Neurobiology and Behavior, Week 5

(Sorry for the late posting)

I'm very interested in our discussion about the differences between brains of males and of females and how this only apply to population but not individual. My thoughts about that is, it is an other good example of the gradients in biology. For many traits - especially those in human brains - the difference among individuals is gradual. If we imagine different phenotype of a gene as an axis, we may see an end as "completely male" and the other "completely female", but most people's traits will probably fall between the two, and there are no breaking points on the axis. What biology always amazes me is the great diversity caused by the combination of these gradual differences among individuals. What is more, these gradients are not limited among organisms of the same species, but also through the line of evolution. When we look at brains of different mammals, we can see that as well. These gradients create infinite possibities of the biological world.

After class I thought more about the idea that all brains are made of the same stuff with some well characterized connections but that this idea of plasticity within the brain allows for differences between people. So I read an article in Scientific American Mind about a new discovery of jumping DNA as a potential reason for neuronal plasticity and differences between people's brains which could create the individuality in personalities we seewww.scientificamerican.com/article.cfm. This would be molecular evidence against the idea that there is a separate soul/mind.

I find the idea of the "I function" fascinating and I am excited to learn more about this. The idea that the mind can assess itself or that you can view you outside of your brain is suggestive of a second brain(mind/soul).

We first talked about Dickenson’s and Descartes’ definitions of the brain and mind and how we see the world around us. We discussed which theory each of us favored, or found more comforting. Did you like the idea that our thoughts and behaviors can be broken down into billions of neurons or the idea that the mind (one’s sense of self and ability to make decisions) is a separate entity from the body?

This past week’s discussion got us talking about topographical organization and patterns of neurons and the I-function. The idea that every human brain is different (and these differences correspond to differences in behavior) is, to me, more comforting than anything discussed by Dickenson or Descartes. While no motor neurons are specific for any type of behavior, the way in which all the neurons in the brain receive, process, and transmit information creates interesting and diverse patterns of motor neuronal activity (behavior). This slightly more empirical explanation for the individuality of human behavior feels more right to me.  In addition, the introduction of the “I-function” as the “box” containing a restricted sense of how we perceive our actions and ourselves was very interesting. I would like to learn more about this I-function and its connections to other parts of the brain and the body. If the I-function is related to how we see ourselves and control our actions, is it connected to personality? Could differences in connections to (or in) the I-function be responsible for individuals seeing themselves and their interactions in a distorted manner (BDD, delusions, social phobias, etc.)? What causes the extreme discrepancies in the “thoughts” of different individuals? Is our sense of self solely located in this I-function (I find this hard to believe, though the thought is intriguing)?

 

One of the questions posed in class this week was what was the main difference between mammals and other vertebrates.  I was thinking about this in terms of the nature versus nurture argument and also in light of a recent article I read www.nytimes.com/2010/02/16/health/16brod.html concerning empathy.  I am wondering if the main difference has to do with the nuturing ability that mammals have that perhaps vertebrates do not have.  Perhaps mammals are a mixture of nature and nurture, while vertebrates are simply nature.  This makes sense to me when considering emotions such as empathy and how mammals have the ability to foster and encourage certain innate emotions.  Mammals, as a result of a larger brain and a greater capacity for thought, have the ability to construct complex emotions and feelings such as empathy and love and affection, that perhaps vertebrates are mentally ill-equipped to construct.  Just a thought...

I do appreciate our new box labeled the I-function.  Does this I-function = mind?  Or do we normally associate mind as being disembodied or separate from brain?  Is this I-function unique to mammals?  Is it unique to humans?  If the I function box is where the self is created, is the I-function box limited to mammals with self-awareness or are there I-function box variations? I am very interested in exploring this I-function box construction.

 I found the idea of an I-function to be extremely intriguing. When contrasting this with the boxes in the nervous system we explained that unlike these boxes, which in large numbers affect behavior, the I-function is not necessary for behavior. If we define it as the “me” box, something that is conceived and experienced by oneself and not the outside world, what then is its role in the nervous system? The example of Christopher Reeve’s accident and ensuing diagnosis was helpful in exploring this idea. Since his nervous system was interrupted in a particular location, he lost the ability to control his limbs on his own; however, he could still respond to stimuli to his nerves. This exemplifies the notion of the I-function if the I-function is understood to be a box that can influence an output by generating an input. The catch is that it is dependent upon other boxes for access to the input. To me this implies that it is intricately connected with the other boxes of the nervous system, thus indicating it is a part of the nervous system. But where is it located? In Christopher’s Reeve’s case, there is evidence that it could be located in the brain and was rendered inactive since his cables were not linked. However, I am still not sure if this is the location of the I-function.

On a somewhat related note, I would like to further explore the meaning of pain. At the end of our discussion we mentioned that one does not have to have previous experience of pain in order to feel it. If this is true, does that mean it is an innate feeling? And if so, how do we explain the varying experiences of pain held by different people? In the case of Christopher Reeve’s, he could not feel pain because his cables were not linked and he was located on the other side of the cables. With this in mind, I wonder if pain is a part of the I-function box. This is an area that I hope we continue to discuss in the coming classes.

The Christopher Reeves example used in class helped to distinguish (for me) those actions controlled by the brain, and reflexes controlled by the stimulation of nerves. It helped me understand that for a neuron to fire, causing a nerve to send signals to muscles, no pre-approval from the brain is needed; it is simply a reflex. This is much the same way someone can be in a vegetative state yet they continue to breathe and their heart continues to beat. However, why is it that if I want to move my toe, I can, without the need of any external, physical stimulus? This is where the I-function comes into play. In class, the I-function was vaguely defined as a 'box' within the brain that can send inputs to different parts of the body, thus controlling the output. (Example, I 'tell' myself that I want to move my toe and then I move my toe). However, in order for the I-function to work, it must be connected to the rest of the nervous system, I think these cables are found in or near the brain stem. I would not be able to move my toe, if I was not connected to the rest of my body, such as Christopher Reeves.

This all seems fairly easy to understand, but I still do not understand why we seem to equate the I-function with the "Self." From a biological perspective, are they necessarily the same thing? Dogs for example, are classified as not aware of the "Self," so do they not have an I-function? Could a dog not move it's paw because it wanted to do so? In class, I felt we were using the I-function and the Self as synonymous terms when they might not have to be. Perhaps a better example is young children, babies are also classified as not being self-aware, yet I am quite certain a 12 month old child will perform certain actions simply because he/she wants to. So, do we always have an I-function through which the "self" eventually develops, or are they two different things ? To conclude, perhaps our definitions of the I-function and of the 'self' are yet too limited to portray the reality behind the terms.

 I feel that the notion "all brains are 'somewhat the same, somewhat different'" is very logical.  Brains of humans and animals act similarly in that they keep us breathing and our blood flowing but humans have the ability to express emotion to each other while there is an ongoing debate on animal feelings.  While I am a bit unsure about the I-function, it allows us to locate the "person" in the case of someone like Christopher Reeves.  I feel that the I-function gets rather complicated when applied to patients in a vegetative state because how are we supposed to detect whether or not they know where their presence lies.  For people without Christopher Reeves' condition, does this mean the I-function lies in our brain? Or is it throughout our body because we are aware of all the parts of our bodies and are experiencing them?  What confuses me is how we talked about the fact that an I-function is not necessary for behavior, so does this mean the I-function lies in a separate compartment than the rest of the nervous system?

            On Thursday we discussed the notion that when you see something/someone you recognize, there is a pattern of activity across inputs. In other words, the same input activity would be involved in recognizing your grandmother and in recognizing a tree. I find this to be a very interesting concept. This logic would suggest there is an element of “pattern matching” we undergo. Specifically, when we see a familiar object, we (specifically what, I’m not sure!) matches the incoming inputs to a previously encountered pattern of inputs. In other words, we intake “A” and realize that “A” seems familiar to a previously received “A.”

            This makes me wonder about the mechanism of actual pattern matching. Do we all pattern-match at the same speed? Could this explain why some people are very adept at remembering names/faces/people while others really struggle with it? If someone has a super fast ability to access those memories of previous inputs, they will recall the similar “A” pattern quickly and be able to rapidly identify the familiar circumstances. I am curious to learn more about this, especially if the circumstances involve multiple senses (eg a smell/sound composition or sight/smell). I have heard that people’s sense of smell and sound most rapidly bring back memories, is this because those pathways are easier to recall?

            To build on this, what happens if the inputs are similar, but not the same. Say you encounter input A’, a similar but different set of inputs to the original pattern. Again, I would imagine that some people would quickly identify this as a hybridized version or the original, while others might not notice it at all or identify it as A. (This might explain why some people are so good at noticing when someone gets a haircut or slightly modifies their appearance). As we go forward I’m curious to learn more about memory and how we recall previous experiences. I hope everyone is having a good time with their web papers!

            I found it very interesting when we had talked about the brains being different amongst different organisms based on their behavior. I wouldn’t have expected the brains of all cats to be different based on the fact that they looked the same, which is not always a valid way of thinking. Then, when we talked about the difference between men and women, most of the class responded that there was a difference between them initially. When we further discussed this issue, it became apparent that there really was no specific difference between women and men, but there was a difference in a statistical point of view. We came to an understanding that the population distinction is unlike the individual distinction. For example, what all women are said to behave like can be what one man behaves like. I think I found this so interesting because usually men and women are characterized to behave so differently without any exceptions, so I would have expected there to be some difference in their brains. Another example that was used in the class that I found amusing was that some fish are able to change from female to male or vice versa depending on the social situations. This change in behavior resorts to a chance in the brain in a moment of days. Thus, in general all changes in behavior relate to changes in the brain.   

            I also agree with many of the other people when they say that the Christopher Reeve example was very helpful in understanding the behavior of neurons and the brain. I didn’t think that his foot would withdraw after being pinched, but rather it would stay still. If Christopher Reeve was told to move his leg, then the information would go to his brain, but there would be no cables linking to the motor neurons causing no movement.   

 Going back to Tuesday's class, I was especially interested in the idea that there is no actual human brain. Thinking about it, this idea actually makes perfect sense. Because there is so much variation amongst each of our brains, there can be no actual brain prototype which stipulates the characteristics of a human brain. Emily Dickinson's idea of the brain as encompassing all is supported by the fact that there is so much variation between individual human brains.

I also found the conversation about differences in male vs. female brains to be particularly intriguing. It is interesting that we are always taught of differences between males and females as strictly on a population-scale basis, one which cannot possibly account for all men and women, and which is thus still a stereotype. It puts an entirely new perspective on gender for me. What does it actually mean to be a male or a female if no biological or neurological traits can indefinitely be placed with one sex over the other. How is it possible to group genders into only two categories? 

The idea that behaviors are not ouputs, but actually a pattern of activity across lots of output elements makes a lot of sense in my opinion because behaviors are complex, if each possible behavior was connected to a unique output, the number of outputs would be enormous.Also, many behaviors, especially in humans, are not static, they change in response to circumstances. If behaviors were tied to specific outputs, how would they change? Building new outputs in order to change behaviors would be overly complicated. Patterns can easily be changed by substituting in different framework.

The "I-function" is an interesting idea. Certainly there are parts of the brain that can't be consciously controlled, and that more goes on in our brains than we are aware of, but it seems strange to put the concept of self in a box and separate it from the rest of the brain. I'm having trouble getting used to the idea that part of my brain isn't me. I wonder if it is a "box" in a sense that we might one day be able to pinpoint the part(s) of the brain that is the "I-function?" Or is it simply another way to explain consciousness? Do actions that we are conscious of involve neurons that are part of the "I-function?" Maybe the "I-function" is the part of the brain is different between individuals, and the parts of the brain that we are not aware of are the same. Though, how would we be able to tell if those other boxes were different, if we aren't consciously aware of their actions. Are the the ways that the neurons are connected different between individuals? Or is it the signals they send and times they send those signals that are different? 

After talking about Christopher Reeve in class, I decided to look him up.  Within the first paragraph of a Time magazine article, I found out that Reeve relied on a ventilator to breath.  As far as I know, the brain stem controls breathing.  However, Reeve's injury is between the first and second vertebrae.  This makes no sense to me.  I thought that because Reeve's brain stem was above C2 vertebrae, he should retain the ability to breath.  I guess I thought that breathing was controlled by the autonomic nervous system.  If his heart was still able to beat and he was conscious, then how could he not breath on his own?  I found another article saying that after intensive respiratory therapy, Reeve was able to breath on his own for about 30 minutes.  If he required a ventilator the rest of the time, and could not control his body below his injury, then how was this possible?  How can you train part of the body controlled by the brain and not yourself to do something?

If a sensation or a motion is caused by a pattern of activity across lots of output and input elements, does the "I-function" idea mean that our consciousness and self-awareness, "actions" of our mind are products of a pattern of activity across lots of output and input elements too? That there is a web of neuronal connections all relating to how we see ourselves that can be grouped together into a "box" called the I-function? What does that mean? Are all of our thoughts and feelings connected? I guess I still need some clarification.

One thing I thought was very interesting in class today was the idea that pain is a function of our brain. If pain is something our brain tells us we feel, are there ways we can tell our brain to not feel pain? Obviously some drugs can do this, but what about some sort of meditation, mental state sort of thing?I have had a sports injury for the past year and a half and it has more or less not gotten better at all. If there was a way to tell my brain not to feel pain, I would be able to play pain free! But, to be clear, I would not be healed. Pain is my brain telling me something is wrong with my body, so being able to block out those signals could do more harm than good. On another note, if there are rare cases of people in vegetative states where there is evidence of an active I-function, does this mean these people can feel pain?