Neurobiology and Behavior, Week 2

I have always been intrigued by the notion of thought.  The idea that these pieces of

intellect or vivid recollections/memories can be drawn up without the need for an outside

stimulus is something that I’ve routinely wrestled with.  Typically, as we discussed in

class, we contend that in order for our nervous system to generate an output, it has to

receive an impetus or stimulus from the outside world.  However, as we can all attest to,

many times we find ourselves thinking, whether it be the product of careless daydreaming

or deep analysis of a certain quandary, about things that are not elicited by the world

around us or that are not capable of being physically experienced by our sense detectors

due to their absence from our immediate surroundings.

I have always been intrigued by the notion of thought.  The idea that these pieces of intellect or vivid recollections/memories can be drawn up without the need for an outside stimulus is something that I’ve routinely wrestled with.  Typically, as we discussed in class, we contend that in order for our nervous system to generate an output, it has to receive an impetus or stimulus from the outside world.  However, as we can all attest to, many times we find ourselves thinking, whether it be the product of careless daydreaming or deep analysis of a certain quandary, about things that are not elicited by the world around us or that are not capable of being physically experienced by our sense detectors due to their absence from our immediate surroundings.

For this reason, I believe that there must be a space within the brain that is designated for the storage of thoughts.  This would explain the idea that a person can think about something even without experiencing a particular input at any given time.  However, I also contend that many times what we think about is in fact dictated or subconsciously triggered by the outside world.  In these circumstances, we may be reminded of something we once experienced and this may in fact cause the stimulus to reopen thought processes associated with this idea or experience that we have previously stored up within our memory banks.  In this regard, the brain is essentially a search engine and a very efficient categorical organizer of the thoughts and encounters that we have accumulated over the course of our existence, capable of recalling and grouping certain outside data within storage banks within similar associated idea groupings.

I think the boxes within boxes model comes closest to what I've learned so far to modeling behavior. The stimulus response model explains many basic behaviors but does not allow for any wiggle room. As the Harvard Law of Animal Behavior states, behavior is not so easily predicted. I think the boxes within boxes and multiple inputs/outputs will allow us to model more of the diversity in animal behavior, as aybala50 also stated. 

If we believe that brain=behavior then we should theoretically be able to model all animal behavior. However, I'm not sure that scientists will ever be able to do this, which leads me to think that there may be some other better model or maybe, just that the human brain isn't smart enough to fully understand the human brain.

I appreciated the way the nervous system and the compartments of the brain were simplified. The idea that there are boxes inside of boxes allows for an understanding of what's going on inside the head without getting too involved and leaving room for intriguing questions.

What really interested me was the concept that genes and culture may effect the organization of the nervous system. That made me think whether the arrangement of my compartments were different from the person next to me. Also, it explains how two people with the same input may have a different output. This concept explains why certain things may be offensive in one culture but acceptable in another. But what also seems worth thinking about is, what is it that changes in the brain?? chemicals?? And is it ever too late to change one's "setup" persay?

I am very intrigued by the boxes model set forth earlier in the week, however, my biggest questions have more to do with the overall structure and design of the model.  In particular, my feeling is the following:

1. Is there any sort of valuation structure or built-in quality set in the model?  In other words, can we say whether any 'route' or any circuit is any more valuable, in the 'eyes' of the system, than any other?  My inclination, from my current understanding is to say, no, although I would be happy to hear otherwise.

2.  My reservation to saying 'no' to the above question is that I think the only thing foundational of this very relative and transient model is the input-->output poles, right?  Like a mathematical function, the model still has, for every stimulus, an output.  However, as Dr. Grobstein showed with the leech, sometimes you get spontaneous outputs, for no apparent input.  This suggests to me that in fact in this model of the nervous system, there is NO foundational properties, there are no real built-in valuation systems of saying any aspects of the model are more important for its functioning than any other components.  Maybe input is as equally valid as output.  If that's the case, why can't we just switch the model on its head and make outputs inputs and inputs outputs, and see if the model holds 'true' then?  Maybe the leech can in fact take several stimuli without emitting an output as well?  If one is true, why not the other? 

At the conclusion of Thursday’s class, it was apparent that the nervous system could function without conventional stimuli. Rather, the nervous system seemed fully capable of generating inputs and outputs, even in the absence of an input. This idea seemed unsettling but at the same time intuitively correct. During the course of our discussion, the notion of sensory deprivation was raised to further evince the aforementioned input/output model of the nervous system.

This made me think about how modern science, with this new definition of the nervous system, is working to understand and treat sensory deprivation. In doing a little research, I found numerous studies of the effects of sensory deprivation on cognitive function. Rather than focus on the more academic studies, and also excluding those of the Guantanamo Bay theme, I found an interesting article from the American Psychological Association describing “Mental preparation for Mars.” (http://www.apa.org/monitor/julaug04/mental.html)

The article outlines the current research of several prominent psychologists working to “lesson the mental stains astronauts might face 100 million miles away from earth.” Although one might be inclined to think that the greatest challenge facing Martian bound astronauts would be hurtling through space, dodging asteroids and space radiation, landing on a desolate planet (where we could finds aliens?) and then packing up only to repeat the process.  But as the article suggests, the dangers of delving farther into space also include a “grinding monotony.”

Being confined in a small space vehicle for approximately three years (NASA projects it will take 500 days to reach Mars, not counting the return trip) combined with the daily stress of manned spaceflight, incurs a massive strain on the human brain. Previous studies have found that being in an enclosed space “with a small group of people for long periods of time can result in cognitive decline, depression and interpersonal conflicts.” There problems can lead to disaster, since space flight is by no means an easy job.

So, NASA’s National Space and Biomedical Research Institute (NSBRI) is currently developing several ways to help astronauts’ coup with the long flight to Mars. These include a handheld cognitive ability test, and even a handheld computer that can stand in for a therapist.

These programs might also aid patients in a clinical setting, and aid in the treatment of depression. So, while NASA might have its heart set on Mars, these studies have applications beyond the field of interstellar travel.     

I'd like to begin with some thoughts I have in response to our conversation on Tuesday regarding the "linear model." As a child, I was taught something in-between the linear and loopy model- I was told to have a hypothesis or educated guess- is that very different than a summary of observations? Perhaps we're arguing more over language than the meanings of science. I was also taught to have a specific methodology/procedure, but that did not mean that I could not improvise or change my original goal. The purpose of my childhood science was to have fun, think, and discover something- all of which I find perfectly appropriate. In addition, I did not ever have the sense that science only happened in some sort of sterile, artificial laboratory. I always believed that science could happen in the mud, the grocery store, my living room, etc. Am I unusual? Interestingly, science became more linear once I started college and my premed courses. In my chemistry courses here, for example, there was a clear right and wrong answer and often our experiments were not fun- they were simply to prove what we already believed to be true. If something in the results seemed to contradict "the known," we simply ignored it or explained it away with experiemental error. Thus, I'd like to pose the question of whether Bryn Mawr science courses, especially those somewhat grueling introductory labs, can become more loopy? What might be the consequences of making them loopy?

It does seem to me that often the purpose of having students do science is not to have them discover something, but to instill in them certain educational values such as  dilligance, attention to detail, patience, etc.. 

I'm also interested in the question of whether students can be assessed in a "loopy way"? I'm not sure what a loopy assessment looks like because it would require the instructor to have no expectations as to what the student should know. In addition, it seems "non-loopy" to even have an instructor assessing because it implies that there is one person who is a superior judge of intelligence/performance. Clearly, standardized tests, like the SATs, are linear tests, but what about IQ tests? Those also seem to be linear. Is there such a thing as a loopy test that allows individuals to be measured against one another? Is that a loopy concept? Can individuals' brains be compared? Are some individuals more "intelligent" than others or simply intelligent in different ways?

During the week, I was reading an article about culture-bound syndrome. Basically, this talks about "disorders" that are only seen in specifical cultures, like the western culture. Two disorders they brought up were ADHD and anorexia. Although our culture says we're very liberal, we're really not. People care about how others react or view them. This leads to a certain type of reactions - a specific course of behavior or outputs. for anorexics, our input is that we have to look a certain way. The output can be that the person seeing the commericial (a possible input) has no reaction (reaction a) or starts trying to diet (reaction b).

we are in a a world where there is a box within a box within a box and then some. Our culture can be considered the mother of boxes, with all major inputs bouncing into us from our culture, and our reactions are to react within that box.  sometimes our outputs stay within the box of the culture, and sometimes it bounces out. That way, our culture ends up effecting other culture boxes - which explains why nowadays there is a rise of anorexia in the eastern culture. That makes sense, doesn't it?

When I was a child, I once stepped on a small caterpillarand saw promptly started to cry. An older friend came over to comfort me butwhen he learned that I was distressed over killing the bug, he quicklyexplained that it was alright because caterpillars felt no pain-they had tinybrains. I think that in our culture, bigger is better, and this principle hascarried over to brain size. Many people believe that our unique intelligencecomes primarily from the size of our brains; because our brains are larger,they are able to hold more information. I think that this basic theory has somemerit- humans do have very large brains, but are they proportional to our bodysize, or are they actually abnormally large. The human brain, while largecompared with other animals of similar size, is not the largest animal brain.In fact, when Cuvier’s fraction (E/S E=brain weight, S=body weight) is used,humans and mice have roughly identical ratios. (Source: /bb/kinser/Int3.html)If size does not play a significant role, then what accounts for ourintelligence?

Some Possibilities:

-The presence of the neocortex- this is absent or reduced inless intelligent creatures, and it seems to show the greatest variety. From myunderstanding, the neocortex is in control of all higher order thinking, whichmay be a distinctly human process. I also think that the highly convolutednature of the neocortex allows for more efficient packing of brain matter.

-Do humans simply have more neurons that allow for moreconnections to be made throughout a lifetime, or are human neurons lessvulnerable to destruction?

-Does our intelligence come from the presence of the “mind?”Do other, less intelligent creatures possess a mind, or do they only have abrain?