Neurobiology and Behavior, Week 7

Do reafferent loops prove a part of Dickinson's claim that nearly everything is a contruct of the brain?  That our behavior is a construct of the brain? It certainly proves that brain= behavior in the sense that the brain uses its outputs as inputs and recycles signals in order to generate behavior. Reafferent loops, as well as a large percentage of interneurons in the brain, almost make me think that the brain doesn't need to rely much on environment for inputs (except maybe for the very first input from the environment that can spark an action potential). So is our interpretation of the world more dependent on our behavior and actons than the actual environment itself? 

I think reafferent loop is a mechanism that has been evolved in such a way to fisrt, minimize the energy/time of finding inputs from environment, and second, reinforce our brain of the pattern of our behavior (making even closer connection between brain and behavior). 

The loop draws a parallel to the following analogy: in mathematics, the shortest line that can be drawn from the two points, A and B, is a straight line between them.  This simple analogy exemplifies the first point which is the loop minimizes the energy/time of finding inputs from environment. 

The second point can be further expanded.  Reafferent loop forms reinforces one's identity and pattern through recycling the information originated from oneself within one's neural system.  For example, a person can observe one's health over long periods of time and figure out which food they need to eat and which they should avoid.  They tend to study their life-rhythms throughout their life.  This self-feedback or control is i think the result of evolution, indicative of more efficient and better neural pattern with minimum energy for maximum adaptation.

     The reafferent loop is a pretty amazing component of the human nervous system.  To be able to sense one’s own outputs and have such perception generate newly modified and ‘improved’ inputs is a very necessary and often overlooked aspect of our everyday lives. 

     Our discussion in class about a person reaching for something in the dark was very useful in elucidating the role of the reafferent loop for me.  By reaching for something that we can’t see and not finding or touching it, we talked about how the reafferent loop may play a role in being able to signal back to our nervous system, thereby generating an input which says that the desired item is not in the place that we have already checked.  Thus, this function facilitates additional, future searches for the same object in that it can effectively prevent us from checking the same area twice and allows us to eliminate places in which we have already directed outputs to explore.

      From this example, I began to wonder if it was at all possible that this reafferent loop was malfunctioning or compromised in people who have been diagnosed with severe amnesia or short term memory loss.  In cases where people do not remember whether or not they locked their door, turned off a light, remembered a person’s name, etc. (even after multiple attempts or interactions), is this loop simply not producing inputs which can be successfully redirected to their nervous system (in order to be used to influence that person’s related future nervous system outputs)?  Or is the problem that that person cannot retain the inputs that have been generated by this loop’s ability to sense nervous system outputs?

One question that was posed in class on Thursday that I continue to wonder about is whether emotions are outputs. If I feel sad, is that an output of or input to my nervous system, or both? How is the reafferent loop related to emotions?

On a completely different note, I am curious as to whether the idea of a "motor symphony" be extended a bit...In class, we talked about how a motor symphony allows us to perform everyday actions like picking up a coffee mug or opening a door handle. Are motor symphonies also related to thoughts/patterns of thinking? Does thinking have a "motor" component? Do people tend to think/process and analyze information in specific ways based on stored motor scores? Is education in any way responsible for helping us form "scores"?

In reading the most recent blog posts, I think that Brie raises a very valid point. Being a psych major myself, I have before thought about the possiblity that we are born with far greater capabilities than we actually use in our daily lives, and thus throughout the span of our entire lives. Knowing that human development is one of the longest developmental periods among animals, we can recognize that human beings are extremely vulnerable to external factors from birth. Doesn't this in fact acknoweldege that human beings are one of the most adaptable beings that have the ability to recognize a barrage of stimuli if given the chance? Knowing that infants are capable of mimicing & in time, learning, all of the different languages of the world, I believe that we are susceptible to & thus capable of utlizing many different stimuli.

For example, I firmly believe that if an infant was born in a cave and lived in darkness a considerable amount of his/her life that this individual would have far better night vision (& maybe vision for that matter), in comparison to an ordinary human being. Is this really that far-reaching? There are stories of children being born blind that have a much better sensation for when an individual enters a room or can decipher emotion just from speaking without any image of facial expression. Overall, one could state that they can "sense" the presence & behavior of human life better than an individual with sight. 

In conclusion, I do believe that human beings are capable of having nervous systems that are far more "in-touch" with a vast variety of stimuli, however, without being exposed to this stimuli, our capability of mastering the inputs and outputs from our external environment is lost. Furthermore, I think we should take this topic one step further and ask ourselves: what do we believe the human mind & body is incapable of, if given exposure & time to learn?     

As we discussed inhibitions and intuition in class I began to think about something called phantom limb sensation and how it could be applied to what were learning. The studydiscussed in this article from Scientific American used physical therapy to help reduce the pain in the lost limb. The article determined that, "...people with pathological pain have distorted maps of the body, or a generalized disinhibition of parts of the brain (reduction of the normal inhibitory control that keeps brain activations in check)."

What makes this find really interesting is that the researchers found that  visualizing the body/ the amputated limb alone can help drastically reduce the phantom limb sensation. "Simply thinking about body parts activates their virtual counterpart—one can’t feel one’s body without using neurons that represent it. Honing in on a particular body part requires inhibitory processes, the loss of which might underpin the extravagant activation patterns that were observed in the pre-training scans."
Phantom limb sensation highlights the importanceof inhibition and intuition in our nervous system.

http://www.sciam.com/article.cfm?id=phantom-limb-cure-retrain-brain

While I understand that neurobiology and psychology at two separate entities, I keep coming back to psychology in reference to several topics we've discussed this week.  Namely, we discussed if, at one point, we as humans possessed "all stimuli."  While it was ruled out in class if we did, at one point, possess "all stimuli," I still find an argument in favor of the fact that we may have.  In terms of language recognition as an infant, psychologists believe that we can understand/parse/hear every phoneme in every language of the world.  Over time, at about six months, we have heard our own native language so much that we begin to lose the ability to separate certain tones that once sounded different to us.  For example, Japanese children forget that there was once a difference between the "r" and "l" sound because there is no audible difference in spoken Japanese.  However, at one point, researchers proved that they could tell a difference between these two phonemes.

So still I wonder, could we have had, at one point, the ability to perceive all stimuli in the world?  However, having been raised as a human and in the social constructs of humanity, we lost several aspects of 'sensing' that didn't seem particularly useful to us?  It seems probable, if looked at with the above conditions in mind.