Forum Archive - Week 5-6
How useful are concepts like "central pattern generation", "corollary discharge", "proprioception and reafference", "genetic and environmental influences" in making sense of "action"? in what ways might one use these ideas as well to better understand other aspects of nervous system organization/behavior?
Name: Paul Grobstein
Subject: week 5
Date: Tue Feb 20 16:36:37 EST 2001
So ... I thought you'd be working on your web paper, no? And hence you don't HAVE to write in the forum this week. But, if you'd LIKE to write here, you're more than welcome. Of course. On anything that has occurred to you since you last wrote. Last week's comments, as usual, have been moved to their own .
Date: Wed Feb 21 01:52:38 EST 2001
A friend, to whom Ive been brain-dumping much of the interesting stuff we're kicking around in class, sent this quote to me. "If the human brain were so simple that we could understand it, we would be so simple we couldnt"
Date: Thu Feb 22 13:09:02 EST 2001
Who-a. We don't believe in reflexes in this course? What is meant by this? We certainly can observe a phenomena such as the knee jerk, or sucking in babies -- are you saying that we describe the causal chain differently than the people who call that phenomena "reflex?" Question: If we close our eyes, we can probably state pretty accurately the position of our various body parts -- is this part of the Proprioceptor sensory system or something else? if its part of the proporioceptor system, would that imply that at least some of that system can function at the level of the "I function?"
Date: Mon Feb 26 20:38:57 EST 2001
I found this regarding the comments made in class.
"During stage 1, which is light sleep, we drift in and out of sleep and can be awakened easily...People awakened from stage 1 sleep often remember fragmented visual images. Many also experience sudden muscle contractions called hypnic myoclonia, often preceded by a sensation of starting to fall. These sudden movements are similar to the "jump" we make when startled."
Brain Basics:Understanding Sleep
Subject: some thoughts at 4:30 am on a Tuesday morning
Date: Tue Feb 27 04:59:08 EST 2001
Isn't it so odd, when you think about it, how random all of our explorations of thought and mental disorders, etc. are? I mean, to what extent can we REALLY prove any of this? Specifically, I am writing my paper on Dissociative Identity Disorder (more commonly known as Multiple Personality Disorder), and I was very surprised when I realized how much information there is out there questioning the mere existence of the disease. What is truly interesting is that, in reading that arguments, they make sense. It would certainly be possible for a psychiatrist to lead patients on or even for the patient to lead him/herself to believe that he/she is suffering from one disorder or another. This is particularly true in terms of diseases such as DID, where the only real way to diagnose is through questioning the patient.....and the methods used most certainly leave room for "creativity" on the part of either the doctor or the patient. The number of cases of the cultivation of false memories by psychiatrists and therapists, and the subsequent lawsuits (one woman "remembered" her father sexually abusing her as a child and impregnating her-- these memories resulted in his having to resign from his position as a clergyman, only to subsequently discover that his daughter was a virgin at had never been pregnant). In a legal and societal sense, the implications of this are profound! Can you possibly justify accepting this diagnosis (or similar other ones, for that matter) as support for acquitting someone, even though it obviously relatively simple to falsify? Then, one must also extend this same reasoning to any other situation-- how do we really know what is going on within the minds/brains/I-functions of other people? WE DON'T, and that is kind of an amazing though (trite as it may be).... So, I guess what I'm trying to say, as we desperately attempt to "understand" the brain or at least get things less wrong, is this: what does it all mean? how much of our findings on neurons and neurotransmitters and MRI's can we really trust until we experience the various disorders for ourselves? Sure, there's increased brain activity here and there, and many many people report feeling a certain way (take DID or even the feeling of falling in stage 1 of sleep), but how much of it could just be the power of suggestion or false memories or just people wanting to be creative or feeling trapped in a lie? what do we do with this information? it's kind of interesting, i think...
Subject: Dreams and learning
Date: Tue Feb 27 10:56:13 EST 2001
I would just like to comment on the web paper process. There is way too much information out there and it is so difficult to separate the good from the bad. I started out thinking I was going to write on dreams but it was crazy so I gave up and switiched my topic. But the one thing I like about this course is that you can make so many connections. After rewriting my paper on the learning process, and how our brain changes when we learn, I started to question what happens during dreams. Do we change our brain permanently? When we learn a skill, we practice and practice to get better at it, and our brain changes and creates a pathway that remembers this skills and makes it easier for us to recall when we need to - what happens when we have reoccuring dreams - are we in a way developing a skill of having that certain dream? Do we learn to have dreams? Maybe this can be my next topic . . .
Name: Paul Grobstein
Subject: week 6
Date: Sun Mar 4 10:55:18 EST 2001
So ... its been a while since most of you left your thoughts here. And a lot has been talked about since (at least that's my feeling). Basically, we've spent two weeks trying to make sense of things above the level of the neurons by looking at the output side of the nervous system. From which we've gotten the ideas of
You are, as always, free to write about anything that struck you as interesting. But, if you need some incentive: how useful are these concepts in making sense of "action"? in what ways might one use them to better understand other aspects of nervous system organization/behavior?
- action as a "motor symphony"
- proprioception and reafference
- central pattern generation
- genetic and environmental influences
- distributed control
- corollary discharge = efference copy
- influences of corollary discharge on "perception"
- corollary discharge as creating "expectations" for input
Name: caroline ridgway
Date: Sun Mar 4 18:26:41 EST 2001
Considering these concepts helps to parse "action" into its constituent
"boxes." It is easier to understand the whole when the individual pieces can be separated and simplified. But does this really provide an accurate depiction of behavior as it is manifested in an observable form? Yes, behavior arises from action potentials and every other property of neuronal communucation. But, more specifically, behavior arises from the complex interactions among all those properties. Furthermore, simplifying behavior into neurotransmitters and membrane potentials incorrectly ignores the important influence of context. That the nervous system is capable of such a high level of complexity is remarkable, but what is yet more remarkable is that the possible behavioral iterations become even more infinite when the influence of the external environment is factored in. The simple systems approach is beneficial in terms of understanding neural functioning to a certain extent, but it isn't likely that the depths of the human nervous system can be reached this way.
Given the complexity of the nervous system, it is impressive that so little goes wrong, generally speaking. The wide variety of topics covered in the web papers from last week may reflect, in part, some of the ways in which the nervous system is capable of malfunctioning. I find the ways in which the different parts of the nervous system work together to achieve one end to be much more interesting than the ways in which each separate unit functions independently. To me, one of the most striking things about the nervous system is that it seems so arbitrary and yet so coordinated. What, evolutionarily speaking, motivated it to become organized in the way that it did? It may be that the only way to understand the whole of the nervous system, both its inputs and its outputs, may be to examine each smaller "box" such that the bigger "box" might be accurately constructed, with deference towards a possible biggest "box," made up of both nervous system activity and contextual influence, that may as of yet escape definition
Name: isabella obazee
Subject: Brain equals behavior and much more!!!
Date: Sun Mar 4 20:43:56 EST 2001
Brain equals behavior and much more!!!
Yes, I'm stepping outside of what I usually believed to be an equivalent relationship. While I believe that all of behavior can be accounted for by the organization and function of the brain. I also believe that the brain can do much more than account for our behavior. It can also account for others behavior.
Has anyone ever heard of this creepy character? Well, while I'm still trying to decipher an experience I had approx. two and a half weeks ago. I have not thought much about it until today, while browsing through past web papers. I came across a paper about sleep paralysis and awareness of sleep paralysis (ASP). I was happy to find an explanation for this experience that I have way, way to often (at least 1 a week or once every two weeks)!!! It involves being in a normal paralyzed state during REM sleep, but then awaking to conciousness and being unable to move any part of your body. The information that I have read on this says that people can only move their eyes. My experience is that I can barely move my eyes (they just flutter a lot in my attempt to wake myself up) I also experience a burning in my chest as a result of trying to wake up. It kind of feels like I'm doing some damage to myself, but I do pretty often and when I wake up I don't feel any different, so I'm probably not doing to much damage. I can also lift my head a little bit. It's pretty bad because the experience reminds me of an infant just learning to lift its head. The experience is pretty stressful, so sometimes I just let myself fall back asleep and say I'll wake up whenever. Usually, I am trying to wake myself up from a bad dream or a nap.
Anyway, recently I had the experience during an ASP session that somebody was there in the room with me…on my bed. I could feel this person's breath and they were trying to kiss me! It was a horrible experience because I thought somebody was there, well I knew nobody could have been there because it wasn't a dream, and I just could believe that there could be another being in the room with me. I vaguely remember them saying something, but all I could feel was there breath and their presence. I forced myself to wake up by trying to open my eyes and move my head, and after who knows how long I woke up and noticed that there wasn't anything next to me, except of course my E.T. doll. I gave the doll a strange look, and felt a burning in my chest, from trying to wake myself up. Needless to say I took some time before going back to sleep.
Upon reading this ASP paper, I read that this is an experience that occurs almost 30% of the time to ASP experiencers, not only that, but there is a name for my particular experience:
Incubus/Succubus: An Incubus is a spirit/demon that seeks sex with sleeping females while a Succubus
is a spirit/demon that seeks sex with sleeping males.
How horrible that this is a well-known (it is described by scientists and others interested in dreaming and sleep)!!!
Fortunately that was my only experience like that…with "incubus." A time when my brain seemed to create more than my behavior!!
Just thought i'd share that with you all :o)
Date: Sun Mar 4 21:09:37 EST 2001
If corollary discharge signals affect the sensory input side, how can anyone know what is really happening in the world? If corollary discharge signals move backwards and "override" the signals from the "I" function, how does the brain determine what to ignore and what to interpret as reality? Is there some innate knowledge or predisposed genetic coding, where some inputs can occur while others are impossible? But this can't be true in all cases, because the brain interprets some images that shifts on the retina as not moving. Should humans start to doubt their perception of things, because we don't know when or if the input is altered by corollary discharge signals? What if this implies that humans do experience all of reality, but the corollary discharge adjusts it for humans. Perhaps, if it weren't for these signals, there wouldn't be such a perceptual difference between humans and other animals. Although, corollary discharge signals can be an amazing check system, indicating when something is wrong with the nervous system, but I can't help but feel cheated of experiencing some inputs in their rawest form, like colors and smells.
I guess it also depends on your interpretation of reality. Corollary discharge signals support the idea that reality is just the way in which the brain interprets input. But this view implies that there are different realities for every person, because everyone has a unique brain. But if you believe that there is one reality shared by all, corollary discharge signals are difficult to make sense of, as seen when we discussed phantom limbs. The reality of the person with the phantom limb is that there is pain in the region where the physical arm used to be. But the reality of others is that there is no arm and therefore there are no sensory receptors to interpret that pain and provide verification of the location of the arm. This returns me back to the issue of having receptors specific to a sensory input, differing humans and some animals in which they have certain recpetors for such inputs while humans may not. So what is reality?
Subject: Corollary Discharge
Date: Sun Mar 4 23:02:44 EST 2001
I was wondering when the corollary discharge actually takes control during perception? When we were talking about what determines perception, we decided that it is controlled by both things that come into the nervous system and things inside the nervous system, but what controls what part? Or is there a certain distinction? Do the inputs from the outside and the insides overlap?
I think that corollary discharge is a good way to explain why we all percieve things so differently, but what triggers the discharge and why do we need such an internal control? Why isn't the external input we recieve enough for us to know what is going on around us?
I guess I still have so many questions that I hope we can answer...
Name: Kate Lauber
Date: Sun Mar 4 23:18:59 EST 2001
I'm in a seminar for seniors concentrating in Neuro-Science. We mainly discuss articles that have had a large impact on the field. This week, I'm presenting two articles on the addictive properties of marajuana. Reading these articles brought me back to the begining of the class when we talked about how neuroscience is a "fence-sitters" discipline. I guess I feel like knowledge about the brain can either be incredibly clarifying on an issue, or make you feel like you have no idea about anything. In one of these articles, they relate marajuana's addictive properties to heroine's because they both activate dopamine release in the nucleus accumbens. The other side to this issue is that almost EVERYTHING pleasurable releases dopamine in that area. Sex, chocolate, you name it. How do we ever know what's what? Magnitude of effects is one thing, but I feel like the deeper you dig in this discipline the less you actually know for sure. Anyone else?
Subject: Your focus determines your reality. Huh?
Date: Mon Mar 5 00:49:28 EST 2001
Perception, it seems to be something that is unique for each individual. We speculate that it is governed by the inputs and outputs that flow through the array of ‘boxes’ that make up our nervous system. Different people often perceive the same input in completely different ways, outputs change and behavior changes from individual to individual. This is no big surprise, with the vast number of ‘boxes’ and the varying connections between them; seemingly infinite numbers of individual perceptions could result. Yet, in a lot of cases, humans as a species tend to perceive things and react in a constant and non-unique manner. In fact, law enforcement agencies count on this when on the trail of serial killers. Though each killer has different motives and methods, profilers are able to predict their age range, job bracket, attitudes towards various inputs and a variety of other details that we tend to think are unique to ourselves. Sometime the profiles of a killer end up looking like something a psychic put together; the type and color of they car he’s driving, his relationship with mother or girlfriend, events in his life that could have precipitated his acts of violence, etc. Yet, more often than not, these detailed profiles match when the killer is finally caught and speculation compared with reality.
To make the educated guessed they do, profilers have studied numerous other cases and found similarities between them. But to be able to guess the make and color of their quarry’s car seems impossible, almost like a magic trick. Sometimes I think there is less individuality in individuals than we were lead to believe. Our ‘unique’ likes and dislikes sometimes aren’t spontaneous; they’re the result of inputs that other people react in similar ways to. Yet, then again, there is proof of the opposite. Study of serial killers show that they are often the result of abusive families. But why do some abused children grow up to be humanitarians while others grow up to be Ted Bundy? I suppose that until we can find more information on ourselves and how our perception works, a lot of our behavior will have to be attributed to the mixed bag that is the I-box. Still, each person is not as different from the other as we think.
Name: Alexis Webb
Subject: Mind over Matter
Date: Mon Mar 5 01:06:45 EST 2001
Dealing with the annoyance and misery of having bronchitis for the last week and a half has made me start thinking about how we deal with stimuli, including illness. How often do you hear the phrase 'mind over matter'? Now this often refers to some physical obstacle that we face in the outside world. But isn't the brain and the biological processes that take place there 'matter'? The majority of discussion presented thus far has focused on this very problem: equating physicallity with abstract things, like self or behavior. Is 'mind over matter' really 'matter over matter'? If self is linked to the brain then it's biology's fault we can't accomplish everything we want to do.
So, could I have recovered from my illness without taking antibiotics, and instead willing myself to feel better? Would the brain biologically compensate for the desired behavior of health? There is something to the psychosomatic nature of illness, and even hypochondria. When we feel sick it is sometimes a state of mind. And it's possible that this state of mind is a physical state. Maybe. Regardless of the answer, I find the idea interesting.
Subject: Central Pattern Generation and the ability to learn
Date: Mon Mar 5 07:59:23 EST 2001
When we were talking about flying not being a learned behavior, I took a little while to think about it and then I realized how true it is. There are many baby birds raised without contact to other birds (pet stores) and they all learn how to fly. When I was younger I found a 2day old baby Robin in my backyard and I raised him to adulthood. When you were describing the natural trials and errors that the baby birds go through in the nest (trying to fly), I could not relate this to my experience. I found that, Chirpy (my bird), was more interested in learning how to strengthen his legs, rather than his wings. But as soon as he had enough feathers he started to fly. I think this is a result of not having to fly from the nest, to get to the ground. Since we let Chirpy walk around the floor, he had no need to fly until he wanted to explore more. Hopping was the skill that he worked on the most.
Thinking about the same sort of CPG, is talking a learned experience or will everyone talk eventually. It seems to me that is must be learned because languages are different, and little kids are must more receptive to learning new languages. This must be because there are certain areas in the brain which have the potential to be patterned at a young age, but as we get older the brain and nervous system are less receptive to changes in behavior. I wonder about this, because I have a 2 and 1/2 year old nephyw who still isn't talking. There are a few words he can say, but mostly he just babbles. Unlike most little kids, when I try to encourage him to sound out words, he refuses. He seems not to want to learn how to talk. I wonder if it has to do with him being the second born and getting what he wants without clearly asking for it. I try to tell him that the only way he will get anything, is if he asks for it in English. He understands everything I say, it seems, but he is reluctant to learn more.
This intrigues me because it might mean that the connection between the CPG and the brain and nervous system occur at different times during the life cycle.
Name: Sadie White
Date: Mon Mar 5 12:44:08 EST 2001
It's quite interesting to consider the central pattern generating capabilities of the CNS. I wonder if any of the genes that encode the necessary developmental information have been isolated. Or could it be a "gene symphony" that is responsdible for the numerous motor symphonies organisms undergo? In any case, it seems to be a gray area. I wonder which types of behavior are generated by "motor symphonies," and where the hypothetical line can be drawn between the genetic and the experiential.
This raises in me a question regarding learning. I know that we spent some time in class discussing the idea that learning occurs when connections are made within the brain that were not previously there - a gradual movement toward greater unity between the parts of the brain, perhaps? However, I was wondering if the notion of the genetic basis of central pattern generation can be expanded to other functions of the brain, such as learning. While genetics can be considered a factor in CPG, then why couldn't it analogously be responsible for other parts of behavior, as well? In that case, are certain people genetically better learners than others? The same question could theoretically be posed to any human behavior. Where does genetics lose sway over behavior, or vice-versa?
Like your intuition that it is a "gene symphony" rather than a gene. And yes, genetics contributes to lots of things in addition to (some) central pattern generators. To talk about more as the course goes on. In the meanwhile, have a look at http://serendip.brynmawr.edu/gen_beh.
Subject: random thoughts
Date: Mon Mar 5 13:27:27 EST 2001
The recent discussion has elaborated on the point that the nervous system stores a lot of information about action. This raises questions concerning free will again. The motor symphony is mostly preprogrammed and I do not see a great amount of possible control. I understand that experiencing new stimuli will result in altered responses, but again how much control does the I-function have over this? Maybe the idea of free will is not an accurate description for human behavior. There needs to be something else that is narrower, yet still accounts for the variety of behavior found in all people. I do not know what this might be, but further discussion in class could reveal the present unknown.
On a different note, I find the whole concept of central pattern generation very fascinating. The nervous system stores so much information and is able to access all of it at incredible speeds. I think this aids in explaining how computers work. Each store information and utilize it in various processes. If a computer were to have as many interconnections as the nervous system would it become self-aware? I have always wondered about this because of some books I have read. In one called The Moon is a Harsh Mistress as more ports and functions are given to the computer it becomes conscious. I think this would be a very valuable experiment to try because it could offer insight into how we ourselves become self-aware.
Those are all of the thoughts floating around in my head for now. I'm sure more will come tomorrow after class.
Name: avis brennan
Subject: more on brain and behavior
Date: Mon Mar 5 14:42:42 EST 2001
Looking through the web papers, I was struck by how much everyone can discuss something that nobody really knows the first thing about. I agree with Caroline and Kate, in that the more I learn about the function of the brain, the more difficult it becomes to make generalizations about how such function is related to behavior. While the general pattern of box-to-box communication is relatively clear to me, I find it both fascinating and frustrating that I can’t make more causal relations between input and output. It seems there are so many different ways signals can be divided, re-routed, regulated and summated, that we won’t ever be able to break-down the steps of processing and response. So is there a point to trying to figure out all these intricacies? Is it better to try to understand things in simplistic terms, such as the box model, or does this interpretation rob the neural system of some of its integrity? Is it better to have drugs that act somewhat mysteriously on our systems than nothing at all? This raises greater questions about how we even approach biological processes. It seems to me that we research questions about the physiology of the body assuming that our minds are capable of grasping the complexity of such mechanisms. This logic places inherent boundaries on our discussion of mind, brain and behavior.
Name: Daniel Burdick
Subject: Internal v. external perception
Date: Mon Mar 5 19:01:12 EST 2001
So I guess Aristotle loses and Plato wins. Reality can't possibly be
accessible to our perception, as Aristotle hoped. Not only have we learned
that there's a vast amount of reality that escapes our sensory neurons, now
we find out that our perception of reality depends to a great extent on the
outputs generated by our own nervous system! Shadows on a cave wall is
seeming like a better and better analogy.
In fact, this makes me wonder what the whole nervous system is for. I had
always assumed that its main goal was gathering information about our
environment, but if our glimmer of reality is affected by proprioceptive
information, efferent copies, prior experience, and even transient mood
changes, then it seems that the nervous system isn't necessarily doing a
great job of keeping us in touch with the outside world. It's more as
though the nervous system is keeping us in touch with ourselves,
"ourselves" including as a very small part our position in and relation to
the outside world. But the nervous system doesn't seem at all concerned
with accuracy in representing reality; it only has to do a good enough job
to make sure we don't get killed, we can find food, and we can recognize a
mate. In some ways, this is a little discouraging...but then, that's just
my perception of it at the moment.
To touch briefly on Claire's question about learning language, I can share
that it seems that children do in fact learn just about anything better
because the composition of some key neuronal receptors is different. I
could try to explain what I remember, but it's probably better to just
provide a link to the article I read, which is accessible through Serendip's
collection of Scientific American articles. The article, Building a
Brainier Mouse, is written by Joe Tsien, the Princeton University researcher who
created a strain of "smart mice."
And finally, since I'm having a lot of fun since I learned how to create
links: neuroscience hits the funny pages - a look at sensory perception a
Name: Alice Goff
Subject: The Storage Box
Date: Mon Mar 5 19:36:02 EST 2001
Amazingly enough, I am not having too much trouble interpreting action through the neuronal processes we've been discussing. Action seems fairly relevant to impulses and potentials as we've talked about. What still seems to be hazy in my mind is the problem of how information is stored. Does everything that goes through our nervous system come popping right out? Experience doesn't seem to point to this. We all have memory, right? When an actor memorizes lines in a play, she does this in order to be able to summon them up at a later date, not for immediate use. I realize that this is perhaps opening up a whole new can of worms I shouldn't be touching right now, but thus far every process we've talked about has been one that results in an immediate output. What allowance is there for delay?
This issue of storage brings into question what exactly the nervous system is for. Like Daniel, it's purpose as indicated by what we understand of its function seems to contradict how I know it from living with it for 18 years. It seems as though it is kind of a vending machine-- you put something in, you get something out and occasionally it randomly gives you free things. But what about that all too familiar use of the brain as a big box of knowledge and fact, none of which directly results in behavior?
Date: Mon Mar 5 19:53:25 EST 2001
Just a quick note before I leave my thoughts on this weeks topic, in response to comments left about incubus and succubus. I have done a bit of study upon the subject from a purly literary point of view, and just thought I might leave a few words about that background. The incubus is a demon figure closely associated with the vampire. The experiance, which was described above, varied from extreme pleasure to absolute terror. The lore of the incubus is thought to have originated in the ancient practice of incubation, where a person went to the temple of a deity and slept there over night. In the course of the stay the person would have what was labeled as sacred marriage, or intercourse, with the deity in the form of the high priest or priestess. When the Christians came to power, they equated the practice and the gods themselves with devilish demons. During the Inquisition, the practices of the incubus was related to witch craft, and those experiancing their presence were often tried and put to death, assuming that all witches would willingly give into them. Throughout time, Nuns seem to have been highly preyed upon by the creature, for they would often blame their sudden pregnancy upon it. Just a few thoughts. How do I think this relates to neurobiology, well, if we look only at the facts I have given, it would seem that it doesn't, for these are all just humanity's way of getting around their own fears and flaws by blaming the supernatural. However, there is one point, slightly removed that I do wonder about, that is in the institution of "sacred marriage", people would often travel to the temples and have intercourse with the "deity" in order to heal themselves of some illness. It is my inference, that in order for this practice to continue, their must have been some cases in which the participant did become well again. My question is can we explain such occurances as self healing through pure thought, by using the subjects we have been exploring these past few weeks. Does mind over matter really work, and if so, how can a person heal themselves with only the belief that they will be healed? This of course is assuming that no deity actually was present. But I know there have been several instances in which a person has been told that their condition is an incurable one, and then through will and belief in an outside force they are healed. Now I know that some religious people will say that it is the work of a god on the lives of his faithful, but how would that account for a pagan worshiper being cured. Is there a mechanism in the brain which could create such an occurance?
Name: Euree Choi
Subject: Is this for real?
Date: Mon Mar 5 20:06:14 EST 2001
Earlier in the semester, I found an article about ecstasy titled "Cracking Down on Ecstasy" in the U.S. News magazine (February 5, 2001). I was really interested in the minor section within this article entitled "Ecstatic? Maybe. But not without risks" (http://www.usnews.com/usnews/issue/010205/ecstasy.b.htm). This article stumbled into my mind after reading some student comments. The article explains that ecstasy drains serotonin from the brain cells causing subtle effects such as depression, memory loss, and insomnia. Although not provided on the internet website, the actual magazine depicts a brain image of a ecstasy user and another brain image of a normal non-ecstasy user (control group). What actually triggers behaviors such as depression, etc?
These statements caught my attention: "How do we know what's what?"--Kate; "Our 'unique' likes and dislikes sometimes aren't spontaneous; they're the result of inputs that other people react in similar ways to."--Dena; "When we feel sick it is sometimes a state of mind."--Alexis.
In addition, the ecstasy article stated that "look-alike" or fake ecstasy pills are being taken; however, people claim to be experiencing the same effects without even knowing that the pills are not the "real stuff." Can a placebo cause the same effects as the actual substance? Or maybe because society claims certain results, we react unknowingly in favor for these inputs... Or maybe it is a state of mind; maybe it's not the drug, but the thought of what the drug can do that enables certain behaviors to occur... Just wanted to share some thoughts with y'all.
Subject: corollary discharge
Date: Mon Mar 5 20:06:45 EST 2001
Somebody asked why we need the internal control of corollary discharge, why external input is not sufficient. While I, of course, am not in any position to answer this question, it did get me thinking. Without this internal control, would we all be, and think, the same? Do these efferent copies follow different paths in different people? In other words, are corollary discharges one of the places where individual experiences and genetic predispositions act? If corollary discharge is not restricted to motor activity and works in all realms of perception, then does this mean it can account for, at least partially, individual variability in thinking patterns and/or personality?
And the fact remains that there indeed are many different but equally correct ways of looking at things. Many different people, for instance, may agree upon the nature of an object they are all viewing but may deem different characteristics of the same focal point as most attention-grabbing. Just like this forum. Many of us choose to write about the same topic, but take different perspectives and mix the common concept around with different "corollary discharges" to express our own unique coordination of internal signals, or give it our own original twist.
In additon, maybe corollary discharge is a possible "something else that is narrower [than free will], yet still accounts for the variety of human behavior found in all people" that Matt talked about. The concept of corollary discharge is still a little fuzzy to me when we move beyond swimerettes, but it does appear to play a crucial role in the enormous task of juggling our many different inputs and awarenesses in a way that integrates our "selves," internal environments, and external environments into a coherent experience.
Name: Nirupama Kumar
Subject: The Motor Symphony Considered
Date: Mon Mar 5 20:41:17 EST 2001
I really love using the term motor symphony to describe the interplay between neurons. It prefectly describes the delibarated coordination of the nervous system as I see it. All of the neurons working in harmony, according to set composition, but with a certain amount of human flexibility to account for the feeling of the 'music', or synapses.
The idea of corollary discharge makes this concept of a symphony even more interesting because neurons directly influence one and another. It makes sense that neurons coordinate with each other to synchronize basic motor activity, but I do not think I ever considered that individual neurons communicate with each other, without a separate conductor . . . that the lines in the box can really go in any direction--including side-to-side and backwards. The central pattern generators which cause the motor neurons to send out signals to adjacent ganglia along with output signals are created through learning and genetically-determined circuitry.
Genetics, though, determines the basic circuitry of most CPGs. Thus, we see that our inputs and behavior are in a large part due to internal factors which determine how we interpret and share signals. Though we may all exist in a similar environment, our reactions to it vary greatly because of the minor differences among us which determine our neuronal circuitry. I came across the same idea in class and in my webpaper, that no one can have the same experiences because everyone perceives it differently. In researching about synesthesia I learned that the hippocampus influences the sensory perception of all of us, by determining what input is significant over others. These ideas of perception certainly questions how objective we can be about perceiving reality. It would be interesting to see to what extent exactly our own genetics effects our perception of reality.
Subject: pre-programmed behaviors
Date: Mon Mar 5 20:57:15 EST 2001
I find the concept of preprogrammed behaviors very interesting. We've been talking about this a little in my Primate class as well, and we learned that while cats will pounce regardless of whether they've ever seen another cat, they can't kill by the same process (i.e. without having learned from another cat, or by trial and error). So my question is, what is it that determines what behaviors will be preprogrammed for each species? By what evolutionary process were these strains isolated and chosen for preprogramming? It would make sense for me if these were the skills needed for basic survival. But if a cat is preprogrammed to pounce and not to kill then this cannot be the case. Animals must kill and eat their prey in order to survive, right? I suppose once an animal has been caught, the killing would be an obvious step that may occure to a cat, whereas catching by pouncing rather than chasing or anything else may not be come upon if it were not programmed in.
So maybe preprogrammed behaviors are those that are the first in a series of actions needed for a particular aspect survival. Or perhaps they are all locomotor skills seing as how the other example we discussed was flight in birds. I don't know. If anyone has any ideas, let me know.
Name: Christine Farrenkopf
Subject: genetics and experience
Date: Mon Mar 5 21:00:07 EST 2001
I was very interested in our discussion as to whether certain behaviors in the young are innate (such as flying in birds, walking in children, and singing in crickets). I did some reading into bird song and found, as we mentioned in class, that both genetics and experience play a role in learning.
The brains of birds are wired to learn the song of their species, but that song must be heard in order to actually learn it. For example, if a bird hears the song of its species in addition to the songs of other species, it will reject the other songs and learn that of its species. If a bird does not hear any song during its infancy (if kept in isolation), it will sing a "generic" song that is not as complex as that of a normal song. This demonstrates that there is a central pattern generator, but that this CPG can somehow be altered through experience (ie, hearing the song of one's species).
Another concept I found interesting is that of the "critical period" wherein the neuronal pathway of a song must be established within a certain time period in infancy. If a song is presented after the critical period, the bird has a very difficult time learning it. This has a correlate in humans in that it is more difficult for people to learn a second language after puberty. For some reason, neuronal pathways lose plasticity. (Why is this?) Perhaps there is some truth to the cliché "you can't teach an old dog new tricks."
Name: Elizabeth Gilbert
Subject: language response
Date: Mon Mar 5 21:07:57 EST 2001
In response to Claire and Daniel, children do in fact learn langauge at a rate faster than you or I can imagine. In fact people have the potential to learn langauge fluently until they hit puberty. Although with intense study adults can learn a language also it is found that children seem to do it effortlessly. (Hence, many people argue that we should teach second langauges in elementary school when people have an easier time learning a second langauge.) For example, at the University of Rochester, there was a case study of Simon. He was a deaf boy born to parents who were also deaf but they only learned sign langauge (ASL) after puberty. Simon was taught ASL from birth. By the age of 6, Simon was better at the language than either of his parents. He was fluent while they were able to use it but not nearly as compentantly even though they had learned the language long before him.
There are many stories of abused children that have no form of language input but when found before puberty are able to learn language with little trouble. On the other hand there is a famous case of a girl who was found locked in an attic at the age of 12 and although she tried very hard to learn English she never was able to speak fluently. I believe that she never learned to use the correct syntax in her sentences.
So what is it that allows children to learn langauge at such a vast rate? Researchers say it is that children's brains have neural plasticity, that is the abilty to make connections and remove those that are not needed. Thus, a child who suffers a brain trauma in the left hemisphere where language is located for most people will be able to speak and understand again. However an adult with that same leison would not be able to recover as much langauge function. If you are interested in language and how it fits into the nervous system I suggest reading books by Steven Pinker. He is a cognitive scientist at MIT who has written books on this stuff that is meant for laymen. They are very readable and really explain how language is thought to work.
I believe that langauge is a form of central pattern generation. It is found that babies in their initial babbling stages (ie before age 6 months) bable in all phonemes of all languages of the world. However, as they recieve more input from thier caregivers who talk to them, they begin to babble in only the phonemes of their caregiver's language. So the human brain has the ability to learn any language. It is through the fine tuning of listening and copying the caregiver that a baby begins to learn the language that he/she is exposed to. Also, deaf children of parents that don't know sign langauge make up thier own language of gestures. While it is not as complex with all the syntax of something like ASL, it certainly has the rudements of langauge. One can clearly say that these children do not have any language input but they seem to make up language on their own. Also, recent research in Nicaragua has watched the development of a totally new langauge, Nicaraguan Sign Langauge. NSL is a new language about 20 years old. It is a result of the deaf community of Nicaragua coming together and putting all their own gestures into a codified language. It came out of this community wanting to communicate. All of these people had created their own gestures at home with the hearing population around them. When they finally came together as a community, they deaf people created a syntax and official signs over many years. So I think that there is something of a central pattern generation in language. I think it is one of the key central pattern generators.
Name: Elizabeth Gilbert
Date: Mon Mar 5 21:11:06 EST 2001
I know that I just wrote a whole long comment but here is one more. If you are looking for the book by Steven Pinker on language it is called "The Language Instinct". Also of course anything by Noam Chomsky, the great linguist.
Ok, I swear that is it for me this week.
Date: Mon Mar 5 21:18:29 EST 2001
I understand that corollary discharge signals will affect incoming sensory information and that this is what gives each of us unique feelings and perceptions. These signals must affect all animals, but to what extent? Do humans have more corollary discharge signals than wild animals? How much do animals hunting in the wild rely on stored patterns? Do they inherit the way to kill their prey for food or do they do it because of the environment in which they live? I guess this is just another way of looking at the nature versus nurture debate.
Additionally, it is fascinating to consider a simple action as a complex motor symphony consisting of a wealth of complementary parts that fit together so perfectly. Phantom limbs are caused by misshaps that don't affect the circuitry inside the nervous system. What other instances cause misshaps in the interior workings of the nervous system?
What kind of actions are actually acquired? How large a part do the environment and experience play? It seems to me now that a large number of motor symphonies are always present and don't require any outside inputs. It seems like almost everything humans need is coded for in our unique genetic information.
Name: Irma Iskandar
Subject: Phantom Limbs and Such
Date: Tue Mar 6 00:15:02 EST 2001
I found this week's discussion topics very interesting, especially concerning the relationship between phantom limbs and coronary discharge signals, as well as a central pattern system. The implication that people have pre-written motor symphonies is intriguing and yet worries me back to that old concern - that all that constitutes us is merely due to organic causes. It seems creepy in a way, that we could have our motor neurons programmed already, but I suppose I shouldn't be too surprised - once we think about it, our whole body, all of organs, are pre-programmed to move, pump, function in a predestined way.
I'm still very confused regarding phantom limbs though, although it is a fascinating topic. How can we still feel it has been due to the motor circuitry and corollary discharge signals that move the arm and makes one still feel the arm. Before we could have such knowledge, it would be amazing to see how doctors and other people would have reacted to people complaining of phantom limbs. The source of the corollary discharge signals, etc. though still eludes me, I feel we should have captured it in more detail during class. Nevertheless, the topic made me wonder how important the overall coordination of the body results from communication between boxes in the nervous system. I can see how this course is evolving into Grobstein's main belief that brain = behavior. Scary.
Name: Megan Mendillo
Date: Tue Mar 6 00:16:35 EST 2001
In my Psychopharmacology class, we've recently been learning about addiction, withdrawal, tolerance and drug relapse. An interesting concept came up that I wasn't really aware of: environmental or context conditioning can be a direct cause of drug withdrawal, relapse, tolerance, and even overdose. I knew, of course, that when a former addict goes back to the environment where he had originally gotten drugs or had used drugs, the chances of relapse increase. But I didn't know that these effects have actually been replicated in animal models. A few examples may clarify...
It has happened that former addicts who have been completely rehabilitated/detoxified go back to their old environment and suddenly begin to experience biological symptoms of withdrawal.
Tolerance occurs as a drug is taken often and the person must take higher and higher doses in order to get the same effects. A fact related to this that surprised me was that some drug overdoses occur as a result of a person taking a drug at a high dose which they have taken many times before (i.e. a dose which may their body has adjusted to), but this time in a different environment or situation than usual. In that environment, the drug actually causes an overdose, whereas in the usual context the drug would not have had that effect.
This idea has also been supported by research. (I haven't gotten a chance to actually look up these studies just yet, but this is one example from class.) For example, in one study, animals were divided into two groups (A and B) in two different living spaces, and were given morphine for a certain period of time. Then, some animals were moved from the B area into the A area (so that a few animals were in a different context than they had usually received the drug). All of the animals were given a high dose of morphine (LD-50, a dose usually causing 50% of the animals to die). They found that significantly more of the formerly B animals died. Was it a result of being in a different context?
Although not all tolerance, withdrawal and relapse can be accounted for by conditioning, it is definitely an interesting area of research... and could have important implications for the treatment of addiction. It does seem to shed some light on (or maybe just complicate things) the amount of control/influence our minds have over our bodies...
Name: ingrid solano
Date: Tue Mar 6 00:37:00 EST 2001
I was just in my Developmental Psychopathology class today. And we were talking about neurotransmitters and how they discover how they work by basically thinking backwards and trying to be 'a little less wrong'. It was in this class today that I realized how huge of a task behavioral neurobiology really is.
It's not like we can look into the brain and choose a spot (where we don't even know what the function is) and decide how dopamine issues cause schizophrenia, or how seretonin issues cause OCD and Depression.
We were talking about how the seretonin issue in OCD is discovered and uncovered by finding the levels of seretonin metabolites in the spinal collumn, and how those change with drug treatment. We basically have to find the answers 5 or 6 degrees away from the actual answer. We have to assume (by probability) that these chemicals, that effect seretonin, since they're in different quantities in diagnosed individuals, might lead us to a seretonin based hypothesis. Though, where does it work? what exactly is the cause? There are only so many neurotransmitters (that we know of) and yet we can attribute them to multiple problems. And yet we barely have the knowledge to look at where they go and where they work. We have to keep moving closer and closer to the problem through details we notice that may be far away from the answer. This is extremely hard. I think I was a little daunted. But fascinated as well. These chemicals are incredible. We barely have the means to understand them. And if drugs that effect them effect these disorders (which are obviously behaviors)...well... I'm more willing to look under the microscope than in an ancient text.
Name: Paula Green
Date: Tue Mar 6 00:47:38 EST 2001
I would like to comment on the web projects we had due this past week. It was interesting to read what people have found and summed up for the general audience. I cannot predict the future, but if it wasn’t for this course I couldn’t have seen myself ever posting something to be read on the web. It’s just not my style. Just this experience alone says a lot to me and for the people who will read my work and others in the course.
Name: Gwen Slaughter
Date: Tue Mar 6 01:11:03 EST 2001
I too am perplexed by the same things Kate, Avis and Caroline mentioned in their postings. The more I learn about brain function the more impossible it seems that the box-to-box model is responsible for all complex behavior. Like Kate said, pleasurable behavior activates the neurotransmitter dopamine, but centrally mediated pain pathways also activate dopamine. How can a few neurotransmitters be responsible or play a role in so many distinct and different behaviors? Is it the neurotransmitters that make the behaviors different or is the connections between the neurons or is it something else entirely?
Subject: thoughts on language
Date: Tue Mar 6 01:18:40 EST 2001
After reading the comments in the forum about language and how it is acquired, I started to think about the implications of language and thought. It seems we have established that talking is a learned behavior, although children have a much easier time "learning" to talk than adults do. What happens to people that don't learn to talk? What form do their thoughts take? I remember reading a book by Oliver Sacks a while ago that talked about this. Sacks wrote about a deaf boy who never learned sign language. The boy seemed unable to use his imagination or enter any kind of abstract realm of thought. Apparently people who do not develop speech pathways as a child are less likely to develop the types of thought processes older people are capable of. Also, there must be a very significant difference between gesturing with no formal rules (as opposed to sign language) and language with established syntax and grammar, assuming the latter lends itself to so called higher thinking and the former lends itself to more literal thinking.
Name: karen munoz
Subject: dreams and efferent copies
Date: Tue Mar 6 02:19:40 EST 2001
so i was thinking about efferent copies and the little experiment we did in class about poking yourself in the eye and the world appearing to move and how that was different than when we just moved our eyes around from one corner of the room to another corner. and it got me thinking about our sensory perceptions in our dreams--what it appears as though we see--and its correlation to efferent copies. i did a yahoo search about their relationship to dreams and i came upon this web page, which is kind of poorly written, but seems to get the basic idea across nonetheless: New Scientist Planet Science. (http://www.newscientist.com/nsplus/insight/big3/conscious/day2b.html)
basically, it says that when we dream, our brain's attempt to make some sense out of the information it is receiving from the brainstem, and the motor cortex therefore sends out signals for movement. because of sleep paralysis, these movements are not carried out, but the efferent copies are still sent out. therefore, the efferent copy is received by the brain, there is no movement, so the illusion of movement is still created.
this reminded me of our conversation about the phantom limbs and how these limbs appeared to be present and in pain, although they had either never existed, or had been removed. however, the phantom limbs felt as though they were in pain because the movement was not being carried out and the brains respose was to interpret this as something wrong and therefore "painful." why is it that our brains do not interpret these dream efferent copies as pain? it seems as though maybe there is something i am not understanding in the mechanism of efferent copies . . .
Name: melissa hoegler
Subject: something different
Date: Tue Mar 6 02:37:07 EST 2001
I just read something that reminded me of class today. It appears in February’s Utne Reader It is the antithesis to the idea that brain equals behavior. The article is an interview with Biologist Rupert Sheldrake. He believes that all living beings act as they do because of nature’s invisible fields (called morphic fields) that have a sort of memory. For example, a rabbit looks and acts as it does, not because of genes, but because of the memory of rabbitness that is present in it’s morphic field. The study of these fields is called morphology. Sheldrake thinks that genes “tune in” to a certain morphic field. The rabbit, for instance, would be tuned in to the rabbit channel. It all a sounds like a bunch of b.s., huh? But, it is a metaphysical look at something other than the idea that brain = behavior. It also is a really logical explanation for things such as ESP and reincarnation.
Here are some links to learn more about morphic fields if you’re so intrigued:
Sheldrake's Home Page
A quick, scientific look at morphic fileds.
Some more stuff on morphic fields. This one even uses "boxes"
Subject: just some thoughts on language
Date: Tue Mar 6 09:10:39 EST 2001
I thought it was interesting to learn that many think of language as a form of central pattern generalization. I never quite thought about it in that manner. The idea that children learn languages faster because their brains have neural plasticity never occured to me. Before taking this class I generally thought that the environment and social structure were the reason why children learned language faster than adults. When I think of families that newly immigrated to America and my neighborhood I have noticed that the childrens learn english way quicker than their parents. I though it was because they are in school and they tend to socialize more. However, I can see how neural plasticity has its hand in the matter.
Date: Tue Mar 6 09:30:29 EST 2001
The story of Ian Waterman(www.apa.org/monitor/jun98/touch.html) (I haven't mastered html yet)brings up some interesting questions to me. He is the guy who lost his ability to make automatic movements because of viral damage to his 6th sense, proprioception. His "I" function and visual percreption were able to take over where his non "I" function sensory neurons called proprioceptors failed. Only by watching his limbs can he can make movements like walking and reaching and such.
The interesting observation about his behavior is that he makes gestures while speaking quite automatically and normally, compared to his calculated steps that he controls cognitively using visual feedback. His hand gestures related to his speech can be consciously or non-consciously executed. Sounds to me like motor symphonies coordinated by corollary discharge that evolved with speech. The skill of speech probably involved with the communicative gestures of the hands. But is it an unconscious habit due to corollary discharge. What are habits? And why do some people have this hand gesturing more than others if they are part of evolution? These neurons of automatic hand gesturing and speech seem to be an example of neurons that are genetically hooked up in certain ways to form a central pattern generation. Instead of the alternating movement circuit that we discussed in class, it sounds like a coordinated movement circuit.
Also, the ability of this hand gesturing/speech movement to be conscious or unconsciouly controlled is intriguing. Does this mean that the "I" function can interplay with our automatic behavior? For example, can we as some people claim, interplay consciously with our immune system to make our cells get rid of cancer?
Name: Caitlin Costello
Date: Tue Mar 6 21:09:02 EST 2001
Elizabeth mentioned the period of plasticity in language learning, which according to my Psych of Language class this semester is until about 5-7 years. The case of the 12 year old locked in the attic all her childhood was, I believe, Genie (sp?). When she started to learn language as an adolescent, at first people thought she was retarded; however, in contrast to most retarded individuals, who exhibit speech with low vocabulary and high syntax, Genie had advanced vocabulary and very low syntax. I'm wondering what this all means for central pattern generation. You could make sense of it just as a difference in damage to the brain (Genie's left hemisphere having atrophied as a result of so many years without language vs. whatever specific changes occur in other people with brain damages that lead to language difficulty) resulting in different effects on language. But this shift of focus and mastery between syntax and vocab seems like more than an input/output kind of thing; a whole different way of using language, indeed of looking at and understanding the world...it seems to make the CPG notion more complicated somehow, and if language is essential to who we are, throws the whole I-function thing back into this all.
And a general thought on the direction of this class and how we've been delving into the workings of the brain...as long as I'm throwing stuff in from my other classes, I just finished a book called The Differentiated Classroom for an education class. In a differentiated classroom (one that acknowledges and addresses the differences in how each student learns), one thing the teacher must be aware of is that some learn best from a part-to-whole approach, and some from a whole-to-part approach. What we've been doing here with the brain is whole-to-part, which makes sense in that we all know we've got a brain, which is a good reference for then looking closer and closer at the smaller parts of it. But maybe it would be useful to then look at it backwards--once we've got all these parts (the little boxes and such), can we work in the other direction and try to make sense of the whole (the brain) from the parts we now have? Just a thought that might be interesting to try...
Date: Thu Mar 8 01:06:35 EST 2001
Contrary to what I once thought, scientific progress did not consist simply in observing, in accurately formulating experimental facts and drawing up a theory from them. It began with the invention of a possible world, or a fragment thereof, which was then compared by experimentation with the real world. And it was this constant dialogue between imagination and experiment that allowed one to form an increasingly fine-grained conception of what is called reality.
François Jacob, French molecular biologist 1988
Distinguishing reality in neurobio is a daunting task. We have a series of semi-autonomous actors in the brain, nerves, and muscles, which we redefine in every class. To understand the reality of the nervous system we have to realize that all the factors work together in a complicated interplay. And that it has some capacity for spontaneous action, versus some capacity for being told what to do by some upstream/outside constituent. Perhaps I become lost in the concepts but I feel in ideas, we are always dealing with a string of words or more elaborate concepts. How do we compare strings? How do masses of nerve cells interact to shape up new concepts from random noise? How do a group of nerve cells get together to initiate a movement? I think these are the questions that are taking a gradual development and ultimately, a better understanding of the nervous system.
Name: Nazia Ahmed
Date: Thu Mar 8 01:08:16 EST 2001
sorry the last comments were from me. I forgot to type in a name.
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