Neurobiology and Behavior, Week 3

In talking about inputs, outputs, interneurons and the brain=behavior idea in class, we mentioned homeostasis behaviors, such as the intake of air to the lungs, pumping blood through ventricles and arteries, etc. These are behaviors that come about in response to inputs of which we are unconscious.

In the human visual system, there are two fairly separate pathways by which information in the visual field reaches our consciousness. 90% of visual information travels along the geniculostriate pathway, synapsing on the lateral geniculat nucleus before ending in the striate cortex (the primary visual part of the cortex). Because information reaches the visual cortex, this is what we see consciously--we are aware of it because it has reached the cortex. The other 10% of our visual information comes by way of the tectopulvinar pathway, synapsing on the pulvinar nucleus and then the thalamus. It never reaches the cortex. This allows for some patients to experience "cortical blindness;" patients with damage to the visual cortex but not the tectopulvinar pathway are completely blind as far as visual information of which they are conscious, but when something moves within their visual field, they are still able to react to a movement, without being conscious of having seen it.

Relating this to class, where do reflexive behaviors and conscious responses (outputs) to unconscious inputs fit in to the box model? At what point within the spaghetti web of interneurons does information go from unconscious to cortexual and conscious? How does this play into the brain=behavior question? I would think that it is very good evidence for brain=behavior because it provides a conscious, neural response in the form of behavior to something which, without the complex workings of the brain and neural pathways, would not warrant such a behavioral, albeit reflexive, response.

In class this week, we learned something about the structure of nerves.  Nerves are a bundle of axons, cell bodies and dendrites are absent.  They carry signals from one location in the nervous system to another in the body.  These signals can travel in both directions along nerves.  Next, I began thinking about what can go wrong with nerves.  Particularly how to make sense of a herniated disk.  A herniated disk occurs when the spinal disk slips out of place and pushes against spinal nerves.  This situation results in a significant amount of pain, amongst other things.   So the pain is a symptom of an anatomical problem. What I would like to know about all this is how do pain medications work?  Especially, drugs like vicodin and percoset.   How do these chemicals interact with the nervous system and affect signaling?  I am hoping for an explanation beyond basic biochemistry...

So maybe Dickinson is looking at me right now going "I told you so".

This box theory is proving that it really is the physical matter of the brain that is controlling our behavior. It is as wide than the sky in the sense that our brain has a wide capacity to hold and process all sorts of information and as the nerves in our eyes are responsible for seeing the sky. However the content of the brain isn't the only thing that is important; by looking at the brains of different animals, size and structure are also critical to behavior. We behave very differently from a frog, not because we have different material from them but because that material is structured differently. This makes a very strong case that brain=behavior, along with the face that about 99% of the brain's neurons are interneurons (receive and send signals within the nervous system where the outside world has no effect), that Dickinson's view holds true. But I've been a believer that the "mind" (emotions, consciousness, etc.) is  embedded within the "brain" (physical matter). Perhaps this is the begginning to finding that proof, or at least an answer? 

I was personally very interested in the discussions that we had about the morphological differences that exist between not only the brains of different species, but also between those of different genders within organisms of the same species.  What is most perplexing to me is the stimulus which causes these differences.  The traditional scientific approach would lead one to believe that this morphological change was sparked by a chance mutation in one’s genetic makeup.  However, what is to say that one’s thinking and own collection of thoughts was not the impetus for this change in morphology.  By pushing the brink of one’s traditional means of thinking or attempting to focus one’s mental capacities in particular ways, could an individual alter the physical structure of his or her brain.   From the discussions that we have had thus far in class, I am convinced that this may be entirely possible.     

In class we discussed the self generated outputs that our brain creates, and this reminded me of my internal voice. She sounds a lot like me, and helps me rationalize about a lot of things like wants vs. needs, what assignments I need to do instead of playing video games, etc. So my internal voice keeps me on track, so to say.

However, is this a self generated output or my unconscious reacting to daily stresses such as homework, budgeting, family problems, etc? my internal voice and I have out own conversations - I promise I don't have disassociative personality disorder - I wouldn't know about my internal voice then, now would I? However, what is it? Is it my unconscious? My neurons firing up because they're bored? Or is it something that just doesn't exist but I consider to be a part of me?

Learning about how many boxes each person can be broken down into surprised me. I obviously know that everyone is different, whether it is physically or mentally, but I never stopped to think just how many different people there are. With about 1,000,000,000,000 neurons in our bodies that can account for differences, it's mind-blowing to realize. Our planet can replicate multiple times and still have everyone occupying it be different. The thing that bothers me is that if me and another person only have a difference in one or two neurons, will it really make that big a difference? If so, then how?

As the class conversation progresses, it seems more and more evident that humans, due to their self-awareness, engage reality in a give and take relationship. Matter and the laws of science come to us, we understand and master them, and then we manipulate them. The law of gravity, for example, is a basic law of nature that revealed itself to us (through that ever-important apple that bruised Sir Isaac Newton's head, and in turn left a mark on the head of humanity). We quantified it through physics and mathematics (which also "came to us"), and we manipulated it (as we do on a daily basis, from the dump truck to the study of aeronautics). This manipulation is where creativity comes into play. 

Someone is class, I'm sorry  I don't know your name, brought up Da Vinci and his flying machine. Certainly Da Vinci was a man of astounding intelligence and his machine was as novel an idea as they come, but his creativity existed not in some fantastic, original output lacking an input. It existed in his ability to combine and manipulate myriad inputs he perceived over time. In other words, his creative output was in fact a function of numerous inputs throughout his life: his education in mathematics and physics, his acquired knowledge of craftmanship, his love of birds (I don't know this for sure. Just an example) etc. Creativity comes down to an ability to combine. Creative ideas are a function of memory and the human ability to problem solve.

This leaves open the possibility that some people are naturally more creative than others as they have more accurate memories and can combine ideas and concepts more fluidly. Some people are better at thinking "outside the box" (pun intended).

This argument relates to the idea of outputs without inputs. Do they really exist?  Or is there just a time lapse between certain inputs and their respective processing? Some inputs may not generate a direct and immediate output. Also, various inputs (i.e. observations that we add to our grand summary, our concept of reality) can be called upon long after they have been perceived in a creative combination of sorts (such as Da Vinci's flying machine).

Going forward, I am very interested in the effect language has on the interpretation of matter and general reality and, in turn, how this effect plays into creativity. Language is one of the pillars of every society, thus it has a dramatic effect on how one looks at the world. Prof. Grobstein, if you are reading this, any suggestions for books on language and/or creativity? Thanks.

When people talk about thinking they often use the term "neurons firing," but given what we're learnt in class I'm not sure how thought process connects to neurons. Do thoughts develop in some type of complex interconnected chain like neurons? Do thoughts have some type of material substance in the brain? When I think that brain= behavior I imagine that thoughts must made out of some material substance. But from what? I can't imagine that neurotransmitters are responsible for the complexity and breadth of human thought, but at the same time I feel like the complexity of neuron architecture may be involved. When patients are given tasks, different areas of the brain will light up according to what they are doing. So maybe thinking involves different parts of the brain, like the frontal lobe and temporal lobe, interacting with each other. I looked this up online and it seems like it may be true. I came across a study that argued that creative thought comes from areas of the brain connecting that normally would not connect. I think this makes sense, especially given what I've learnt about neuron architecture and individuality. Differences in neuron architecture would allow areas of the brain to connect in unique ways, allowing for individuality and creative thought.

In class on Thursday, it was mentioned that much of our actions, or I suppose what would be considered outputs, are a result of activity generated from within the nervous system. How does the nervous system generate an input all on its own? Is there something such as an input generating an input? Or perhaps a stimulus for an input? We defined input to the nervous system as something that activates sensory neurons. So perhaps sensory neurons are responsible for activating sensory neurons, which reminds me of the idea of boxes going all the way down forever…

  Also if most of our actions are dictated from within the nervous system, does this mean that everything outside the brain is just a construct of our imagination? Perhaps Dickinson would think so. I have a hard time accepting the implications of this, in the fact that physical objects are seen almost uniformly by  all people. Everyone can identify a chair, and has associated the image of a chair with certain actions, such as sitting down. Although everyone has a unique brain, why do we behave in a predictable manner in specific situations? It would seem that since there are an almost infinite amount of combinations of neurons, which are each their own “computer”, that all humans would be vastly different, and any foundations, such as social norms, would not exist. Given the fact that they do exist, perhaps outside influences such as culture and social norms tend to even things out, and account for the similarities in behavior among specific groups of people. But in general given the variations in neuron architecture that exist between humans, it's pretty mind boggling to think we can all co-exist (for the most part).

To begin with, I am interested in our continuous conversation regarding the boxes that spontaneously generate outputs. It seems like these boxes still receive some sort of input, it's just not an input that comes from outside the nervous system. In other words the input to these boxes does not conform to our class definition of input as something that activates sensory neurons (which have dendrites outside NS). The sensory neurons accounts for physical sensations-touch, smell, taste, etc., but what about emotional sensations? How is it that people feel depressed? Does that require an input from outside the nervous system? How do we explain the connection between hormones-which are present in the brain-and our behavior? Another question I have is where dreams fit in to the box? Are sensations felt during dreams based on memories of past sensations? If so, then how come people can feel like they are flying, a sensation that they have never actually had? Are dreams an example of an output produced by a box with no inputs?

On a different note, I was thinking back to Thursday's discussion regarding the three different types of neurons and how the vast majority of neurons are inter-neurons. I was wondering if it would be possible to have an organism with only motor and sensory neurons? Would this be a "brainless" or "mindless" organism?  

Beyond thinking about the difference in the structure of the brain from animal to animal and the influence that has on behavior, I am interested in the way in which the structure of brains differs from person to person.

I was most interested in the observation that 99.9% of neurons are interneurons so that Dickinson's argument for the constructedness of our surroundings, the creation of experiences in our brain, seemed to be supported. There is the additional observation, then, that all of the neurons in the neocortex are interneurons.

Somebody asked on last week's forum what the purpose of memory is. I always think about the quote that you only ever see the same thing once, and the idea that from that point on every observation, even of the exact same thing, will be through the lens of the experience before that. In this way, if this statement is correct (and the ratio of interneurons to sensory/motor neurons suggest that it may be) then our experiences are always simultaneously memories. 

The neocortex is unique to mammals, and in class last week we started a conversation about what distinguished mammals with a neocortex from other animal groups. Is there a more balanced ratio between sensory and motor neurons and interneurons in animals whose nervous systems do not have a neocortex? 

     After our talk on Tuesday I felt really great knowing that no one else had my brain. It made me think about this struggle for individuality that everyone has or certain people focus their entire lives on. I first that well since none of us have the same brain does that not already make us individual enough? but then I come to think that maybe the struggle for individuality is not so much about the contruction of the different parts of our brains but more so about the way we may share similar outputs to certain words, situations, etc. That led to the idea or myth of twins sharing thoughts or people sharing thoughts. What is that does that mean that certain parts of peoples brains can be similar? Or does that too also account for cultures and the environment in which they exist? Ultimately does anyone ever reach this state of "individuality" and what is it really if not mental?

     Also, looking at the idea of the bigest box and what seems to be the input for that I would have to agree that the outside world and everthing around it is an inout. Touch, taste, smell, things that we see, feel, etc. This makes sense because the closest way we could replicate taking out of the nervouse system from all types of input (like the leech experiment) is sensory deprivation. If you are removing all forms of sense then in a way you are ridding all external inputs right?