Biology 202
Neurobiology and Behavior
Spring 2004

Forum 9


Name:  Katina Krasnec
Username:  kkrasnec@brynmawr.edu
Subject:  the brain...
Date:  2004-03-16 09:41:32
Message Id:  8828
Comments:
Over break, I managed to stumble my way to New York City, and on my way there, I picked up a book a professor had given me to read. The basic topic was a girl with epilepsy, who, at a certain age underwent a brain surgery procedure seperate the two lobes of her brain, thus enabling the non-"diseased" portion of her brain to function without the damaged region contaiminating it. However, even after her surgery and the loss of seizures, she still exhibited many of the signs of childhood epilepsy, primarily the inability to comprehend truth, despite this completely evasive and effective procedure. What are possibly psychological reactions/side affects to brain surgery or other extensive medical procedures? Does it change brain function and ability?

Also, as a right-handed person, I'm also pleasantly surprised when I meet a left handed person. From my experiences, they seem to have completely different processes of comprehension than those who are right handed. I know this occurs because each side of the body is connection to an opposite lobe, but what are the differents within these lobes that explain why left and right handed people think and act differently?

Lastly, did you notice we have people out of Bryn Mawr/Haverford commenting? Impressive, I think we're asking the right questions.


Name:  
Username:  aejelonu@brynmawr.edu
Subject:  We're playing basketball
Date:  2004-03-16 10:00:33
Message Id:  8829
Comments:
When I am on the court playing basketball, I have a natural sense of knowing when I was going to get the ball and a developed sense of knowing what I am going to do with it. But on days that my game is off, both senses are off and I feel that it is not me in my body. As if my mind and body is disconnected. I guess that I have to practice more to not allow myself to feel and act differently but I can not help it especially if I am nervous.
Name:  Dana Bakalar
Username:  dbakalar@brynmawr.edu
Subject:  
Date:  2004-03-17 12:44:29
Message Id:  8852
Comments:
"I don't think that children really learn foreign languages better than adults. Rather, I think that their environment makes it easier for them. I think that if adults trying to learn languages had the same privileges as children (a.k.a. not having to worry about feeding themselves, etc.), did not have a family or obligations and could devote all their time and energy to studying the language, the results would be pretty much the same. I don't know if there were any studies done on this, though"

Actually, you are wrong. Chiildren learn language implicitly, without working on it, and with many other responsibilities, such as learning social skills, interacting with peers and family, etc. And studies have been done, showing that children learn language MUCH better than adults, to the point where "responsibilities" couldnt be what is causing the difference.


Name:  Nicole
Username:  nwood@brynmawr.edu
Subject:  Some thoughts...
Date:  2004-03-17 18:49:51
Message Id:  8862
Comments:
As we were discussing Teret's syndrome in class on Tuesday, I wondered to what extent those who suffer from this disorder lack control. Although I do not claim to understand the complexity of this disorder, it seems like it is quite drastic to say that "they" (meaning their I-Boxes) are unable to control their actions. Does this mean that their I-Box is somehow defective, as it cannot control the actions of the the rest of their body or actions. And, if their I-boxes are not in control, what is? What is compelling those with Teret's to do or to say what they themselves do not desire?
Name:  debbie
Username:  dyi@brynmawr.edu
Subject:  
Date:  2004-03-17 19:22:12
Message Id:  8863
Comments:
On the topic of memory and the film Memento, my boyfriend has HORRIBLE memory. He has trouble remembering basic things like birthdays, scheduled events, and people's names. It is frustrating to me because he is incredibly intelligent. He says that he would like to learn to have better memory. Is it possible to obtain better memory naturally without the use of acronyms, rhymes, and mnemonics?
Name:  Mariya Simakova
Username:  msimakov@brynmawr.edu
Subject:  Children and language
Date:  2004-03-17 23:13:34
Message Id:  8867
Comments:
"Chiildren learn language implicitly, without working on it, and with many other responsibilities, such as learning social skills, interacting with peers and family, etc. And studies have been done, showing that children learn language MUCH better than adults, to the point where "responsibilities" couldnt be what is causing the difference."

In an attempt to get it less wrong, I searched online about children and adult second language acquisition, and here's what I found:

http://www.ntlf.com/html/lib/bib/87-9dig.htm

http://www.ericfacility.net/databases/ERIC_Digests/ed350885.html

These summaries suggest not only that adults and children have same potential for learning foreign languages, but that adults actually have an advantage. Of course, these summaries are in no way conclusive or exhaustive (I think I see a web paper topic emerging here :) ), but I just wanted to quickly check if my gut feeling (and I'm a non-native English speaker myself) is shared by anyone else. Again, I'm not saying that this HAS to be true, but my own experience and the experience of people I know suggests that learning potential (and that goes for languages) does not decrease, but increases with age. Now, I admit that saying that a child has fewer responsibilities was not the most convincing way to account for this. But I think that if one looks at it in terms of developmental growth (both conceptual and structural), it makes a lot of sense. But I'll keep working on this :). That's why I like this forum, it makes us all think more (and learn more).


Name:  Mariya
Username:  msimakov@brynmawr.edu
Subject:  Motor symphony
Date:  2004-03-17 23:53:49
Message Id:  8870
Comments:
The more I think about motor symphony and central pattern generation, the more it reminds me of a jazz piece (and NS of a jazz band). In a jazz band, there is no conductor -- the members work with each other and change their music (improvise) both as a reaction to their own thoughts and feelings and as a response to the changes in their partner's playing (and it's actually quite an enjoyable experience for them, they smile the entire time they are on stage). So this fits with the "coordinated performance of independent players" concept. Also, jazz musicians have a score, but they are not tied to it. What makes jazz fun is improvisation on that score, and this improvisation arises both from within the musician (equivalent of potentials arising within the box) and as a result of input from other members of the band (same as NS adjusting our movements on the basis of sensory and other input). If the band (the organism - in biological terms) is well coordinated and has good communication between its members, even the most elaborate improvisation, which deviates from the score quite a bit, is beautiful and coherent. When communication breaks, the music par excellence ends (like the normal functioning of the organism, when the connections within it and between it and the outside world are in some ways severed)...So I think this works nicely...ok, I just wanted to throw it out there, maybe someone will think it useful, but it's also 12 am, so don't look for anything profound or new in this :)...
Name:  Shirley
Username:  sramirez@haverford.edu
Subject:  
Date:  2004-03-18 12:57:01
Message Id:  8876
Comments:
I thought it was interesting the discussion we had on how we remember who we are. Unlike the guy from memento we dont write down who we are then look back at it just to remember who we are. Maybe in a way we do write things down unconsciously somewhere in the brain, but how would that explain how we know who we are constantly. Is there a region in the brain that is resposible for recognizing who we are constantly?

On another topic, i dont think it is dangereous to learn about our own brains. In what way do people think it is dangerous? It is important to learn about our brains to better understand human behavior.


Name:  Dana Bakalar
Username:  dbakalar@brynmawr.edu
Subject:  
Date:  2004-03-18 23:59:38
Message Id:  8881
Comments:
I can see a level of discomfort that could come from learning about the brain. it discounts superstitions that people hold dear, it questions how much concious control we have of our own behavior, and it questions the nature of reality and our perceptions of it. In that sense, it could be damaging to people's worldviews, and as such be seen as a danger. however, i would equate that to things like new knowledge about geology and such proving that the world is very old and has evidence of extinct species, evolution, etc. This challengd the prevailing religious view at the time, and so was dangerous to that way of seeing the world. It was not however, dangerous to the world or to individuals, but rather enlightening. Sometimes we have to do scary things and learn scary realities to develop.

And about language- I didn't know that studies had shown adults as as capable (or more so) of learning language. that is a good webpaper idea, i thought the opposite, and all I've read before thought so too. Maybe there's hope yet for me to learn a language really well!


Name:  Eleni
Username:  ekardara@brynmawr.edu
Subject:  Learning
Date:  2004-03-19 20:10:37
Message Id:  8906
Comments:
On Tuesday we talked about learning something that gets into your nervous system as opposed to learning something that just gets into your I-fxn. I was under the impression that learning through physical actions is the one that gets into the nervous system and is the one you don't forget, i.e. riding a bike. Memorizing in words is the one that just goes into your I-fxn, and can be easily forgotten, i.e. memorizing names and dates of explorers in 4th grade history or memorizing the multiplication tables. At this point in time, I still know my multiplication tables because I use them on a regular basis in daily life whereas I have forgotten the explorers/dates. So if you use the information in your I-fxn regularly, you don't forget it. I think this is where it differs with learning something in your nervous system-you don't have to do the activity regularly for your nervous system to remeber how to do it. For example, I have not gone bike riding in over a year but if I got on a bike right now, I would be able to ride it. Whereas if I didn't use my multiplication tables for a year, I think I would be pretty rusty when I tried to use them. It's like it takes more repetition to keep words in your I-fxn than activities in your nervous system.
Name:  Liz
Username:  epowell@brynmawr.edu
Subject:  phantom limbs
Date:  2004-03-20 15:30:05
Message Id:  8912
Comments:
The idea that the brain is at least partly hardwired for limbs is interesting and I wanted to explore this idea more outside of class. According to this theory, as was discussed in class, if a finger is amputated, the area of the brain corresponding to the finger would not be stimulated. Other corresponding parts of the body represented in the brain may then be able to expand into the area of the finger. Conclusions drawn from this would include that applying pressure to other parts of the body could illicit a response in the phantom limb. This is known as remapping and more can be read about here .
Name:  Emily Hayes-Rowan
Username:  ehayesro@brynmawr.edu
Subject:  Rewiring and Experience
Date:  2004-03-20 19:23:48
Message Id:  8914
Comments:
In his book The Mind and the Brain: Neuroplasticity and the Power of Mental Force, Jeffery M. Schwartz, MD, discusses rewiring experiments done in baby ferretts. Because auditory and visual pathways are not laid down in ferretts until after birth, researcheres were able to lesion the normal pathway from the auditory nerve to the "auditory" cortex. Lacking in auditory signals, what should have been the auditory cortex took input from the visual system. So "the animals 'see' with what was their auditory cortex...[I]n these rewired animals, the experience of sight appears to arise from visual inputs to the auditory cortex." In light of what we have learned, this isn't all that astonishing. However, what I wonder is this: Do the rewired ferretts experience sight differently than normal ferretts? There is nothing special about a visual signal versus an auditory one. So the auditory cortex is getting the same type of input it would have gotten if it were wired to the auditory system. Also, it used to be thought that how a signal was processed depended upon where in the brain the processing occured. (Schwartz says this used to be the case, but doesn't say what the current theory is, which really bugs me.)

So: Are the rewired ferretts "hearing" light rather than "seeing" with their auditory cortexes? Or are these the same thing? Is this what happens in the brains of people for whom sound has color or words have taste? We probably won't ever know how the rewired ferretts experience light, because 1) input does not equal experience, so we can't make any assumptions, and 2) the ferretts can't tell us what they experience. But even if we could do something like this in humans (ignoring, for the moment, the ethics of such an experiment) would the subject be able to tell us about his experience? He wouldn't know anything different, so how would he put it in terms we would understand? It would be like trying to describe color to someone who is congenetically blind. So we would have no way of knowing if he "saw" as we do, or if his "visual" world were a myriad of sound instead. And this, this not being able to know, is just as fascinating as the rewiring.


Name:  
Username:  ehayesro@brynmawr.edu
Subject:  Correction
Date:  2004-03-20 19:25:25
Message Id:  8915
Comments:
Just fixing a typo: congenetically = congenitally
Name:  Emily Hayes-Rowan
Username:  ehayesro@brynmawr.edu
Subject:  Correction
Date:  2004-03-20 19:25:30
Message Id:  8916
Comments:
Just fixing a typo: congenetically = congenitally
Name:  Anjali
Username:  gvaidya@brynmawr.edu
Subject:  Reality
Date:  2004-03-20 21:11:12
Message Id:  8918
Comments:
I've been thinking about something that Kimberly said- about the danger of "excessive reflection within the brain about the brain." And then I think Jenny said something similar- about how there might be ideas, or facts about the nature of reality that might be actually detrimental to us if we knew about them. (I'm paraphrasing- that's what I got from what Jenny said, at least. Sorry if I misunderstood!). That reminded me of something a friend of mine told me once, which was kind of similar, when he was trying to explain to me in an email about Schrodinger's Cat. And I couldn't quite remember what he'd said so I went back yesterday to find that email- and it was interesting, so I'll describe here roughly what he said.

Basically, the idea behind Schrodinger's Cat is that reality is dependent on conscious observation. Which has a lot of very interesting and very strange implications about consciousness and reality both. All reality (according to the theory) exists as simple probabilities, until it's been observed- and the act of observation collapses the probability wave and decides which reality is... "real", I suppose. Decides which of the probabilities becomes the actual state of reality. Which can make your head hurt if you think about it too long. I'll give the example that my friend gave me. First you take the actual thought experiment, of Schrodinger's Cat. It's not an actual experiment- it'd be awful if someone actually did this to a cat, but it's just something to think about. You take a cat, and put it in a box. And then you set up conditions so that there's a 50% chance the cat will live, and a 50% chance the cat will die. However, the experimenter won't know whether the cat's alive or dead until she looks into the box. The idea according to this theory, though, is that the cat is neither alive nor dead until someone goes over to the box, looks in, and consciously observes that yes, the cat is alive (or dead). The cat is in both states- the reality in the box is in both states- until it's been observed.

That in itself is a little hard to digest. But then, say you take it one step further. Say that the experimenter herself leaves the room for lunch or whatever, and realized that oh! Someone has to go check on the cat! So she asks someone else to go check on the cat and see if it's alive or dead. However, she herself won't know whether the cat's alive or dead until the person gets back. She won't know what that person has seen. Nobody knows what that person's seen. So that second person also exists in two states until he/she's come back and told the experimenter that the cat is alive or dead.

And another implication of this theory is that if a tree falls in the forest, with no one around, there is no way to know whether it made a sound or not- not just because no one was there to hear it, but also because its reality will exist as probabilities unless someone's there to consciously observe it.

My friend ended his letter with, "This is one of the reasons physicists sometimes end their days in lunatic asylums."


Name:  Erica
Username:  egraham@brynmawr.edu
Subject:  
Date:  2004-03-21 12:52:19
Message Id:  8923
Comments:
This week's postings reminded of something that I saw last semester in a linguistics class. We observed the McGurk effect, which is basically another illustration of how we can perceive a reality different from that which actually is. One person stood in a corner facing a wall, and another stood in front of that person facing the rest of the class. The first person said the syllable "ba" repeatedly while the second, whom the class could see, mouthed various syllables such as "da," "fa," "ba," "ma," and so on, to the same tempo as the first person. The result was that the class actually "heard" the first person, who was repeating the same syllable, say most of the syllables that the class saw being mouthed by the second. This suggests that our perceptions seem to be flawed. I think this experiment is an interesting one because usually people are able to believe things that they personally experience, but if the input we receive and "our" interpretation of it creates a false reality, where does our sense of "real" reality originate?
Name:  maria s-w
Username:  mscottwi
Subject:  
Date:  2004-03-21 16:13:56
Message Id:  8927
Comments:
I don't think it's "dangerous" to learn about the brain. I think that people often feel there is something 'sacred' about the self and emotions and such, so learning the mechanics of it seems 'unnatural' but I think it's a mistake to think that personal discomfort with a topic means that the topic shouldn't be studied.
We've been talking about how practice can make permenant certain actions or reactions (like a tennis serve), but I'm also wondering about how a single formative event can permenantly change the way you react or process certain things. When I was twelve we were robbed in what the police term an "armed home invasion." I woke up in the middle to a man holding a gun in one hand and reaching towards my face (actually, he was going for my pillowcase to put jewlery in, but to me it seemed like my face.) The whole thing went on for ages and was a generally unplesant experience, with the man screaming at my father and shoving my mother around with a gun to her back, yet it's almost eight years later and even now if something wakes me up suddenly or if I'm half asleep and something startles me, I have a HUGE reaction to it. It only lasts a split second, as soon as I realize where I am or what it was that startled me, I'm fine, but that over-the-top default reaction is, I think, a direct result of that experience. It always seemed odd to me that I've woken up thousands of times WITHOUT a man with a gun standing over me, and yet it only had to happen once for my brain/behavior to *really* show the effects of it. I hate that I practically go into cardiac arrest if I bump into someone when going to get a glass of water at 3 am, but I honestly don't think I'll ever be able to be how I was before that expereince, and it makes me wonder why that is, why my mind seems to have permenantly decided to expect or at least be on gaurd against another robbery even though I KNOW that the chances of that happening again are so small as to be insignificant...but logically KNOWING that doesn't seem to make much of a difference in this case...I don't know...it was just something I was wondering, maybe all those psych majors out there have some insights.
Name:  Brad Corr
Username:  bcorr@brynmawr.edu
Subject:  learning by action
Date:  2004-03-21 16:55:35
Message Id:  8929
Comments:
I've been thinking a bit about the process of learning by doing rather than by reading as we discussed the other day. we established that people learn better by different methods. I learn better by actions can remember them quicker. Relating the process of learning to the symphony mechanisms we learned the other day I was wondering if the process of learining occurs by actually establishing new neural connections or symphonies? When I finally learned how to ride a bike was it because new neuron connections created the correct symphony so that I know what to do? Or did I simply use old connections and maybe switch from neural excitor's to neural inhibitors in some places? Basically I'm wondering if the specific neural map has the ability to physically change or wether it doesn't need to because learning is simply altering which neurons fire/don't fire? Is there a physical distinction that occurs when something is finally "learned" and I would imagine that this would be different for both short term and long term knowledge.
Name:  Tanya Cooper
Username:  tcooper@brynmawr.edu
Subject:  Memory
Date:  2004-03-21 23:17:29
Message Id:  8931
Comments:
I have especially found the discussion on the human capcity to remember interesting this week, especially the idea of possibly conditioning memory. Something that baffles me is how the human memory responds to trauma and how some people have the ability to block out the memory of painful events. Also, what triggers sudden recollection of the said event? Is it sensory, social, or does it have to do with brain chemistry and the CNS? I was doubtful of the existence of selective memory until I myself recalled a hurtful incident in my childhood that I had managed to suppress for all of my teens and my early adult years. I never gave the situation any thought until something ( I don't know exactly what) triggered my memory. Now, I can replay the situation in my head so vividly that I find it impossible to imagine that for twelve years of my life I never gave it any thought.
Name:  cham
Username:  chamovitz@aol.com
Subject:  more on phantom limbs
Date:  2004-03-21 23:48:12
Message Id:  8933
Comments:
"According to this theory, as was discussed in class, if a finger is amputated, the area of the brain corresponding to the finger would not be stimulated."

actually, the area of the brain corresponding to the amputated body part is still stimulated, even though there has been deafferentation corresponding to that body part and thus a lack of sensory imput. for example, many of the early studies on phantom limbs we performed on monkeys whose limbs and digits were amputated by experimenters. in one ground-breaking study, it was shown that when a monkey's middle finger was amputated, touch stimuli of adjacent digits led to demonstrable stimulation of the cortex corresponding to the amputated digit.

"Other corresponding parts of the body represented in the brain may then be able to expand into the area of the finger.Conclusions drawn from this would include that applying pressure to other parts of the body could illicit a response in the phantom limb"

phantom limb studies have provided evidence that has convincingly demonstrated the plasticity of the adult brain in terms of remapping of the somatosensory cortex. for example, several studies have shown that due to the way in which the somatosensory cortex is organized in primates (i.e.,including humans), when a person has their arm amputated, touch stimulation of their lower face region results in sensations or pain in the missing limb. this is the result of cortical organization, which makes perfect sense when we remember that accordingly to the somatosensory map (commonly known as the homunculus), the area of the cortex corresponding to the face is directly adjacent to the area corresponding to the hand/arm region. interestingly, the receptive fields on the face are both distinct and differentiated in terms of the digit/area of the limb with which they correspond. in other words, in one study of 2 right upper arm amputees, sensory stimulation of particular areas of the face, corresponded to particular digits in the phantom limb (e.g, the pinky finger, the thumb, the middle finger, etc.).


Name:  Kristen
Username:  kcoveles@brynmawr.edu
Subject:  motor symphonies
Date:  2004-03-22 15:00:55
Message Id:  8940
Comments:
I find it interesting that in the motor symphonies there is no overall score or conductor. I have enjoyed the comparison to functions of the body with musical symphonies and when thinking about any good musical group, it makes sense. The best groups of musicians don't need a conductor because not only do they each know their own part so well, but they know how to work and use each other to create the final output. The same makes sense for the boxes of the nervous system. They each know there own set of rules, but they are also quite good at communicating with each other through corollary discharge signals. This concept is quite surprising to me because I had always assumed that there was some kind of controller box that was perhaps located in the brain.
Name:  debbie
Username:  dyi@brynmawr.edu
Subject:  
Date:  2004-03-22 16:49:13
Message Id:  8943
Comments:
I have been thinking about the explanation for phantom limb pains which we discussed in class. The lack of sensory signals due to an amputated limb and the continuing excitation of corollary discharge signals seem to explain the shocks and burning that over 80% of amputees experience. However, this explanation doesn't seem to explain another sensation that most amputees experience -- wetness of the phantom limb.
Name:  Amy Gao
Username:  agao@brynmawr.edu
Subject:  a little bit on memory
Date:  2004-03-22 17:44:21
Message Id:  8945
Comments:
When I was six, I nearly drowned, and from then on I had this extreme fear of large bodies of standing water. My parents' efforts to have me learn swimming ended in total failure, because I would just stand in the water and refuse to have any contact with it from waist-up. I didn't learn to swim until eighth grade. However, when I took my swim test in my freshman year, and when we were instructed to float on our backs I had a panic attack and almost couldn't do it. I had to tell myself repeatedly, "If I can swim, I can definitely float." to keep going. Maybe the event was so traumatizing to me at that time that even though I have learned to swim, my body still reacts to the water the same way when I am in the water and in a position that my body "recalls" back to my nearly-drowning experience.
Name:  Katina Krasnec
Username:  kkrasnec@brynmawr.edu
Subject:  even more on phantom limbs...
Date:  2004-03-22 19:25:06
Message Id:  8947
Comments:
The boards have become such an interesting place to read through. I enjoyed Mariya's explanation of the motor symphony as a jazz band, and it got me to thinking, as with anything in music, it can go out of tune. So, what is to occur if the motor symphony isn't processed or sent out "in tune" so to speak?

Is the sensation that people who are amputee's have similar to that of one's arm falling asleep? What effect does the sight of a limb, or no limb at all have on sensation? I can remember one experience of waking up, and having a prickling sensation in my arm, but as I looked down onto my arm, I had no sense of it being connected to me as a whole. Why would something like this occur?

Certain parts of the body can be stimulated to get reaction for another area/part of the body. In the case of sciatica, the diagnosis is usually given when the patient complains of stinging pains or sensation occuring when moving the shoulder. Could this movement of sensation also relate to phantom limbs, as stimulation in a certain area of the body once connected to the area amputed result the in nerves there producing an electrical stimulus, thereby creating possible sensations of phantom limbs?

As for languages, is there a point where the brain cannot process any more different languages, thus limiting how many we can learn?


Name:  Lindsey
Username:  ldolich@haverford.edu
Subject:  Origin of Language and Imitation
Date:  2004-03-22 20:00:09
Message Id:  8948
Comments:
Going back to the question of language and speech, I thought I would do a little research and came upon a special issue of "Science" Magazine devoted to language and linguistics. The question posed was when or where do we pinpoint the origin of speech (and how does this relate to language?)?

Some theories suggested it came about as a result of natural selection, or the development of certain parts of the brain (Broca's areas and Wernicke's), or the discovery of FOX2P (the "speech gene"). The theory that I found particularly intriguing is that speech is arguably a motor activity rather than an oral exercise. By motor activity we mean the movement and coordination of the face, mouth, larynx, tongue, breath and cognitive activity. Sign Language, or a primitive form of it can be thought of as an "intermediate behavioral manifestation" between animal communication and speech. Clearly, we must redefine what we mean by speech: is it primarily oral or motor? What do we mean by oral and motor? One of the first steps we can take is to look at languages across cultures and see how predominant gestures and facial expressions are in conjunction with the spoken word: can the two be separated?

If we follow the motor theory further...the basal ganglia, which is responsible for movement, acts as a "sequencing engine" that makes the combination of verbal and gestural possible. The concept of imitation came up as one process that enabled the evolution of human speech. By imitating gestures and speech sounds, and incorporating these observations into our own behaviors, what does this suggest about language as an innate ability?

Also, going along with the learning string, would it be horribly provocative to say that imitation and learning are the same thing? Going back to brain=behavior, since the brain contains the ability to imitate (something which is something external from the brain), doesn't this complicate the relationship between brain and behavior?


Name:  erin
Username:  eokazaki@brynmawr.edu
Subject:  
Date:  2004-03-22 20:11:27
Message Id:  8949
Comments:
I thought that our discussion of phantom limbs was really interesting -- in particular the fact that the nervous system still receives information and signals related to the limb even after it has been removed. The fact that it didn't matter if the limb was physically there -- the signal transmission operate upon the basis of the limb's physical existence -- got me thinking about the extent to which our nervous system can "operate" (in varying degrees) without the experience of doing the action. Do we physically have to engage in an action for our nervous system to be aware that we are actually doing something? If the nervous system operates without "seeing" what physically exists, then does our "physical being" really account for reality at all? In the case of phantom limbs, the nervous system seems to have a mind of its own. Are signals firing off randomly all the time, with varying degrees of relevance and application to everyday actions? And if so, how do our inhibitory mechanisms know which to inhibit and which to let fire? In the case of people born without certain limbs, the fact that they still experience phantom sensations leads to the observation that signals are not dependent on the experience of having that limb. To what extend does our nervous system exhibit innate tendencies? For example, if I were born unable to walk, does that mean that my nervous system lacks the ability to perform the motor symphony that corresponds to walking? Or does my nervous system posses the innate ability to conduct this motor symphony even in the absence of the physical experience? If I get a prosthetic limb, will it drive my nervous system crazy, or will it help it out?
Name:  elissa
Username:  eseto@brynmawr.edu
Subject:  Reality and Memory
Date:  2004-03-22 21:33:45
Message Id:  8950
Comments:
There's a new movie out called "Eternal Sunshine of the Spotless Mind", in which one of the main characters has the tumultuous parts of her relationship with her boyfriend removed. If we were able to pinpoint an area in our brain that would completely remove a part of our memory, how would our "new reality" be defined? What if this removal of our memory made us lose a substantially important memory, such as the birth of our child? Would we be living in reality?
Name:  Sarah
Username:  scaldwel@brynmawr.edu
Subject:  Phantom limbs
Date:  2004-03-22 21:49:19
Message Id:  8951
Comments:
I've been looking into this whole phatom limb situation becuase I have been confused as to why there appear to be different degrees of phantom limb "feeling." Why some people describe their missing limb as feeling wet and others describe it as burning? SO, it turns out that the conditions under which the limb was lost determines what time of feeling the phatom limb has. For example, a person who loses their hand while in a fisted position, will continue to feel that hand is in a fist even though there is no hand. Furthermore, depending on the situation in which the limb is severed, a person will feel a burning sensation or not. I think burning results from quick separation of limbs, but you will have to check me on that. I just thought this was very interesting and wanted to share.
Name:  Emma
Username:  eberdan@brynmawr.edu
Subject:  thoughts
Date:  2004-03-22 23:42:14
Message Id:  8954
Comments:
I don't think it is dangerous to use the brain to think about the brain. The brain is so complex and intricate we probably will never understand it but its all we have. Its the only tool we have to look at oursevles and our environment.
To me the brain is like a sand trap. Information goes in and disapears but you never know what you will drag out. Bits of information or memories can stay hidden for years. Because of this we will never be able to fully comprehend the brain using the brain but there is certainly no harm in trying.
Name:  Ginger
Username:  gkkelly@brynmawr.edu
Subject:  
Date:  2004-03-23 00:12:27
Message Id:  8955
Comments:
First, I'd like to say thank you to all those who have been posting about humans perception of "reality"/"is studying the brain dangerous?" It has challenged me to look outside my comfort zone. I appreciate your thoughts. In my post this week, I would like to build on the "reality" discussion. While perusing the course lecture notes, I was able to read an article about "space sickness." Mixed Up in Space The article discussed the ways that astronauts perception changes in the conditions of space. For example, when gravity is gone, up and down is much more of a challenge to delineate. And what you ask causes this predicament? It is the result of the inner ear adjusting to lack of gravity. This article made me really reconsider the hierarchy governs our sense of reality. I often credit my brain with what I perceive. However, in the aforementioned case, it seems that our senses are masters over what makes up reality. When a sense is altered, our perception is as well. If senses=reality, it would explain why it's easier for humans to fathom concrete aspects of life. Is what we know, only what we see?
Name:  Mike "Dr. Doooom" Fichman
Username:  mfichman@haverford
Subject:  motor memory, not always such a big deal
Date:  2004-03-23 00:15:16
Message Id:  8956
Comments:
I was talking to my cousin this weekend. He's a head and neck surgeon, and he says that frequently not only do they reattach damaged axons, but they also graft axons from here to there all across the body (he helped reattach a hand as an intern). I asked him if this had ramifications for motor memory. He said that this 'side effect' is generally overrated. Yes you do have to generate new motor memory, and if it is a fine movement that has taken much practice, it may not come back (playing piano, tying your shoes). But nerves which are grafted into large muscles which do rather unspecialized stuff (walking, driving) that does not require much fine motor skill- it's no biggie.
That kind of blew me away. Here we move from "it's all the same" (neurons as the basic unit) to "it's insanely complex" (think acid flashbacks while having a freudian slip and a phantom limb tingle) and back to this simplicity and universality. The CNS is difficult to manage as a concept because of its complexity despite its homogenaeity (homogeneousness?)- a concept which implies a degree of simplicity and manageability.
Name:  Aiham Korbage
Username:  akorbage@haverford.edu
Subject:  Neurons and learning...
Date:  2004-03-23 00:30:22
Message Id:  8957
Comments:
The topics of Central Pattern Generation and Corollary Discharge, which we have been discussing, are new discoveries for me! They are definitely challenging the way I used to view the Nervous System and the behavior of neurons. It has also been amazing to learn about these complexities that our brain is capable of.

I wanted to add to Brad's comment about neural connections and learning. In the Cognitive section of Intro to Psych, we looked a lot at Memory, Learning and Retrieval. I think that approaching this huge and complicated topic of learning would be of greater significance if done from different disciplinary points of view at the same time (Bio, Neuro, Psych ...etc). For example, in Psych class we talked about the NeuroMuscular Theory, which says that mental practice activites the same patterns of neuro-muscular pathways as the actual physical task. As you know, mental practice has indeed been proven to be effective (and some coaches still use it to train their teams). This is just to give you an idea of how rich and complex the processes associated with learning can be ...

(By the way, I'm a big believer in the Liberal Arts, and that the different sciences or disciplines complement each other).


Name:  Ghazal Zekavat
Username:  gzekavat@brynmawr.edu
Subject:  thoughts on phantom limbs
Date:  2004-03-23 02:25:27
Message Id:  8958
Comments:
I just remembered a thought I had in class on Thursday. If pain occurs in phantom limbs because the brain is realizing that there is something wrong (ie, signals are being generated, but there's no limb there to carry out the action), can someone will an existent limb to feel pain? Obviously you can't make a body part hurt just by thinking about it... instead, suppose you consciously decide not to move an arm for an extended period, then would it be possible to feel the sort of pain experience by people with phantom limbs? I'm fairly certain that the answer here is no. The only reason I bring up this point is that I think it's interesting to think about 1) how much our body is capable of sensing at any given moment (ie, the arm would still sense temperature, it would still have blood circulating in it etc) 2) the effect that the brain has on... everything, as well as how large and important that effect is. Although the experiment I mentioned above (willing an existent limb to feel pain) could most likely never work because it would be next to impossible to eliminate all the factors that may contribute and alter any outcome, it would be interesting to sense what that sort of "nonexistent" pain would feel like first hand, and it would be interesting to compare that pain to pain caused by an actual limb.
Name:  Mridula Shankar
Username:  mshankar@brynmawr.edu
Subject:  pain perception in paraplegic patients
Date:  2004-03-23 03:41:54
Message Id:  8959
Comments:
Somewhere along the lines of phantom limbs... it is interesting that even paraplegic patients who have had a full break in the spinal cord below the neck experience feelings of pain and burning in the lower limbs. Thus a break in the sensory circuit from the periphery to the brain doesn't stop the brain from creating an output (with respect to the these limbs) which is transformed into a conscious perception. This seems to indicate that there are other areas within the brain apart from the somatosensory network which function in parallel leading to perceptions of pain and feeling. Technically the neural network(s) between the brain and limbs are severed so are these feelings of pain real or just imaginary simulations created by the brain?
Name:  Chelsea
Username:  clphilli@brynmawr.edu
Subject:  
Date:  2004-03-23 04:32:39
Message Id:  8960
Comments:
I want to comment on what E(lissa) brought up with "The Eternal Sunshine of the Spotless Mind." Although the film is primarily looking at memory modification, I think it relates really well to things like Christopher Reeves' sense of self and agency, as well as our own individual perceptions of self. If we had a large chunk of our memory removed, would we be a different person? Or would we be the same person, just without the tools to understand why we are? For example, the movie removes the memory of a bad/distressing relationship...but does the character still have a tendency to shy away from relationships of a certain kind? If they met someone similar to the person they'd had removed would they experience emotional responses to them "learned" from the previous relationship, even though they have no memory of it? Basically, things must exist/have wider reaching effects than the isolated locations we put them in (because the boxes are all connected), so wouldn't it be impossible to remove someone from your mind because you still have their impression upon you?
Name:  Michelle
Username:  msamuel@brynmawr.edu
Subject:  DE-learning
Date:  2004-03-23 04:50:43
Message Id:  8961
Comments:
So far everyone has been talking about memory and the process of learning. To me, it seems bizarre that we can smell a certain smell and be taken back to a time when that smell was first experienced or a major part of a certain experience. Our unconscious memory is the bridge that connects us from a known sensation to an unremembered memory. We have taken time to explore memory, but not yet the phenomena of trauma erasing memory. The brain seems to "self-regulate" the mind into erasing physically or emotionally destructive events. This idea of "self-regulation" seems to be a common feature among human brains. It seems odd that these traumatic experiences can range in length from a day to years and the brain still diagnoses and treats accordingly. This being the case what accounts for the ability for the brain evaluate the possible detrimental side effects that could result from a bad experience? Do individual brains have varying "memory pain thresholds?" Perhaps instead of thinking of the process of trauma erasing a bad experience as erasing memory, it should be thought more of as a learned modification of a past-learned experience. The brain teaches itself to disconnect smells, feelings, and sights involved with a bad experience and to eventually connect each component with new memories. How does this process affect the neurological mapping? It seems to me that memory erasure would just be an adjustment in the learned motor symphony attached to specific events.
Name:  Tegan
Username:  ageorges@brynmawr.edu
Subject:  Peripherally Related Philosophy
Date:  2004-03-23 08:00:33
Message Id:  8962
Comments:
In response to a few people's posts (Jenny's and Erica's, mostly..)

What's the point of confirming our experiences of reality to be Real (or convincing ourselves that it isn't, for that matter)? Truth is messy. If truth or reality is individual and subjective—as cases of phantom limbs might suggest, for example—it seems that there is at least some support for no one in particular's concept of reality to be true. Any one of us could have it wrong, and there is no Deus ex Machina, no final arbitrator to tell us who has it right. If one person can have reality wrong, than any/all of us could, too; and where is the usefulness of a concept of a True Reality to which we cannot be sure any of us has access?

Both of the posts I mention appeal—at least in passing—to interpersonal interaction as maybe providing an answer, and I think they may be right. If we think of reality as a learned social norm built over time and not as The Way The World Is, it makes sense to speak of what is real and what is not. People and places and things are real because a lot of people think so; it is how we have come to structure our world and our social understandings of our perceptions. The mentally ill or paraplegic or whoever seems not to be in agreement is out of luck: s/he can define reality as s/he likes, but the majority of us aren't going to go along with it.

If we can understand reality as a constructed narrative, and not as some external entity to be "discovered" with our unreliable and stubborn and easily fooled senses, then we have more leeway in deciding how we understand reality. For example, how do we know what is really real and what is not? Real is what we've all agreed to. What would be the point of deciding our currently understood reality needs to be altered? To fix the narrative to be richer, more useful, etc.

In trading an external reality for a self/socially constructed one, we trade uncertainty for flexibility. In this conception of reality, we can't know that we are right, but who cares? We can't know if we are right thinking of reality as external or fixed either.




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