Biology 202
Neurobiology and Behavior
Spring 2002

Forum Archive - Week 7

We've talked about action as motor symphonies, about central pattern generators, about corollary discharge, and about negative feedback loops. All neurons, organized by genetic influences and by experience, but starting to make more sense of what is between neurons and behavior? What do you think? What can we begin imagining we can account for? What is still hard to account for?


Name:  miranda
Username:  mcwhite@haverford.edu
Subject:  Christopher Reeves' motor symphony
Date:  2002-03-12 09:39:16
Message Id:  1486
Comments:
I think it is very helpful to think of the coordination of all the separate part of the nervous system as a motor symphony. For a body to function correctly, each motor neuron must do the right thing at the right time. What I'm interested in is, if we keep this analogy, how do we understand Christopher Reeves' condition? What is missing in his nervous system (or his motor symphony) so that it is unable to "play correctly?" He does not have control over the lower half of his body, yet his foot moves when pinched. We now know that even normal functioning nervous systems do not have a "conductor." So, is it just that his nervous system can't work together correctly?
Name:  Serendip Student
Subject:  in need of clarification...
Date:  2002-03-19 00:01:59
Message Id:  1518
Comments:
In regards to the brain having a filtration/ dividing system of sorts for reactions, I am unclear as to what this filter is actually (not what its doing) and where it actually is. The topic was touched upon briefly by a previous post and I realized that while I know of the action, I don't really know what is causing the action, if that makes sense.
Name:  Tara Monika Rajan
Username:  trajan@brynmawr.edu
Subject:  
Date:  2002-03-19 19:08:36
Message Id:  1522
Comments:
In class today we discussed the presence of a phantom limb. This concept seems very interesting to me because it shows that it is possible to feel something that doesn't physically exist. Therefore, we can feel things even if that physical part of the body is no longer there. This would mean that feeling a body part does not involve the body part itself, but instead involved the neurons and the motor symphony which is moving toward that part of the body. So if someone can feel their leg after is has been removed, it means that feeling the leg is feeling all of the neurons which pass the impulse to where the leg would be. Maybe feeling phantom pain would be somewhat like motion sickness, in that the neurons are sending action potential down a certain way to get the leg, but when they finally reach the end and there is no leg there, the body gets confused and feels pain.
Name:  Kathryn Rorer
Username:  krorer@brynmawr.edu
Subject:  
Date:  2002-03-20 01:40:43
Message Id:  1531
Comments:
So far we have done a pretty good job of describing how individual pieces of the nervous system work but I am still confused about how all these pieces fit together to make up human experience. The fact that action potentials can start without an external stimulus helps the brain=behavior theory a lot because it shows how thoughts can originate. This also suggests that people don't really have control over what they think about. However thinking consists of more than one thought, so what happens after the first action potential that causes other thoughts to come about? Is it that the first thought triggers the mind to remember previous knowledge related to the thought? How does this happen? The brain stores tremendous amounts of information. How can it quickly recall the relevant information? Then how do all these pieces fit together to make a new thought or idea? It seems very complicated.

Another piece that I find very interesting is proprioceptors and the idea that we might not experience certain activities in the brain yet they still affect how we feel and act. Could this be similar to the idea of an unconscious? Is it possible that our brain processes thoughts that we are not aware of? In the case of phermones, an action potential is generated because of chemicals in the air but it doesn't reach the "I" function. This is especially interesting since these signals may effect how we act and feel, yet we don't know why we would feel this way. If somethiing like this could occur with thoughts and memories it could be a sufficient explanation of the "something else" that many people feel needs to be added to the brain=behavior argument.


Name:  melissa hoban
Username:  mhoban@brynmawr.edu
Subject:  malfunction
Date:  2002-03-20 15:33:11
Message Id:  1544
Comments:
What happens if there is a malfunction in the conection of neurons? Not like that of the phantom limb, but rather in the central pattern generators. For instance if there is a missing conection in one of a persons pattern generators, therefore not giving the correct time delay in a motor function. Is this when one has muscle spasims or something of the sort?
Name:  Aly
Username:  adymkows@brynmawr.edu
Subject:  Question?
Date:  2002-03-24 19:54:38
Message Id:  1570
Comments:
Has anyone read anything on the British man who hooked his nervous system of his arm to a computer?? I read something briefly and would be very interested in hearing what others had to say about it.....
Name:  Paul Grobstein
Username:  pgrobste@brynmawr.edu
Subject:  getting rolling again
Date:  2002-03-24 21:58:36
Message Id:  1571
Comments:
Let's see, since spring break we've talked about action as motor symphonies, about central pattern generators, about corollary discharge, and about negative feedback loops. All neurons, organized by genetic influences and by experience, but starting to make more sense of what is between neurons and behavior? What do you think? What can we begin imagining we can account for? What is still hard to account for?

As always, the question is just to get you started if you need something. Other thoughts/stories/ideas welcome.


Name:  cb
Username:  cassbarnes@hotmail.com
Subject:  
Date:  2002-03-24 22:15:52
Message Id:  1572
Comments:
The interesting part about corollary discharge in my opinion, is that the circuits not only make sense of expectation and perception, but they make sense of choice without bringing in the I-function. This reminds me of things we refer to as muscle memory and smell evoking a memory. Is there a choice in recalling past time events when they occur like this? It seems like these inputs cause neurons to fire, which then lead to the thought and memory of something specific. Although, I suppose having inputs would not make this an internal generator.

There are motor scores stored in the nervous system and this internal communication influences the output. And things like muscle memory are just empatterned experiences which are evoked by the I-function. So then, if the central pattern generator is activated by the I-function, how can the body react before the I-function is aware of it?


Name:  Ricky
Username:  rtripp
Subject:  transplantation
Date:  2002-03-24 22:37:36
Message Id:  1573
Comments:
I think it is interesting to discover that the nervous system consist of the coordination of separate parts that have their own responsibilities somwhat separate form the whole and function as a motor symphony. It is understandable that each neuron should have a specific role and appropriate timing mechanism. My question dealing with this new aspect of motor symphony and neurons is what happens to neurons and motor symphony during transplantation. We talked somewhat about phantiom limbs and how a person may still feel the presence of a body part when it is not physically there. But what about the phenomena of people receiving organ transplants and having desires or cravings that have only been experienced by the host, who donated the organ to the recipient. There have been accounts from organ recipients that they feel things that they have never felt before, such as a long-term vegetarian began to start having craving for hamburgers after she received a liver. Also, how can body parts like hands be transplanted when they have an intricate network of nerves that must be re-connected to function? Will that transplanted hand or any other body part begin to feel like they belong to the person or does the body still consider them as foreign objects?
Name:  Beverly Weiss
Username:  BBWeiss
Subject:  phantom sensations
Date:  2002-03-25 10:40:50
Message Id:  1577
Comments:
I am fascinated by the concept of phantom pain.
Does the brain store and duplicate the sensations that were experienced or only the memory of sensation? Does the brain duplicate the pain, or only the memory of the pain? If the limb is absent, then the pain receptors from the limb are absent, so the sensation must come from the brain and not the limb. Are the sensory neurons in the spinal cord sending the message to the brain, or does the brain remember the sensory input without the interception of the sensory input from the spinal cord?
Name:  
Username:  Anonymous
Subject:  
Date:  2002-03-25 13:39:43
Message Id:  1579
Comments:
The topics discussed in the last week classes were eye opening and insightful to me. I was stricken by the similarity between how the nervous system operates and how a symphany works. There is a conductor(the circuit) that controls a medium(the nervous and the muscles)

The collarary discharge signals also give me more insight how the nervous system affects behavior. My question is, with regard to corrollary discharges, how come motion sickness occurs in certain individuals and not others. What accouts for it. Is it because certain individual's nervous system is better at the coordinating what the body expects to what is really going on?

-Cindy


Name:  Kelli
Username:  rdeering@brynmawr.edu
Subject:  thoughts
Date:  2002-03-25 14:44:33
Message Id:  1580
Comments:
I found that it is quite fascinating how central pattern generators store information to permit patterns of movements, as in the example of someone being able to perform a piece of music very quickly. Likewise, there are many processes in everyday life that at times seem to unfold without much conscious thought. I was wondering whether a "nervous habit" such as nail biting involves such CPGs, and if so, are they responsible for the difficulties experienced when attempting to break these habits? You often hear that it takes a month or so to "break a habit." Does it typically take such a measurable period of time exercise the nervous system in un-doing a CPG?

Also, during the discussion regarding phantom limb pain I began to think about syndromes in which an individual experiences the chronic and persistent sensation of pain while no physical damage is present at the site of pain. Why are these pain receptors being activated? Furthermore, is there a signal that the brain erroneously interprets as real pain?


Name:  Rebecca Roth
Username:  rroth@brynmawr.edu
Subject:  phantom limbs...
Date:  2002-03-25 16:06:59
Message Id:  1581
Comments:

Neural networks have to emphasize information gotten from the environment. People with the same inputs might in fact have very different experiences. Corollary discharge does help us make a sense of choice. Negative feedback loops act in a way which satisfies our main objective.

Are phantoms caused by changes in the flow of signals through circuits in the brain? People whose vision has been impaired by cataracts or by the loss of a portion of the visual processing system in the brain sometimes report highly detailed visual experiences, similar to phantom limbs. Also, people who lose their hearing commonly report noises in their heads. Do these phantom phenomenon occur when the brain loses its normal input from a sensory system? How do we make sense of all this?


Name:  Gabrielle
Username:  glapping@brynmawr.edu
Subject:  
Date:  2002-03-25 16:46:29
Message Id:  1582
Comments:
I would be interested in discussing what is choice now that we have changed some experiences that we thought were choice as corollary discharge. I am intrigued by the elimination of the I-function in this concept. Are there times when we are experiencing corollary discharge as if it is a choice? If so, that would bring the I-function back into the conversation. Then, there must be some secondary affect that the corollary discharge has on a sensory within the brain, of its own actions. That feels as if our brain is acting on its own, and allowing us to perceive those actions as if we decided to do them ourselves. I don't really think that is true, but its an interesting idea.
Name:  Hilary Hochman
Username:  hlhochman@aol.com
Subject:  mules and pleurobranchia
Date:  2002-03-25 17:20:43
Message Id:  1583
Comments:
There is a medieval parable about a mule, equidistant from two bales of hay, who starves to death -- without free will, a characteristic of the human soul,the mule cannot choose from which to eat first. I've never tried it, [no mule in the house usually], but suspect the mule just starts eating. Perhaps most of the time this could be accounted for by the mule perceiving one bale or the other first, but what if that variable were eliminated? The corollary discharge patterns and reafferent loops may explain much of what appears to be either conscious or random behavior [why is it so often so easy to confuse those two??], but it explains them by explaining them away. Are we really moving toward the position that their is neither choice nor randomness in behavior?
Name:  Amy Cunningham
Username:  acunning@brynmawr.edu
Subject:  
Date:  2002-03-25 18:54:07
Message Id:  1585
Comments:
I think that the discussion over the last couple of weeks has helped me to better understand the organization of the nervous system through the idea of the motor symphony and central pattern generation. However, I still feel like there are many variables that can go into the brain-behavior relationship: the example of the Pleurobranchea made me feel like we were right back where we started at the beginning of the semester, since we still can't predict what the animal will do. It makes me wonder how much we can know for certain about the workings of the nervous system, especially the "I-function" and the whole concept of experience? How do we know whether we really experience things? How do we know what other organisms are capable of experiencing?
Name:  Yasmin
Username:  ymashhho@brynmawr.edu
Subject:  
Date:  2002-03-25 18:54:16
Message Id:  1586
Comments:
I am fascinated by the concept of phantom pain. It is especially interesting when considering the fact that anyone who has lost a limb obviously knows, consciously, that they no longer have that particular appendage. They are aware of it. How, then, does the body simply overlook that, and continue to send signals towards the missing nerves? Its as though the body is in denial and keeps sending the impulses in the hopes that they would sometime be completed. Understandably the impulses must be sent, in accordance with the body's nervous system, but the fact that someone might actually feel an ache or a dull sensation as a result of those impulses is astounding. The tendency to feel the impulses and move our limbs is received, in part, from the central pattern generator, and also from the brain. I find it similarly intriguing that there is no way for us to consciously tell our brains that we are not feeling pain, that there is no limb there, and that the unpleasant sensations should cease, because there is no physical source of pain. Why does the brain not acknowledge that there is no body part, that the nerves will simply stop abruptly, without completing their course. I would think it would be reasonable that the central pattern generator would perceive this continuous problem, and rectify it, by not allowing the transferrence of pain sensations. Of course, I'm not sure whether the body can do that permanently, but it would be an interesting concept.
Name:  Asra
Username:  ahusain@brynmawr.edu
Subject:  
Date:  2002-03-25 20:48:53
Message Id:  1587
Comments:
Phantom pain is a very interesting concept. How is it that one can still feel where the position of their limb is if they don't have one? This is also true for those who weren't even born with one. This leads me to believe that we are all born with a few common "experiences" already in our brains.

An interesting article from Discover magazine addresses the phantom limb phenomenon in people born without a limb. Ronald Melzack, a psychologist of McGill University, believes that the brains has a map of the body independent of our life experiences and that a network of neurons forms in the embryonic brain to link the somatosensory thalamus and cortex (regions that enable us to sense the location of our limbs), the limbic system, which is involved in feeling pain and pleasure, and the association cortex, which helps us learn from our experiences. These connections prepare the embryonic brain to respond to body parts that do not always form. (Discover, Feb 1998)

So is this due to genetics?


Name:  Kathryn Fong
Username:  kfong@brynmawr.edu
Subject:  motion sickness
Date:  2002-03-25 21:00:33
Message Id:  1588
Comments:
I just have a quick thought. We talked about motion sickness and that it occurs when the corrolary discharge says one thing, but the motor sensory neurons say something else. For example, if one were standing in a boat, they boat would be rocking back and forth, so the motor sensory neurons receive that as input, however, the corrolary discharge don't pick up on the movement, since the person is just standing there. The disagreement causes motion sickness. But why is it that only certain people are prone to motion sickness, while others are not phased by it. Some people are able to tolerate turbulence, or the rocking motions of a boat, while other, like myself, get sick. If everyone's nervous system is just made of neurons and interneurons, why do certain people feel the effects, while others don't. Would motion sickness be due to a mutation or defect in the nervous system?
Name:  
Username:  arobbin@bmc-
Subject:  Asra's idea of "common experience"
Date:  2002-03-25 21:21:09
Message Id:  1589
Comments:
I found this idea that we all might be born with 'common experiences in our brains', as the last post suggested, very intriguing...especially in relation to the point of the article cited (that our brains already have 'maps' of our bodies and their parts before any of them develope (if they do at all))... really hits home the importance of our brains and their funcions in relation to the rest of our bodies. They are indeed the command center of our physical existance, as well as our psychological and emotional experience.
Name:  Mary Schlimme
Username:  Anonymous
Subject:  Starting to piece it together
Date:  2002-03-25 22:34:42
Message Id:  1590
Comments:
I've been thinking a lot lately about how much more appealing I find the brain = behavior postulation as the semester goes on. I think that our explanations using the motor symphonies, central pattern generators, and corollary discharge help explain many things that couldn't be accounted for in previous versions of our box model (in particular, they explain how things can start in the nervous system and how different parts of the nervous system communicate with one another). At first I was a little bit skeptical about our account of choice using the nervous system in a dish, but as the lecture continued it made more sense to me that choices are probably just neurons firing, even if at first they seem more complex than that. I also have a question after reading Kathryn's post I have some friends who suffer from motion sickness and need to sit in the front seat of the car so that they don't get sick during long car rides. After learning about the corollary discharge explanation of motion sickness, I'm wondering if this account can explain why they don't get sick when they sit in the front seat of the car, but feel nauseous when they ride in the back seat of the car. Or could it just be a psychological effect so that they perceive themselves as not getting sick in the front seat but getting sick in the back?
Name:  sook chan
Username:  schan@brynmawr.edu
Subject:  
Date:  2002-03-25 22:53:43
Message Id:  1591
Comments:
I found the topic about central pattern generators very interesting. As i was listening to the lecture during class, i realized how "generalized" we made the concept seem. It seems as if every person's motor activity would be the same, given similar motor coordinations of the motor neurons. Yet, what accounts for the differences in ability? When I was nine, my parents sent both myself and my brother to piano lessons. We both practiced an hour a day, and both were eager to play. The bone structure of our hands were very similar, yet, after four years, my brother was able to play beautiful pieces, and I "just did not have the musician in me". If the central pattern generators of finger movement and coordintion are similar between my brother and myself, why is it that i still am not able to play beautifully? Similarly, why is it that one child is able to run faster than another?

I also found the idea about phantom limbs very interesting, and would like to learn more about this concept.


Name:  Sujatha Sebastian
Username:  ssebasti@brynmawr.edu
Subject:  What does choice signify?...
Date:  2002-03-25 23:21:44
Message Id:  1592
Comments:
In our last class discussion we looked at the organization in the nervous system that make nudibranch mollusks respond to stimuli. While I found this converation thoroughly enlightening... it was not until we questioned what the mollusk's deision to choose to respond to that stimuli signified, that I began to understand the importance of our discussion. What does choice and the decision to respond to a stimuli indicate? Prof. Grobstein said that choice can account for the behavior that we observe in an organism, but that it cannot account for the experience that we believe that the organism is having. It is that one comment that I took away with me on Thursday. I must admit seeing that comment as being applicable to much more than just the case of our nudibranch mollusk. On a continuing note I ask (and realize that this question may not have an answer)what does account for experience? And are we the only ones who can define our own experiences?
Name:  Shannon Lee
Username:  kitsumi12@hotmail.com
Subject:  the sixth sense and memory
Date:  2002-03-25 23:35:58
Message Id:  1593
Comments:
I am now realizing there is so much more to what is between brain and behavior than I had imagined. There is so much complexity. I did not even realize a "haptic system" existed. To think there is a sixth sense that I did not even realize makes me think of brain and behavior in many new ways, evoking many new questions. Waterman's loss of the sixth sense and the idea that he could not move around, without watching and consistently consciously trying, is interesting. It has made me start watching my movements and feedback to constant stimulus I didn't realize I was receiving. I did not realize I could lose the feeling of knowing where my leg is when not seeing it. I thought this was the sense of feeling, the same that experiences a pressure on the leg when I push on it with my hand. I will have to spend more time thinking about this because, although I am sure I now have a clearer understanding of brain and behavior, I feel even more overwhelmed and ignorant of the issue than previously.

I do have a thought concerning memory that does not seem to have yet been accounted for concerning brain and behavior. We know that experience has a lot to do with pattern generator, as well as genetics, but what decides what is to be scripted into the conscious and unconscious memory. Also how is a memory stored? Is it equal to a number of action potentials fired by a specific pattern of neurons? How does this new pattern get scripted in and develop? I know that if I consciously try to learn something, the brain takes over to somehow program it into the brain, but what about the many memories of small detail that we never consciously decided were important? Which set of neurons in my brain decide it is important enough to subconsciously script the memory of my grandmother with the sight or thought of a dandelion, but then resist me when my conscious tells the neurons to remember everything there is to know about physics?


Name:  Shannon Lee
Username:  kitsumi12@hotmail.com
Subject:  the sixth sense and memory
Date:  2002-03-25 23:36:47
Message Id:  1594
Comments:
I am now realizing there is so much more to what is between brain and behavior than I had imagined. There is so much complexity. I did not even realize a "haptic system" existed. To think there is a sixth sense that I did not even realize makes me think of brain and behavior in many new ways, evoking many new questions. Waterman's loss of the sixth sense and the idea that he could not move around, without watching and consistently consciously trying, is interesting. It has made me start watching my movements and feedback to constant stimulus I didn't realize I was receiving. I did not realize I could lose the feeling of knowing where my leg is when not seeing it. I thought this was the sense of feeling, the same that experiences a pressure on the leg when I push on it with my hand. I will have to spend more time thinking about this because, although I am sure I now have a clearer understanding of brain and behavior, I feel even more overwhelmed and ignorant of the issue than previously.

I do have a thought concerning memory that does not seem to have yet been accounted for concerning brain and behavior. We know that experience has a lot to do with pattern generator, as well as genetics, but what decides what is to be scripted into the conscious and unconscious memory. Also how is a memory stored? Is it equal to a number of action potentials fired by a specific pattern of neurons? How does this new pattern get scripted in and develop? I know that if I consciously try to learn something, the brain takes over to somehow program it into the brain, but what about the many memories of small detail that we never consciously decided were important? Which set of neurons in my brain decide it is important enough to subconsciously script the memory of my grandmother with the sight or thought of a dandelion, but then resist me when my conscious tells the neurons to remember everything there is to know about physics?


Name:  Balpreet Bhogal
Username:  bbhogal@brynmawr.edu
Subject:  
Date:  2002-03-26 00:07:52
Message Id:  1595
Comments:
The topic that interested me the most last week was the discussion about choice and whether or not the influence of one part of the nervous system on another part of the nervous system is what we mean by choice- whether or not a choice is determined by signals and the inhibition of signals. It was also interesting how this correlated to the I-Function and the experience of making a choice. I think what fascinates me the most is the fact that I never really thought of choices to be so detailed, in that it relates to signals, such minute things compared to the human body as a whole. This discussion has made me think about choices in a different aspect. A choice is not constricted to whether you're going to order chinese takeout or pizza. It goes all the way to signals and the inhibitions of signals. I just wanted to say that this was a very interesting topic in my opinion, and that it actually made me ponder the idea of choices entirely.
Name:  Gavin Imperato
Username:  gimperat@haverford.edu
Subject:  
Date:  2002-03-26 01:44:16
Message Id:  1596
Comments:
I am very interested in Sook's earlier comment about the "generalization" of the concept of central pattern generation. The idea of individual difference intrigues me, and I'm wondering if there is any way to completely understand how a given action or thought is affected by genetic differences, differences in knowledge, or differences in experience. I seem to recall that in an earlier class we discussed the notion of the tremendous variability that can be found in human brains. How then, can we account for the sometimes astounding similarities we see in the thought patterns of different people? How would studies on cloned human beings affect our current understandings? When the "parts" are the same, what does this really mean in practical terms?

Our discussion of the idea of choice made clearer for me how specific signals and brain activity correlate to behaviors, but I am still unsure how these models can attempt to explain much more complex human thought and emotion. If our knowledge of neurobiology won't allow for this at the present time, will we ever understand it? What more needs to be worked out?


Name:  priya
Username:  psp22@hotmail.com
Subject:  questions
Date:  2002-03-26 08:58:48
Message Id:  1597
Comments:
I found the discussion on pattern generators interesting and I've been trying to figure out how much of human behavior can be avccounted for by such a model. In doing so I realize that the model leaves more out than it includes. How does it account for variations? I realize how choice can be dictated by neural pattern generators, but what I'm talking about is behaviors that are patterns, but are different amongst groups of people. Language being only one such example. Other questions that I have are:
How does such a model account for creativity?
How does such a model account for learned behavior and memory?
How does such a model account for large changes behavior that animals make in response to the environment?
Name:  Serendip Student
Subject:  schizophrenia
Date:  2002-03-26 09:47:37
Message Id:  1598
Comments:
With the buzz about "A Beautiful Mind" lately, I've begun to wonder about about the genetic implications of schizophrenia. Schizophrenia is a serious disorder that impairs a person's behavior and hinders the activity of the breain and I-function. I vaguely know that there is a chance for the disorder to be passed onto offspring, but I don't know the genetic details. My genetic inquiry also extends to other disorders that hinder the brain in some way.
Name:  Nicole
Username:  npietras@brynmawr.edu
Subject:  
Date:  2002-03-26 15:39:46
Message Id:  1599
Comments:
On tuesday we discussed how thought is just a bunch of action potentials. It makes sense to me just thinking about thought, but when I start thinking about how our brains solve math problems or reason out problems, then I have a problem grasping that idea of thought being action potentials. I guess I'm still stuck on the big picture (ie. the brain) than the small picture (ie. action potentials and nerves). On some level i know that the brain is just a bunch of nerves, but I am still having problems. Perhaps some of our future discussions will shed some light upon this.
Name:  Lauren
Username:  Lauren_welsh@hotmail.com
Subject:  tues class
Date:  2002-03-26 19:07:37
Message Id:  1600
Comments:
How are we so similar? We have been focusing on the differences and I think it IS important to pay some attention to the similarities. I think it is amazing how nature can create such intricate organisms that all happend to be so similar. I think that culture and having some similar basic needs can make all organisms on earth closely related, but sometimes I ponder over the intimate moments and thoughts I have had with others. It seems like we can be so like others in feelings, opinions, and physically, yet so different at the same time - but the similarities are definitely the amazing part of the human experience.

In class we also talked about whether or not we could determine for sure that other organisms (humans included) were experiancing pain? It is true that we have no way to know for sure that a dog, an earthworm, or even our own brother is experiencing pain because there is no way to test for internal experiences. However, how is it that we all think that we are discussing this?????
How do you know you are experiencing pain if there is no comparison and no way to know for sure that you are talking about something that happens to others or even yourself? With language we are able to discuss and describe, yes, but that can not equate to real experience - truth, language has it's limits.

I'd say we are assuming that we have internal experiences of pain just as we are assuming others aren't.


Name:  Sarah Eberhardt
Username:  idy3176@yahoo.com
Subject:  Choice and pain
Date:  2002-03-26 22:53:38
Message Id:  1604
Comments:
The concept of choice as a matter to be decided solely by neurons disturbs me, but I can't really see any other explanation for behavior such as the nudibranch's. I do wonder, though, where the line of "conscious decision" is drawn. Exactly how do humans draw on their experiences, their consciousness, to make complex decisions? At what point does a set of actions constitute a "behavior," and when does it become a decision that must be made consciously?

The issue discussed on Tuesday about perception of pain versus behavior indicating pain is an interesting one. If one argues that we can't know if animals such as cats and dogs feel pain because they are incapable of telling us of their personal experience, then one could also argue that babies are incapable of feeling pain. Babies cry, much as animals make their respective noises of pain or unhappiness, but babies cannot tell us what they are experiencing. Indeed, the first year of life is not remembered when the child grows older. It is entirely possible, according to these guidelines, that babies do not really feel pain, however unhappy they may become. Another problem with this argument is that chimps who are taught sign language ARE capable of expressing their experiences to us, however simple they may be.


Name:  Miriam Shiferaw
Username:  mshifera@brynmawr.edu
Subject:  
Date:  2002-03-27 00:25:19
Message Id:  1606
Comments:
I'm reading people's thoughts about pain and how we can only tell if someone is in pain if they tell us, so how do we know animals feel pain? Maybe I'm missing the main point, but it seems simple to me. When I feel pain, like when I accidently bang my toe against the leg of a desk, I wince and frown my eyebrows, the same universal facial expression most people make when they are in pain. Or if someone is pinching me really hard on my arm, I will shake my arm so that they'll get off of me. I think it's obvious then for me to tell when someone else, even some animals like cats and dogs, is in pain. Words don't necessarily need to be spoken for us to know everything, or communicate with someone else. I wrote my first web paper on aphasia, the language disorder, and a lot of what I read mentioned our habit of neglecting nonverbal communication. There are many people with this disorder and others with other illnesses that cause them to lack the ability to speak. When a baby cries it can mean many things, but if you're hurting the baby, it probably means they are in pain. I think if we exercised our right hemisphere more often, the side where we think more creatively and our nonverbal communication skills are developed, it wouldn't be so hard to understand if and when a dog or cat feels pain. I guess we only have our external indicators and signs of pain to rely on, because how can we really internally test if someone is experiencing pain?
Name:  miranda
Username:  mcwhite@haverford.edu
Subject:  animal's and pain
Date:  2002-03-27 11:55:49
Message Id:  1616
Comments:
I undertand that we can not know for sure that animals feel pain. We cannot ask them how they are feeling or necesarily infer from their noises and body language what they are experiencing. However, it seems extremely likely to me that animals feel pain in much the same way as humans. Many animals have very similar nervous systems to us that physically respond very much like ours (i.e. increased blood pressure, perspiration, increased pulse rate, etc.) Also, we know that all animals nervous systems evolved in much the same way as ours. It would certainly be evolutionarily advantageous to experience pain, as it allows animals to avoid painful stimuli. So, though I know that we can not be certain what it is that an animal feels, I think we can be pretty sure that it is not so different from what we feel.
Name:  Tara Monika Rajan
Username:  trajan@brynmawr.edu
Subject:  animals and pain
Date:  2002-03-27 21:28:16
Message Id:  1625
Comments:
To me it seems that while we may never know for sure if an animal feels pain or not, it does seem likely that they do. When a human being and a cat are burned in a fire, they act the same way, besides the fact that the human can talk and therefore can verbalize exactly how he or she feels. However, supposing the human in the fire is unable to speak for some reason, maybe she is mute, we would still assume that she feels pain from the burns. This seems to be the same situation for the cat. While it cannot speak, it still reacts to painful inputs the same way as people do. If we understand that humans feel pain, then it seems logical to also understand that animals feel pain. One interesting question that arises from this i, how far down the evolutionary tree can we go until we get to an organism that does not feel pain? Where can we draw the line? Is the general concensus that any animal without a nervous system does not feel pain? And how do we know this for sure?
Name:  Aly D
Username:  adymkows@brynmawr.edu
Subject:  Pain pain and more pain
Date:  2002-03-27 23:50:01
Message Id:  1628
Comments:
The whole discussion of whether we are able to know if animals feel pain and if we are even able to know whether another individual feels pain is easy to get caught up in. I feel like it turns into an answerless debate. It reminds me of my college seminar discussion on Descartes. Descartes became so enraveled in his thoughts that he began to question his own existence in its entirety. However, he stopped when he came to the realization of "I think therefore I am". We should take cues from this and think about the situation reasonably. It is likely that because we are all members of the same species, we do feel pain (unless an individual is injured or has some sort of mutation.)

I agree with the statements made previously by others. The similarities in the structure of the nervous systems of animals to that of humans hint that they all function similarly. Therefore, I would be willing to put money on the argument that animals do feel pain. In class it was argued that although Christopher Reeve responded to pain, he did not FEEL it. Was this supposed to be evidence against animals feeling pain? I think it is only evidence that a paralized animal could not FEEL pain, not a completely healthy one. However, like Tara, I need to question how far down the evolutionary path the feeling of pain would go for animals. Was the anaesthetizing of the leech unnecessary? Or is the leech uncapable of feeling pain?


Name:  Tua
Username:  schaudhu@brynmawr.edu
Subject:  Pain:response and experience
Date:  2002-03-28 10:20:07
Message Id:  1632
Comments:
The concept that pain is the discomfort you feel when your nervous system's expectations do not match the information given to it by sensory neurons is really interesting. Also fascinating is the idea that there is a difference between a response to pain and the experiencing of it. Christopher Reeves' toe responds to the pain of being pinched, but Christopher Reeves does not experience the pain. The connection between the sensory neurons and the i function box which registers experience has been severed, in this case, by an accident. But what about, as we were discussing in class on Tuesday, those who walk on hot coals or sleep on beds of nails? What about this concept of "mind over body"? Do people have the ability to control which signals get sent to the i-function box? When we walk, a certain motor symphony is playing in our nervous system. Often when there's an obstruction we can walk past it without really thinking about it, so if disturbed the motor symphony can reacclimate itself. Experience often dictates the expectations of the brain. So, is walking on hot coals without being burnt or experiencing and responding to it achieved by simply doing it over and over again until the brain expects the hot coals? Or is it more a matter of inhibiting the sensory signals which yell burning feet get off the hot coals? Does this mean that we can decrease or eliminate pain by acclimating our brains to the experience of it?




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