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Caitlin Jeschke's picture


The last two posts (by Emily and Sophie) have touched on some of the ideas that I have been considering since Thursday’s lecture.  I too find the idea of internal v. external “inputs” to be very interesting.  The idea that the nervous system was capable of internally generating input was the aspect of our model that I found to be the most intriguing. 

            I wondered whether or not a thought or memory could be considered a type of internal input, because thoughts definitely affect the way a person reacts in any given situation.  A number of thoughts triggered by an external input, for example, could combine with that input and with each other to produce an unexpected output.

            When we talk about how different people react to the same input in different ways, we are necessarily basing this observation on external reactions that are visible.  As others have already mentioned, it is impossible to know an individual’s thought process.  So, different thoughts and memories could explain differences in what is conventionally referred to as “conscious” behavior.   But what about “unconscious” behavior?

            The excerpt that Sophie posted about how some processes are viewed as “physical” whereas others are viewed as “mental” led me to the observation that we do not often consider variation in behavior that is considered “physical.”  I am referring to bodily functions that do not seem to be subject to influence by memory-for example, food digestion or breathing.  These processes are all controlled by the brain, but involve inputs and outputs that are not as readily observable.  I think that it is extremely unlikely that all humans use the exact same neurons and the exact same pathways to maintain these functions.  However, because we do not “consciously” tell ourselves to expand and contract our chest cavity, or to secrete stomach acid, we often assume that these behaviors are identical in all people.  I think that slight differences in these behaviors probably exist, and that the “brain as a machine” model would most easily account for such differences; small variations in neuron connections (or in the construction of the “machine”) could lead to slightly varied outputs.

            So, although I feel that there can be no outputs independent of the brain, there definitely seem to be some inputs that are much more likely to generate thought (and therefore “awareness”) than others. The “conscious”/”unconscious” dichotomy persists.  However, I think the fact that our beliefs and past experiences can affect even some of our actions is very cool.  Some people have expressed discomfort over the idea that there may be no free will.  I say, even if memories and thoughts are just different types of internally-generated input, imagine what our lives would be like if we were not able to generate this input: if every action were as automatic as inhaling. 

            I think that both structural differences (i.e. unique neuron pathways) and internal input in the form of thoughts are responsible for behavioral differences, and that the brain somehow incorporates both of these features. 


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