Biology 202 Neurobiology and Behavior Spring 2002

So ... we've got input/output boxes inside input/output boxes, LOTS of them. And brains which seem to differ in organisms who behave differently. What does that do for our "brain=behavior" discussion?

So ... we've got input/output boxes inside input/output boxes, LOTS of them. And brains which seem to differ in organisms who behave differently. What does that do for our "brain=behavior" discussion?

We know that different organisms behave differently. Since different organims behave differently is it because their brains are different? Or is it because there is more going on?

Breaking down the components of the brain and behavior is useful, but it is also becomes very complicated. Afterall, the brain is composed of different parts. One can combine different information and get different results; therefore getting different outputs. Now would this just be leading to different behaviors?

In the examples, the boxes have to process the input. So what is coming out of the box, which would be the output, may not be what exactly what goes into the box. To me, our experiences and prior behaviors are always going to effect these outputs.

How does the brain understand what exactly these inputs are? How does the brain and nervous system know exactly what to do? Wouldn't there have to be other outside behaviors and responses coming in?

Since the input is filtered down to smaller and smaller components, does input change as it progresses down to the next smaller level, or is the message delivered in its entirety along its axonal path until it is received by the brain and then processed in the appropriate area of the brain? Do all messages reach the brain in only one form, as an “on or off” chemical response of the neurotransmitter?

After the neurotransmitter is processed by the brain and sent off to the peripheral nervous system, are the outputs also an on/off reaction, or do mitigating factors have the ability to change the output? If this message relay system is all due to chemical reactions in the synaptic cleft, where does the DNA affect behavior?

There does not appear to be any conscious awareness of this process, and it happens in a microscopic amount of time, whether the “animal” is asleep or awake. Since this system is chemically fueled, at what point in this process do living creatures (no matter how sophisticated) make decisions? What happens in the tiniest box that allows for the output not to need any input? How can it generate input from within?

There are boxes inside bigger boxes and so on, and the littlest boxes symbolize nerve cells (which also contain parts of the cell). Between the arrows is the box, (or between the neurons is the synapse) the box that we know not much about. We know that this box does not need to have input. So, it seems to me that this box constitutes such things as thinking, conscious and unconscious, and perhaps dreaming thinking. Does it follow then, that thinking occurs between the synapses?

So this means that there are boxes that require input. That is, for some thinking, input is needed, and for other thinking, input is not needed. And so, does it mean that between the arrows, or between the neurons, thinking occurs… and that this is due to the synaptic transmission? If this is the case, then solo box, the one without the input can create its own thinking own synaptic transmission.

Thus, if we simply think about something negative (without any input), like a person cutting us off on the highway, causing a near death experience, then we can cause the release of corticosteroids, which then cause stress and a feeling of negative emotion? Does that mean that first we think, then we feel? It seems to me that this view is open not only to Biologists.

Back to the animals…. if we have these kinds of boxes in our brains which incorporate thinking, then do animals think too?

The idea that brain = behavior is also supported by the fact that organisms that behave differently often have differently structured brains. For instance a cat has a much smaller forebrain than a human and also relies more on instinct in life than humans. A human is known to suppress the instinctual drives with the more complex forebrain and depend more on analyzing and problem solving skills in life. The forebrain is also a newly evolved portion of the brain, which offers explanation on why humans have depended less on instinct and more on complex thought process as the species has evolved.

Also the cat, which has a neocortex, is able to develop a sense of loyalty and affinity toward other animals including humans, even those not responsible for feeding the animal. The frog, however, will never enjoy or be emotionally rewarded from sitting on the lap of a human and being stroked on the head. The frog depends even less on emotion and more on instinct than a cat while carrying out its daily activities. If the presence of a neocortex suggests more complex thought process and more emotional attachments, then differences in brain structure influencing differences in behavior supports that brain = behavior.

I began thinking about the neurological degenerative diseases like Alzheimer's and wonder how many pathways must have been destroyed or terminated because of the disease? How many pathways does it take before you can no longer have access to long-term memory or to not be able to perform daily activities like brushing your hair or eating with a fork? How does the brain change with these diseases?

On to the comparison of brains information.... From examining slices of brain tissue, we observed that the compositon of the brain was almost alike. So what does that information tell us? Well,it first verifies the theory of evolution since we all seem to be made up of the same materials. Second, I believe that it helps with the brain=behavior dispute because we see that as the behavior becomes more complex so does the brain. The frog, camel, ant, snake, and etc., who have smaller brains in size, seem to have behaviors that seem more simple to humans. With the human brain, I believe we have more complexity dealing with decision-making, will, emotion, and others. I am not saying that other animals do not have emotions but there doesn't seem to be a intricate process in expressing them. For isntance, a dog wags his tail when he is happy/ friendly; however, a human may smile at you and it could mean that they a delighted to meet you, just smiling to hide they are talking badly about you, or just thinking about themselves and showing the world they are happy not necessarily with you. I believe that the increase wrinkles of the neocortex symbolizes more room or space for behavior to change. In accordance to the model, it allows more space for movement of neurons and pathways to the boxes. Looking at the behavior of animals, we all seem to share a basic behaviors such as hunger and searching for food, reproduction, and death. However, there is more variation in behavior as the brain becomes bigger and more wrinkled such as deciding to cook food than hunt or, instead of mating with some partner, going to a sperm bank or invitro. Those are just some thoughts.......

Perhaps, although the brain tissues at a high magnification do look similar to each other, it is the way the brain tissue interacts with each other in general that causes the differentiation of species' behavior. For example, if you had two buckets of Lego with the same exact pieces in each bucket, you could find more than one way to use them. You could make a ship, or a plane; or maybe even a building or a house. But even though these structures were made from the exact same pieces, they ARE different structures. Perhaps this is why although the brain tissues are similar at a high magnification, the species still behave differently from each other.

maybe there is an outside blueprint that accounts for the building parts AND for the various differences between you and me...or us and them. the whole idea of a greater blueprint overlying everything has always seemed very cool and at the same time kind of uncomfortable for me. if i can see a blueprint or a plan in the greater scheme of the world, what does that mean about my beliefs? do i believe in a god, who created a "blueprint" that is too huge for us to see, so huge that it encompasses space and the universe all the way down to cells, or does it mean that the world was created in an ordered way and that order goes all the way up from cells to the solar system and god is simply one more part of this universe created in the minds or hearts of those who believe?

when the people in class who have been bringing up religion start talking about how the brain=behavior doesn't account for religion, i have to say, so what? i have always felt like religion is something humans created and have adapted our lives around. i don't disbelieve in god, but if this being does exist, then he/she exists in ourselves. it's not something you can prove. it's something you believe in.

it's not like the mere existence of religion should blow the argument brain=behavior out of the water just because you can't fit religion-as-autonomous into it. it actually kind of reaffirms my feelings that the brain does equal behavior because if you believe in god, supposedly what you believe in should affect your behavior. god is a belief that not everybody has, so why should the fact that this model may not account for god mean that this model is not less wrong?

hehehe...i don't really want to re-read that to make sure my double negs add up...but do you know what i mean?

Similarly, what seems like a deeply emotional response can be explained by the organization of neurons transmitting information from the environment: a familiar smell often evokes memories and emotion much more effectively than a familiar sight or sound. Turns out that the olfactory nerves transmit much more directly to the limbic system than do visual or auditory sensory nerves. Nauta, W.J.H. and Feirtag, M. The organization of the brain. Scientific American, September, 1979. Stack the neurons differently and it would be vision that created such an emotional response, and the domino effect on behavior would begin.

The boxes all the way down model, however, does not offer [to me] as satisfying an explanation for the Harvard Rule of Animal Behavior. We can account for any living organism's unpredictable behavior by attributing that apparent unpredictability to our ignorance. If we knew enough about the organism's brain, and could control all external input, perhaps the behavior would be entirely predictable. Neuroanatomy is destiny. But what this model seems to omit is randomness. Perhaps sometimes there is no reason for a behavior, no neurobiological explanation -- maybe sometimes the cricket just doesn't sing, and if you looked at his brain and his environment, there'd be no way to say why.

    After reading the article, I realized that the hypothalamus is a good example of a smaller box processing the input of food( or lack of) and effecting the out put of behavior, which is whether to eat less or to eat more. According to the article, fat cells produce a protein called leptin and the leptin comunicates to the hypothalamus which then regulates metabolism. Leptin is manufactured by the gene OB. If the gene is defective, then the protein will also be defective, resultling in inrregular regulation of behavior(food intake)

Just as there are different ways to arrange the neurons in our brain. There are also different ways that our genes are arranged. Therefore, there is no surprise that defective genes of leptin does occur.

i was wandering, how does the box diagram account for the affect of genes on our brains that effects our behaviour. I was also wandering, if a person decide to control their appetite dispute the effect of the hypothamus telling them to eat. Which boxes is responsible for this "stubborn" behavior.

What I find interesting is the distinctions that cannot be explained by differences in brain size or structure. Why is it that people react diffferently to the same situation. For the most part, human brains of the same gender are similar. There can be differences in the amount of certain neurotransmitters or hormones that can effect mood, but I think a large part of the differences can be explained by learning. This then goes back to the nature versus nurture question. Inevitably, I think that both have a large part that contributes to the behavior of an animal.

Ricky said it best in message #810: "What happens if one of our paths just breaks down? Will that breakdown affect the other paths? Will we still be able to perform the same output if a path breaksdown?...How many pathways does it take before you can no longer have access to long-term memory or to not be able to perform daily activities like brushing your hair or eating with a fork? How does the brain change with these diseases?"

This excerpt stood out because this is probably one of my biggest fears of old age. I've often wondered why with age, people become virtually unrecognizable to themselves and their loved ones. The complexities and systematic nature of the brain reaffirms my fear and the possibility of it becoming a reality. To add to the flurry of questions, what is involved with the evolution of the brain? How many of these critical pathways can I count on, or do some naturally breakdown from illnesses caused by old age.

Essentially I'm left wondering -- how long will I (my brain) have control over my own behavior. Should I expect to gradually forfeit said control over time? But then what am I scared of, time or my own brain? The more questions I pose, the more I convince myself that my brain isn't a fascinating mystery, but a scary feature, autonomous of all logic, reason and most of all - control.

(i obtained the more technical information from these websites http://peace.saumag.edu/faculty/Kardas/Courses/GPWeiten/C3BioBases/Cerebrum.html
http://www.epub.org.br/cm/n01/arquitet/cortex_i.htm
http://serendipstudio.org/bb/kinser/Int5.html)

However,there were some things about the model that I didn't think it did a good job of explaining. One thing is where does thinking and decision making come in? How does it work? How does a thought originate within the system without input? Or does there always have to be some type of input that triggers a thought? How do dreams and imagination fit into the box model? Are there boxes for each of these things? The box model seems a little to simple to explain how these processes work, unless they are incorporated within it and I'm just not seeing it.

Someone previously mentioned that the size of the brain affects thinking, which makes me question whether that would mean animals like whales and dolphins had greater thinking capacities than humans. I often wonder if animals do indeed think like us. If our brains are all made up of the same building blocks, i.e. neurons, then I don't understand why the concept of animals thinking is so impossible to fathom. Well, actually I do. It would be much harder to eat a big cheeseburger if it were suddenly widely accepted that cows had the same thoughts and emotions as people.

I would really like to see how the brain is affected by mental illnesses and Alzheimer’s disease. Like many, I fear aging and fear that if brain really does equal behavior, then how will my behavior change as my brain deteriorates with age? The thought of losing my behavior makes me feel as if I am losing my sense of self, which frankly scares me so much that I do not want to think about it.

- It is interesting to note that although the brain seems to differ in
organisms who behave differently, when the brain is sliced and
magnified, one discovers that the brain essentially came into being by
similar means in different organisms.

I can think of the brain as the basic ingredients for a cake. Every organism starts out with the basics, such as flour, eggs, water, butter, milk, and so on. But everyone (or everything) has different preferences (or rather what they need to survive and produce viable offspring). This means that on top of the basic ingredients someone (or something) may want more butter or more eggs (accounting for the different sizes of similar parts in different organisms). So simpler things will stop here with a simple cake. But as someone gets more experienced (or furthur down the evolutionary chain), things get more complicated. There are the addition of new ingredients, and the addition of new instructions.

- It seems to me that there is another way to intrepret "the boxes within
boxes model."

Rather than interpret the boxes as different parts of the brain, one could think of the boxes as different experiences that the brain has organized (?) into different categories. The brain uses experience as a reference to explain and affect future experieces. So when there is an input into the brain, the brain sends this to the boxes (experiences) that pertain to the input being experienced presently. Because each person has had differnt experiences and are made of different ingredients, outputs will vary.

- What about the box that can generate without input?

It seems that this box could be something such as the development of puberty. It is just a matter of time for the event to occur independantly of experience, action, thought, it is an innate body function.

- Summary of thoughts:

The introduction of the new observation that brains seem to differ in organisms who behave differently and 'the boxes within boxes model' seem to supplement the idea that brain = behavior. When first presented with this idea, we were posed with the question, if brain = behavior, then why are brains different. These new ideas, I think, make it more comfortable for people who did not agree with brain = behavior to better understand that it is not as dry cut as when first presented.

In response to this comment by Prof. Grobstein, I must dispel any assumption that I have made any sense of the world, let alone explained it!

After several days of ruminating about the 1/24/02 Brain=Behavior discussion, I am no closer to any conclusion. I have always considered the brain a processing unit; data is input, processed, and then output, output being behavior. The input varies and includes intangibles (feelings, thoughts, emotions) as well as tangibles (body chemicals, pharmaceuticals). The product of the brain is =behavior.

I believe in the existence of the soul and, heretofore, have seen no need to prove, disprove, or defend its existence. Where does conscience fit it? Is it part of the soul, or the brain? Is it measurable? Is the soul measurable? How? When? Where? I believe that input to the
Brain= Behavior (which is output that has been processed) but the Brain=Behavior theory seems to be an oversimplification of a very complex question.

Questions about processing data that is input into the brain further complicate the issue. Is all information processed in the same way? Although we choose much of the brain¡¯s output depending on our choice of response (behavior), there are some remaining questions. What about other output (i.e., reflex reactions, addictions)? Are these behaviors attributable to output without input? Are they spontaneous reactions? Chosen responses? What and how are the differences measured?

After Thursday¡¯s discussion, we have boxes and animals and a variety of different brains. We have more information and new observations, but the original statement continues to intrigue me (Brain=Behavior).

As class discussion continued, the increasing number of boxes in decreasing sizes led me to new observations. These new observations lead to new questions. OK! So what! Different brains = different behavior. Further discussions reveal that all brain matter is composed of neurons that are basically the same but are configured differently so that different species will process information in different ways. This information does not provide any new knowledge about how the input is processed by each individual species.

One final comment¡­.

Past experience further limits my conviction that brain=behavior. There have been times when it seemed to me that brains had little (or nothing) to do with behavior.

The only way to resolve the variability and similarity between and amongst living things is to examine the nature of the biological basis of life itself?genetics. It is genetics that determines the development of the neural system in all organisms. In casual conversation an individual?s odd behavior is sometimes attributed to how he/she is ?wired.? It is the genetic code that determines the initial wiring of the neural system in any organism. This is not to say that once this wiring has been programmed it exists in vacuum uninfluenced by external factors. Variability in neurological development is not only a factor of ?intrinsic variability? as dictated by the genetic code; it is also a result of adaptations to external stimuli (the environment). In addition, it is important to recognize that these two factors do not exist independently of one another. On the one hand, it is possible to see how a single neuron in a mouse and a human can be so similar because there are only 4 molecules that code for the formation of a neuron. On the other hand, it is hard to imagine that all the diversity in the natural world is a product of the combination of 4 molecules that make up the genetic alphabet. This is especially true considering that the percentage of the human genome that overlaps with certain species of primates is over 90%. Nevertheless, together these characteristics indicate that the smallest differences at the molecular level have significant implications at the macroscopic level. So, relating this back to the brain=behavior argument, I would change the equation to include genetics and the environment (genetics àßenvironment)àbrain=behavior). I find that the idea of complexity and diversity out of simplicity is initially a difficult concept to grasp given that as human we see ourselves the pinnacle of the natural world. Even so, when one accepts this to be true the models such a boxes in smaller boxes in even smaller boxes makes sense because it follows the pattern that exists throughout the natural world.

A few random thoughts:

In ?conversations with Niel?s Brain? the doctors manage to get predictable output by directly stimulating specific regions of the brain. More specifically, the doctors get output while isolating the input. What are the implications of this?

How does one explain yogis who are able to control their rate of breathing by controlling their minds and focusing their energy?

How does on account for being in a certain ?state of mind??

I?m not sure that the input/output box model and brain=behavior theory are capable of addressing these issues.

| Course Home Page | Course Forum | Brain and Behavior | Serendip Home |