changes the effect of reward pathways, however, by reinforcing behaviors that can be detrimental to physical or emotional health. A basic example is when eating triggers a reward pathway. Normal eating (not over-eating) is not considered to be an addictive behavior. Alcohol consumption, on the other hand, is considered by many to be addictive. The same chemical processes are occurring but one is considered to be an addiction and the other is not. The original "purpose" of reward pathways is lost in the case of addiction even though the processes are essentially the same.

This makes me wonder about the idea of "purpose" in terms of brain functions. "Purpose" seems to imply a designer who created the brain and pathways within it that are meant to perform certain functions. If this is the case then the design seems to be flawed becase the purpose of a reward pathway is not always fulfilled. Or maybe there is no designer and pathways should not be considered to have a purpose.

Holly Stewart's picture

Who or What is in Control Here? Oh, and the Role of Purpose...

Ah yes, now (in my opinion) we are starting to touch on the meat of neurobiology as it relates to other disciplines (such as philosophy). With the discovery/categorization of central pattern generators we have encountered some new problems. Where is consciousness is all this? Who or what or where are these central pattern generators controlled? How do they communicate? Are these patterns the same across all species? And the questions go on, and so many remain.

My current concern is with purpose and control of purpose in these central pattern generators. I can’t help but think back to Richard Dawkin’s The Selfish Gene when it comes to the “control” situation. How much is really I-function? And is I-function either directly or indirectly influenced by our genes? Take an example: let’s say that you are scared of heights. So your I-function experience of heights may be altered by your genes and then this I-function information again influences your central pattern generators which may have varied effects (produce sweat or nausea when being exposed to a height-ful situation, etc.). I don’t know that it is so easy to define the control of not only these central pattern generators but also the I-function’s influence on them.

The next piece is communication. Does the I-function communicate with central pattern generators in the same way that action potentials are propagated? Can the I-function not only receive and transfer information but also censor it? Could this be why you don’t remember trauma or a traumatic incident because you have been able to censor it out of memory? And how does the I-function communicate with central pattern generators? Are there neural signals alone or could there be endocrine and neuroendocrine and other ways that we don’t yet even understand? Certainly I think neural signals are conserved in the body as an extremely useful (and for that matter) used way of communication, but can the I-function even be more subtle?

All of this leads me to the idea of purpose with respect to control. Who or what is really in control here? Right now it seems like the I-function is batting cleanup for whatever doesn’t fit nicely into our already developed scheme. I’m not sure that I am so okay with all of this. It seems unlikely that the I-function has complete and ultimate control since actions seem to be able to enter and leave this I-function-related capability box. An action can become so instinctive that you don’t even realize you are doing it, but then you are in a car accident and you have to learn everything all over again. And I have to ask, where is the I-function located? Does it have a physical location or is it something within the different parts.

Control (in my mind) is directly linked with purpose. We think of purposeful actions and we like to assume that we have some control over it. But could we train our central pattern generators to assume this role of purpose for us. How trainable are we? (This has some daunting implications…) I’m not sure what role the I-function has in our purpose, both our executable purpose (day-to-day activities) and this idea of ultimate “purpose.” It seems to me we are at a point where we need to identify who is really in control here.

Meredith Sisson's picture

Choice in Learning?

Reading Holly's struggle with the concept of control, it brought me back (yes, again) to the class' struggle with choice. After all, the question of choice is really a control issue, isn't it?

It seems that much of our discussion has tended towards the conclusion that we don't really have the "free will" we imagined and that our nervous system truly does dictate the course of our behavior. However, as far as our supposed lack of control over this process, I can't help but question the role of learning. Does the brain have a need for novel input on some regular basis? Much like our bodies call for certain nutrients or our genes pull us towards certain compatible mates? Or is picking up a new book, going to class, or watching the Discovery Channel choices we make for ourselves? Learning (at least beyond that required for survival) seems to suggest a matter of choice. Fundamentally, our minds and bodies don't require it for survival... but then again, perhaps optimal survival would?

Either way, it seems to me that the implications of choice on the concept of learning creates another "catch 22" in the understanding of the brain and its workings. If, in fact, we do choose learning, we would be capable of making a choice to alter our own brain structures. And if we were capable of such alteration, then we would be capable of controlling changes in the brain's generation of outputs. Thus the control would be back in our own hands. However, if we do not have a choice in the matter of learning, if the structure of our brains really do take control of those actions, then the brain itself would be causing its own growth and altering its own outputs... and why exactly would it be so common for our brains to engage in such higher thinking? How would this fit into the grand scheme of choice? If we don't have the ability to make the decision to read a new book, why would our brains make it for us?

Shayna or Sheness Israel's picture

Addressing the Fatalism after Demystification from Class

Addressing Fatalism as a Result of Lessons Learned


It is interesting. Based on something Durkheim wrote in the context of discussing religion, I write this as shorthand for what he was saying: Science as a dominant, legitimate truth producing mechanism takes away the magic from imagination. For me, I attach imagination to science in the sense that I base some freaky ideas on established or un-established scientific “truth.” It is fun.


I am not disheartened that this class at times demystifies the things that we have grown to believe are mystically and spooky. The class can at times be a party-pooper. Yet, that is one perspective. For me, no one can take the mystic away from the things/phenomenon that science tries to explain—especially because there are so many unknowns about the known. And the knowns are pretty freaky themselves: i.e. a holographic universe.


Addressing Feeling What is not There: I’ll Think Myself into Satisfaction


Ehuster: in a post you wrote: “I have seen that we can experience phantom limbs that we think are there but it's because the nerves think that they are there. I was so confused in class this past week because my brain couldn't wrap around the fact that we can feel what is not there ... being wrong has never felt so right.”


I would phrase it a little differently than experiencing something that is “not there.” It maybe easier for us to grasp. I would phrase it as such: The brain can feel what it thinks or thinks it feels. Now, that is empowering. Let me think myself into enjoying a nice piece of dark chocolate: Mmmm, the satisfaction.


Addressing Losing the Idea of Unifying Force


Yes, before and also now, I had an idea of a unifying force that holds us together and constitutes us—individually & collectively. This course does not discount this for me. It even helps me get more specific in where I attribute this holding-together function.


For example, I still have not forgotten about the electromagnetic field thing that we learned in the beginning of the class. We came to the conclusion that uneven random motion creates order.


That order constitutes who we are: If there are numerous central generators that act randomly with respect to other central generators and that motion is uneven, then there will be some ordered created in the form of an electromagnetic force field or something else.


This can be true for society in some sense, for we begin to define ourselves by the morals that hold us together. To the foreign observer, an individuals action may seem random as compared to another in that persons same society. However, upon closer inspection, with a wise eye, the foreigner would realize that there is some method to this madness he is observing.


Addressing Getting “Answers”


The questions are just getting started for me. I have not let go to the questions to which I have brought to class (all my classes). I will keep holding them, like a folded letter, to light of viable conclusions until I get a satisfactory message. I have not received one as yet. So let the investigation continue…

katherine's picture

music and language

This week I read an article in the New York Times called Skilled Ear for Music May Help Language.  The article described a study performed to determine the impact that music training has on those learning Chinese.  The study asked 20 non Chinese speakers, half of which had no music background and half who had at least 6 years of musical training, to listen to three pronounciations of the Chinese word mi which has three different meanings.  The brain activity showed that those with music training responded better to the Chinese sounds and were able to process the difference in sounds better.  Some believe that this works in reverse too.  In other words, native speakers of tonal languages may learn instruments better for the same reasons.

I wrote my first web paper about the impact of music therapy on Autism, so this article was particularly interesting to me.  It seems like music can profoundly impact our brains in many different ways.  It is evidence like this that makes me wonder how the brain interprets and reacts to music differently from other sounds, words, or languages.  In a broader sense, it makes me curious about how we are able to impact and strengthen different areas of the brain.  If musically trained people are able to learn Chinese faster, what other activities strengthen certain areas of the brain?  Are there activities that can weaken parts of the brain? 

Lauren Poon's picture

"The Brain on the Stand"

I’ve noticed that the New York Times Magazine has featured several articles in neuroscience. In particular, I liked the March 11, 2007 issue called “The Trials of Neurolaw.” The article, “The Brain on the Stand” discussed the controversial and revolutionizing effect of admitting more neurological evidence into the court system.

Once government test called the Impulse Test includes the possibility of a mental defect but does not does specify the extent. Could any slight abnormalities or imbalances in the brain excuse the defendant from punishment? What about simple chemical imbalances? Does age, born defects or trauma qualify as improper functioning? How does the legal system define a normal or abnormal brain? Mental defect seems to absolve too many people of the responsibility for their actions.

An interesting point made about age referred to the immaturity of adolescent brain. Many neurobiologists don’t consider neurons in the prefrontal cortex to be fully developed until the early 20s. The prefrontal cortex deals in part deals with a person’s control over their impulses. Teenagers are notorious for their strong impulses and lack of control over them. They often have poor judgment, rash decisions, immaturity. Why then does the penal system punish juveniles 18 and under instead of 21 and under?

Brain scanning may facilitate the distribution of justice. PET scans can detect trauma or abnormality in emotion generating region or decision making regions. Physical problems are significant pieces of evidence for the defendant’s case. Furthermore, investigations and criminal identity can be more reliable. Areas of the brain specify in face recognition. A victim’s brain could be monitored when identifying a suspect. If the face recognition area is stimulated when looking at a particular suspect, then the victim’s brain identifies, whether conscious or subconscious, the suspect.

I really enjoyed reading this article and would like to better understand why humans submit to impulses. How does the brain formulate criminal actions? Why do minds become so warped that a criminal might be able to justify such an actions? I’m sure outside factors such as the environment or upbringing influence behavior, but I would like to focus on biological reasons. Which parts of the brain, besides the amygdale and frontal cortex, create impulses? What other detectable brain reactions might aid the legal system? This article has opened my mind to the many ways neurobiology can positively change the legal system.

“The Brain on the Strand.” by Jeffrey Rosen from the New York Times Magazine. March  11, 2007

Ian Morton's picture

why the i?

It is certainly amazing to consider how little control our “I-function” really has and therefore how little control that we feel we have.  The I-function is only one contributing factor to the whole of my being.  However, while I do share the concern that my actions may not be the products of my free will, I must also recognize that I could not have the functional autonomy that I do have, as limited as it may really be, without the heteronomous input from the rest of my body.  If all the inputs that I received had to be filtered through and processed by my I-function/consciousness I don’t imagine I would be able to efficiently and rapidly make conscious decisions.

Anyway, what I am interested in learning now is how and why this I-function developed.  We have learned that the cortex is implicated in consciousness, but from where did this arise?  What were the environmental pressures that lead to the development of consciousness?  The motor cortex is not necessary for movement, but allows for the fractioning, localization and coordination of movements.  This seems to be a reasonable solution to an environmental pressure for more advanced movements, but what sort of pressures could have been in place that resulted in the development of recognition of “self?”  The I-function is responsible for our incredibly complex social network, so could then the I-function be a development in response to a demand for more advanced social organization?  Further, an article I made mention of in a post a while back mentioned how the area of the cortex associated with self-consciousness shuts off in times of increased stress – for example when running from a predator, in which case instinct serves as a better tool for survival than stopping to ruminate over one’s relation to a lion that’s about to eat him.  So if instinct provides such an advantage in these situations, what situations favor self-consciousness? 

alexa09's picture

I think everyone would say

I think everyone would say that the I-function is necessary. Although instinct serves most people well in situations such as running from a predator, most people do not spend a majority of their time running away from a predator. That is the change that I see; most humans are no longer required to act and think to just barely survive. Technically, I do not have to be in school to survive; I could be working to make money for food and shelter. The advances in social organization have taught me that if I go to school then I will have a higher chance of being able to provide food, shelter, etc. in the future. Perhaps all we care about is surviving, but it is not surviving the wild jungle of strange animals but survival of other people. Since we have rules on social behavior (i.e. murder, revenge, etc) our definition of survival is not the same as our caveman definition of survival.

LS's picture

Honestly Officer..I swear I was sleeping!

I have recently become intrigued with the strange side effects occurring with sleeping pills and read an article in the New York Times (F.D.A. Warns of Sleeping Pills’ Strange Effects) that covered this issue.  The two most famous drugs implicated in this article were Ambien and Lunesta.  Apparently individuals who have taken these sleeping pills are sleep driving and sleep eating.  These individuals claim that they go to sleep and then find them selves waking up with candy bar wrapper in their bed or pulled over on the side of the road.  I am curious about how this relates to central pattern generators.  I think we can assume that driving and eating are controlled by central pattern generators.  After all if when you are eating or driving you stop to consciously pay attention to what you are doing you will mess your self up.  The person is unconscious when these behaviors occur and usually do know remember or know what is going on.  What do these drugs do?  Do they shut down some inhibitory part of our nervous system that control behavior while we sleep?  Is the motor neocortex implicated in any of this?  Perhaps it is inhibited by the drug, would some one be able to do the single finger movement trick while in this state?  I guess I am just curious how the drug seems to simply turn on these central pattern generators and cause out puts.  Obviously the I-function in not involved in these cases, I guess that this should come as no surprise as the I-function does not need to be involved for the central pattern generators to work.  I find these behaviors so bizarre and frightening that I am wondering what the medication does to the nervous system to stop the inhibition of or to cause these behaviors.

Pleiades's picture

Nocturnal Eating Syndrome

Sleep eating (nocturnal eating syndrome-NES) goes a little further than that. I’ve read that people on ambient (and even not on any medicine) are sleep GOARGING. They wake up and go to the fridge and all the food is gone. They eat more than they ever could/would when they are awake. Although this condition affects both men and women, it is more common in females. It also occurs in daytime anorexics. They starve themselves during the day and unconsciously binge at night. This I think brings up the interesting point of self-control and unconscious behavior. In the case of the anorexic, she is using her I-Function to change her body’s natural behavior (not eating when she’s hungry etc). But then her I-Function is taken over and she unconsciously eats all the calories she should have during the day (unfortunately all at once). So instead of the I-function taking over the body (as in with psudocyesis and shingles), the body took over the I-function. Its also interesting that this must happen during sleep. Perhaps this is when the I-function is not active (which seems likely) and the unconscious can take over.

AriannahM's picture

Obestiry and Set Points

The idea of obesity and set points is particularly interesting to me. I took Biopsych at Haverford last year, and we spent a considerable amount of time on this topic. The way I understand it is a little bit different (I think) than how it was explained in class. As you ingest more calories your body begins to increase your set point and store more and more. This process is relatively easy, as humans are designed to hold onto fat just in case there isn’t more food in the future. When someone tries to lose weight they are going against what our bodies are naturally designed for. The body wants to hold on to fat deposits especially when caloric intake is down. This is why it’s so much harder to lose weight than to gain weight. Back to gaining weight, it takes repeated “over-eating”. Eating a lot once in a while won’t cause you to gain weight but eating 200 extra calories a day for two weeks will being to change your set point. I think this concept is so interesting. On the topic of obesity, I don’t think it’s that our notion of thin has changed; people have gotten heavier. Due to processed foods and more available nutrition, increasing set point is becoming easier and easier. While I don’t argue that some people have a naturally higher set point than other people, I do not think some people are naturally unhealthily overweight. Obesity is a very challenging problem to tackle because unlike other health problems like high cholesterol or high blood pressure, there is no pill to “cure” it. It will be interesting to see how the problem is solved in the future.

JaymElaine's picture

I agree with everything that

I agree with everything that was said here. This topic also interested me.  I am even happier that we have found a more scientific reasoning for why people do not lose weight as easily as gaining it, instead of using the excuse that some people are just "big-boned" (something that just sounds absurd to me). Perhaps it really means the same thing, but the phrase itself just bothers me (lol).  

Jayme E. Hopkins, '08

biophile's picture

Beating a dead horse- let's talk about free will

I've been thinking about what was said in class about spastic paralysis and about involuntary movement in general... At the risk of sounding spectacularly obvious, it's a strange concept that we sometimes can't control our own bodies. Tic disorders and the like have always interested me because those suffering don't want to do the things they do. I often wondered why exactly they couldn't consciously override whatever impulse they were feeling... And where in the world did that impulse come from, anyway?

Of course, tic disorders are very different from spastic paralysis. The movements sufferers make are voluntarily made in order to relieve an irrational urge. But... What does that look like? I mean, in what way are involuntary movements and voluntary movements made to relieve an urge different in how they're carried out? How are the brain signals different? I can't imagine the mental anguish associated with disorders such as Tourette's. One would feel hopeless, as if one's mind were against oneself. It sounds scary... Although to some degree we all feel that way at times. I'm sure we've all had problems with self-discipline before and we can't control certain things (such as the moment when we're able to fall asleep).

I was reading something about alien hand syndrome as well... In this disorder, one of the sufferer's limbs acts without conscious intent on the part of the individual. It's thought that this arises from damage in the corpus callosum. A simple way to break it down is to say that the will reported by the left hemisphere does not correspond with the actions performed by the right hemisphere. Another odd thought, isn't it? Does each hemisphere have separate wills? What do we even mean by will anyway? Can there be many wills in an individual? Or can there only be one that results from unblocked communication among all parts of the brain?

Even in neurotypical people the answer is difficult to see. It reminds me of Libet's famous experiment in which he asked his subjects to make a movement randomly and, while watching a clock with a third hand, denote the instant at which they consciously decided to move. In general, he found that people felt the will to move half an instant after brain activity associated with the movement was recorded by his machines. It's not a perfect experiment, but the message hits close to home: do we consciously make decisions? Or do we just think that we do? Maybe our minds know more than we ourselves do... If that makes any sense at all.




leigh urbschat's picture

Laughing as social response?

I came across a fun article in march 13th NY Science Times entitled, "What's so funny? Well, maybe nothing" that has to do with our perceptions of choice that we had been discussing in class. It seems that now scientists are leaning toward the notion that laughter may be an automatic response to a situation rather than a conscious effort. Scientists have found that human laughter is linked to the rhythmic sounds made by primates when they tickle, chase and play with each other. Even rats have been found to emit ultrasonic chirping while tickled that cannot be heard by human ears. Prof Panksepp of Wash U, who was interviewed, stated that he believes laughter to be the result of ancient wiring within mammals brains which encourages young animals to play with each other. He went on to say that "Primal laughter evolved as a signaling device to highlight readiness for friendly interaction. Sophisticated social animals such as mammals need an emotionally positive mechanism to help create social brains and to weave organisms effectively into the social fabric." According to the tests cited in the article humans tend to laugh more when they are in a situation in which they do not have the upper hand and are trying to make allies. We want to be liked and included and for that reason we will laugh at even a bad joke that is told by a superior. I thought this article brought up another challenge to the way in which we think about actions that we thought were by choice. So next time you find yourself laughing out loud, take a moment to ask "was that really funny?"

dmckeever's picture

But CHOICE people, what about choice?

I’d like to return to the concept of “choice” that we were covering in Tuesday’s class. Isn’t anyone else disturbed by this idea that many of the actions we take that we thought were acts of free will and of choice may actually be behaviors, or responses to patterns of action potentials, automatic responses to a stimulus coded for by the pattern generators pre-existing in our bodies?! There must be some actions we take that are external to these needs and demands of our bodies and outside of the direction of our nervous systems. Right? I mean, I have always been taught that I make my own choices and direct my own life, but what if all along, our bodies are driving us in a certain direction, and when we resist that direction (somehow) and overcome these demands is when our body rejects us (we get sick?).

 I considered eating as an example: so, up until now I thought, I choose to eat breakfast and dinner daily, and  sometimes lunch; I choose what I eat and how much; technically, I could stuff myself until I puke. But, what if our bodies are saying “I’m hungry” and our  response is “I will eat now.” This is not far-fetched and makes a lot of sense, i.e. this is probably what we actually do. But, what if our bodies also say “I  need protein,” and that “choice” we made to  eat steak for dinner is actually a behavior response to the firing of some pattern generator, signaling the body’s need for protein? Well then, it’s no longer a choice right? Like the example in class: the pleurobranchea—the act of retracting its nose is not a choice if under the condition of chewing, the only response is to not retract the nose; this is a result of pattern generators inhibiting the retraction; but  by definition, there are no longer 2 or more possibilities, right? There is only this one response of the pattern generators put in place to act when certain conditions (i.e. chewing) are occurring.

Well, maybe a simple, everyday act like eating is the same. I am reading a book about a woman who suffered from eating disorders much of her life (Wasted: A Memoir of Anorexia and Bulimia, by Marya Hornbacher) and she writes a section that seems somewhat appropriate to this specific question of eating: “I decided to eat once a week, in penance for the minimal eating I’d done at home. I ate on Sundays. Rice. I did this until I began bingeing and purging almost autonomously. This sounds very odd to people who haven’t been malnourished […] but scientifically speaking, your body will actually override your brain and make you eat.” She continues to describe uncontrolled fits of eating and then realizing what she had done, and throwing it up. She describes something almost like a blackout: she cannot remember how she got to a restaurant or ordering the food, but comes too half way through a plate. If in these extreme cases one’s body can take charge, is it so crazy to think that maybe it does it on a daily basis to keep these extreme cases from happening?

Back to one of my original thoughts, this woman (Marya), somehow rejected her bodies demands and went along her own path of not eating and  denying her body nourishment; and her body rejected her—she almost died. But then, starving herself was her free will, right? Because it is most obviously not what her body demanded. Or, was it a response to some other input, whether it be a society that promotes the model-like body type, or a mother that called her fat, that triggered something else in her brain (like a pattern generator) that caused her to starve herself—and as long as she perceived that input of “I’m fat; she thinks so, and he thinks so, and my own mother thinks so,” then this response is elicited. Now, I know this isn’t exactly evolutionarily beneficial, and so such a mechanism (this specific one) should not have survived natural selection, and this entire proposition is a bit outlandish, but if I can reason this, than I should be able to reason other, more plausible examples as well.

I haven’t made much progress on my original question, but I have had more time to think and so I am more terrified of the possibility that everything I do is dictated by some biological mechanism—even writing this post may not be a choice I am making; it may be voluntary because as far as I can tell, I want to be writing this right now, but may have been the only possible response to the discussion we had in class (the input), which triggered thoughts in my mind that resulted in this.

Aditya's picture

Advances bring questions: is ignorance bliss?

Prof. Grobstein mentioned a couple of examples in class of when the motor cortex was damaged and the resulting postures in different animals. A particular example used was a condition called Spastic Paralysis in humans where the arm was locked in a flexed position as a result of damage to the cortex. The person is paralyzed in the sense that he can not willingly move his arm, but the nervous system was still in control of the arm because it was sustaining it in a flexed upwards position, and also if you through a ball at the person the arm would block it as part of reflex programs.


Two conclusions were made from this:


1-     The body has evolved to adapt to gravity. When the cortex is damaged, the body positions itself to oppose gravity. This opposition to gravity is in the core programming and core hardwiring of our bodies. It’s like an essential central pattern generator and our bodies move otherwise by inhibiting this pattern. This incorporation of the scientific principles of gravity cannot be overlooked. In my viewpoint, it is clear supporting evidence of evolution because our bodies evolved systems and core central patterns to incorporate characteristics of the surrounding environment. In this way, this find is amazing.


2-     The ability for the I-function to interact with the nervous system and produce desired movements is inhibited when there is damage to the cortex. By default, it was concluded that the I-function is potentially located in the cortex. When we learned this it felt really good to give the I-function, what was an abstract concept since the beginning of class meetings, a potential physical definition. The ability for us to control our body lies in the cortex. Wow!


These astounding advances and conclusions naturally spawn other ethical issues. In the latest issue of The New York Times Magazine, Jeffrey Rosen wrote about how neuroscientific advances might amend the legal system. Some particular examples talked about studies by Adrian Raine who examined the brains of convicted murderers using PET scans and brains of people with antisocial personality disorder correlated with violence and found that the convicted murderers had reduced glucose metabolism in their prefrontal cortex and people with antisocial personality disorder had significantly less grey matter in their prefrontal cortex. This brings up the idea that the cortex which potentially allows for the I-function to function, if damaged or is not functioning properly, might influence or not inhibit our natural inherent actions, and things like spastic paralysis, or as Raine suggests, violence occur. A number of questions comes to mind.

Can we ever not hold people accountable for their actions if their cortex is not working properly? How much influence does the cortex hold over a person’s behavior? Is disinhibited behavior a result of cortex malfunction or is cortex malfunction a result of disinhibited behavior (outputs can influence inputs)?

Should we be further researching these findings, are we just giving criminals an excuse?

Paul Grobstein's picture


Speaking of, among other things, the NY Times, see The Brain on the Stand in yesterday's magazine.

lrifkin's picture

In Response...

I just read that very article in The New York Times Magazine a few days ago and wrote my post for next week on it. I also spoke with a family friend who is a jury selection consultant about her thoughts on the article--It is truly fascinating, and I plan to write my next webpaper on the topic!

lrifkin's picture

The Obesity Obsession

Although I unfortunately had to leave class a few minutes early, I was able to take part in our discussion of weight and set points. This intrigued me, especially when the concept of obesity was brought up. It was difficult for me to accept that certain individuals had an obese set point, or that their bodies actually wanted them to carry that weight.

After coming home I discussed the concept of a set point with my parents and family friends one night at dinner. Someone suggested that perhaps, in fact, there is no obesity epidemic at all. Rather, she said, society has changed its of definition of obesity. She noted that movie stars have gotten thinner, sizing on jeans has changed, and, in general, our culture’s perception of thinness has become increasingly smaller. That night I became more comfortable with the idea that the obesity epidemic may be, in part, media hype.

However, I was, and still am, puzzled by the idea that two individuals of the same height can have completely different weight set points. I read an article in the New York Times, titled Fat Factors (, which shed some light on this. The article explained that weight is maintained by the number of calories an individual ingests and the amount of calories an individual burns. It went on to suggest that some people’s metabolisms are designed to survive in harsher environments. These individuals can maintain a healthy weight while ingesting a fewer amount of calories and burning the same amount of calories as their peers. The article also suggested that certain viruses could potentially be responsible for making people fat. These viruses are found all over, and are unavoidable as people begin to acquire them at birth. Although studies are not yet conclusive, they show that not all individuals end up with the viruses that have been shown to cause obesity. Thus, could these viruses affect set point? Are all people born with the same set points, only to have them changed due to outside agents?

If these viruses are the culprits causing set point change, is there a possibility for them to be treated or prevented? Also, can traumatic events in an individual’s life change their set point? If so, is it possible for their set point to ever return to its original place? And, if this is the case, then if set points can constantly change, are they really set at all? It seems to me that weight is a highly fluid aspect of human development, and that in order to maintain it, it must constantly be watched.

Alex Hansen's picture

Obsesity and Anorexia?

The topic of obsesity is very interesting and how the body deals with food intake, how the body's metabolism works.  The mechanisms that change one's metabolism such as excercizing to increase metabolic rate appear to have an importance in examining how the body deals with calorie intake.  Do such activities account for this set point change at all?  How much excersize is specifically needed if it is such a cause of the set point change?  Can two people excersize for equal amounts of time, yet cause a different set point change for their individual bodies?  Does excersize play a role in the harsher environment explanation of why two different individuals can have different set points even if their height is the same?  Can excercize fight against these explained viruses that might act as the reason behind these set point changes?  What can an individual do to protect themself from these viruses, to fight against these viruses?  If excersize is infact a protective measure, are there others as well? 

How does sex play a role in these differences as well? How can there be so much difference between males and females in body type and metabolic rate?  Are these viruses affecting set points different for males versus females?

Also, what role does heredity play in obesisty and metabolic rate?  Body type appears to be hereditary, so how does this affect set point changes?  Does this work to support the fact that people are born with certain set points?

Also, what affect does anorexia have on these points?  It is known that after a certain point of basically starving oneself, the body's metabolism begins to shut down because the amount of calorie intake becomes so low.  Does this have any affect on the heredity of the set points if the parent is anorexic and has messed with his or her metabolism in such a way?  Also, does this perhaps by any chance weaken the immune system and possibly make the individual more susceptible to these viruses?  As the sizes of clothing have changed and the notion of what is thin continually increases to that of lower weights, and the size of models as well has become smaller, is it true that the number of individuals who are anorexic increases as well?  If so, and this truly affects these points and the metabolism, what will eventually happen to these points in years to come as anorexia increases?  Are more people becoming susceptible to these viruses, the children of these anorexic individuals?  Although anorexia is almost the opposit of obesity, both involve calorie intake that does not correspond to their weight and height, does not correspond to their needed calorie intake for that day.  What is eventually going to happen to these points as both obesity and anorexia seem to be increasing? 

marquisedemerteuil's picture

hey rifkin, there is

hey rifkin, there is interesting stuff about the obesity question and how it relates to society in evolution of stories week 4. i talk about what i think these statistics really mean.

Sarah Powers's picture

Need Development for Neuro

In the NYTimes' ScienceTimes section on 3/6/07, there was an interesting short that caught my eye because it involves the two bio classes I'm currently taking--this course and developmental biology.According to researchers at Cornell, in embryonic zebra fish, neurons the ventral side of the developing spinal cord fire when the fish is swimming slowly, while neurons on the dorsal side fire when swimming quickly.  When zebra fish swim slowly, only the tail muscles are active, but while swimming quickly, the entire body is involved.For the developmental biologist, these studies have shown that different proteins are released from the dorsal and ventral sides of the spinal cord, and create concentration gradients which help in the differentiation of nerve cells.  From this information, it sounds like the cord secretes morphogens.  Knowing how cells become specified is quite important to the developmental biologist.For the neurobiologist, these patterns in firing look like they could have something to with central pattern generation.  But in order to say for sure, you would need to see the order of the neural firing--whether they're all firing at the same time or in a pattern like in the crayfish example, and if certain neurons are removed, what sort of effect does that have.It would be interesting to know how early these sorts of movement patterns develop.  This could give us information on how quickly the motorneurons are able to function in a zebra fish embryo.  Also, what are the other properties of these proteins secreted by the spinal cord? Are they only made during development or do they have another purpose in the grand-sceme of the zebra fish lifecycle?  One last question. If you somehow made a mutant that wouldn't be able to create the spinal cord proteins, how would that effect the neural firing and movement of the embryo?The wiring in the nervous system from zebra fish to humans is completely dependent upon the development of the particular organism.  We can change the neural connections in our brains by listening to a lecture and learning the material, but we wouldn't have any wiring to change if development hadn't proceded as planned.  (That's not to say that development is the same between all humans, there is infinite room for variations, as we've already covered).  I guess my point is that as we move forward in the course, I would like to explore neural development on a behavioral level.

RachelBrady's picture

I came across the same

I came across the same article in Tuesdays ScienceTime’s, and what peaked my interest was the involvement of the unnamed proteins released during development and the role they play in the differentiation of nerve cells. In contemplating this I recalled (from intro bio) that certain hormones are able to stimulate neurons to increase the number of synapses the neurons receive. In this category were sex hormones, which have powerful effects on the development of the brain and behavior in human beings, and affect behavior throughout development. Changes in the sensitivity of neurons, due to these hormones are presumed to bring about changes in neural circuitry and sexual behavior. I would be interested in investigating this further; how hormones affect neural circuitry and what could result from isolating that effect

emilie's picture

Insufferable Clinginess, or Healthy Dependence?

When I read this article in the New York Times, it made so much sense to me and explained my relationship issues almost to a T. In the article, it says that in certain situations, being dependent on a person can be beneficial, especially in times of hardship. For example, a couple that is highly dependent on each other will be much more anxiety ridden over a dispute than a couple in which the two people are more self-sufficient. In the dependent couple, there will be more of an effort to reconcile for fear of abandonment. It has also been found that more dependent people tend to do better in class because they are more likely to seek help from the professor. It is suggested that these dependent or self-sufficient traits originate from attachment styles that are acquired during childhood. Children who are less secure cling to their mother more whereas securely attached children are more able to explore and be independent of their mother.

From reading this article, it made me think about our conversations about choice. It can be said, if simply relying on the Emily Dickinson model, that attachment style is due to certain connections or pathways that are formulated in the brain during crucial stages of development. Therefore, do we really have a choice in the way we act in relationships if we are already pre-wired to feel a certain way? Can a dependent person learn to be more self-sufficient? If we are not able to adjust to certain situations or relationships, then what is the point of marital therapy? If two personalities clash and if we know that we have been programmed to act and feel certain ways, should we not then seek out others that will compliment our personality traits rather than struggle to change in order to make a relationship work?

Cayla McNally's picture

Depression and the Heart

I’ve just read an interesting article about the effects of depression on those suffering from heart failure (“Depression Worsens Outcomes for Heart Failure Patients”), which states that patients who suffer from depression are over 50% more likely to die or be hospitalized for a heart condition than those who are not depressed. In all, those with depression suffer more negative effects on their hearts than those who do not have depression.

It is still unsure why those with depression have more heart problems, but this demonstrates how mental diseases have effects not just in the brain, but also in the way the body functions. If the mind is in a negative place, that is reflected in the body.

Darlene Forde's picture

Love and Health

Cayla's post reminds me of book written Dr. Andrew Weil. In the book Weil points out that he has observed a unique trend among people designated with life threatening illnesses such as cancer or other systemic diseases. Two experiences in the patient's life appear to "cure" disease—or at least put these conditions into remission: religious conversion and the act of falling in love. As a future physician, I find this concept fascinating. It gives rise to so many questions.

If religious conversion and the act of falling in love can reverse the course of different diseases, how is this accomplished? Is this accomplished by raising levels of hormones in the blood?

Let's consider the stages of falling in love (if only because it is easier to find information about the biological effects of love on the internet than religious conversion). According to one BBC article there are three stages of falling in love: lust, attraction and attachment. In the lust phase, testosterone and estrogen predominate. In the attraction phase, monamine neurotransmitters dopamine, norepinenephrine and serotonin are at their peak. Finally in the attachment phase, the hormones oxytocin and vasopressin play key roles. Is it a combination of some of these hormones that is responsible for disease remission?

In a previous post, I explored the role that hugging plays in increasing the levels of oxytocin—a hormone thought to be critical to bonding not only between mother and child, but also in couples.

If this is true, should we engage in matchmaking for those individuals with difficult to treat conditions? Surely this would be more cost effect than many current therapeutic strategies.

One psychologist from York England performed a study where strangers were introduced to one another, told to reveal intimate details of their life for 30 minutes, and then told to stare into each other's eyes for 4 minutes. Many of his couples felt deeply attracted after the 34 minute experiment; two of his subjects later got married to each other.

Cayla sums it up correctly when she says that “mental diseases have effects not just in the brain, but also in the way the body functions. If the mind is in a negative place, that is reflected in the body.” I would merely add that when the mind is a positive place, it also reflected in the body. The important thing here is develop new ways to maintain the mind/nervous system/etc in positive ways, so that it can heal itself.