Name: Katina Krasnec
Subject: Blind spots, the brain, and vision
Date: 2004-04-13 09:06:13
Message Id: 9327
The "exercise" done on Thursday really put a few questions into my own mind about my vision. I'm legally blind if I do not have any "optical aids." When doing the demostration, I had to do it with my glasses, as I generally don't take them off. But, if I would have, would my brain still be able to "recreate" the line despite having the wrong signals sent? Is my blind spot in a different place when I wear my glasses versus when I don't? My eyes have been degenerating very quickly since I was 8 years old, so could my inability at times to see certain visual tricks be attributed to this? I know it would be a simple experiment to do...but I get intense headaches when I try to see without my prescription!
Vision is such a funny thing; but a brief poll. How many people in the class have visual correction aids such as glasses or contacts? What were your perceptions about possible changes in brain response due to the vision deteriorating?
Name: Laura Silvius
Subject: Vision and visual aids
Date: 2004-04-13 15:43:09
Message Id: 9341
I started getting bad eyesight ("going blind" as my family terms it) when I was about eight years old, due mostly to my reading in the dark so much, according to my mother. I didn't get glasses until I was ten, and until that time I would just try to get a seat at the front of the class so I could see the board, and when that no longer worked, I just copied notes from the people next to me. So for ten years now I've been using some sort of vision correction. For a long time, my vision got progressively worse every year, and always by the same interval - from -3.0 to -3.5, the next year from -3.5 to -4.0, and so on. Every year I had thicker glasses, stronger contacts. When I went in for my check-up when I was 17, however, my vision hadn't worsened since the last time I'd been there, but had stayed the same, and a trend which I could previously have absolutely depended on seemed to have disappeared altogether. That was three years ago, and my vision is still the same now as it was when I was a junior in high school (-5.0, in case anyone was curious). What happened to that trend? Why did my vision suddenly plateau like that? I certainly don't do any less reading than when I was in high school. What could possibly account for this sudden change in the pattern?
Name: Laura Silvius
Subject: Re: dreams
Date: 2004-04-13 15:53:05
Message Id: 9342
Last night I had a dream where I saw a poster advertising a concert for Madonna and Tim McGraw. When I woke up this morning, although the other details of the dream had eluded my memory, as soon as a friend mentioned that she wanted to find a concert to go to during finals period, I immediately started wondering if I could get tickets for the Madonna/McGraw concert. It took me a while before I realized that I'd been dreaming, and that such a concert didn't exist. This line between fantasy and reality in one's own head as it relates to dreams and day dreams I think is interesting - where does one end and the other begin? Certainly not between the boundaries of sleep and awake, for how many of us have dreamt of things which have actually happened in our own lives, and how many of us have awakened implicitly believing the things that we dreamt had been real? So where is this line drawn, then?
Subject: on today's class...
Date: 2004-04-13 18:33:48
Message Id: 9344
I got to thinking about today's class, that the brain is "making it up" in respect to our vision. Granted, there are certain rules that we talked about like the lateral inhibition network which works based on the perception of "edges." Looking back to earlier in the course, when we talked about signals starting in the middle of the box, couldn't this be true as well for vision? If a signal could start spontaneously in our eyesight, does this account for hallucinations? When and how are hallucinations induced? Obviously, chemicals play a huge role in this, but I would be interested to know how they interact with our vision process, or are images generated from another part of the brain?
Clearly, hallucinations are based on some form of reality, but they also seem to blend into the dream world, the world of imagined forms. How do signals starting in the box and what we are perceiving as the world relate as visual processes? In some ways, our brain "making things up" can be the overlap of the two, but that doesn't seem quite right according what we discussed in classó our neurons are operating under a genetic set of rules that dictates this perception.
Date: 2004-04-14 15:09:29
Message Id: 9367
In response to Cham's post- I came in late for Tuesday's class, so I don't know if this was discussed already. But I'm sorry, I realized that I left out part of that experiment- with the people sticking their hands in cold water and getting third degree burns. It wasn't just cold water- it was freezing cold water. And if you try it, after a certain point very cold water and very hot water begin to kind of feel the same. In the initial shock, you could believe that freezing cold water was actually very hot water, if you were told to expect hot water.
Granted, freezing cold water still isn't supposed to burn you. Which is where the fact that they were expecting boiling hot water became important- the expectation dictated how their bodies reacted to it.
But, you know what? Now that I think about it, I wonder if this was just a thought experiment, and not a real experiment. I heard about it a long time ago, and I might not've known the difference at the time. I can't think who in their right mind would actually agree to participate in an experiment like this, at least- even if they were getting paid for it. And I just googled it, and nothing's coming up, so there is a definite possibility I'm completely wrong about all this. But still, it's an interesting idea.
Name: Shirley Ramirez
Date: 2004-04-14 22:56:54
Message Id: 9376
What we discussed in class on Tuesday was extremely interesting- I am talking about the fact that our brain seems to "fill in" what is between the edges. It is interesting to note that it does so by relying on our experiences and what it has seen in the past. But its weird to think that what we think we are seeing is not really what we are seeing. It is just so interesting that how we see things is 100% based on what our brain (eyes) has seen before.
I was also wondering how awful it must be for an individual not to be able to see. Most of us perceive our surrounding visually and then interpret what we see. It must be hard to perceive our surroundings without any visual stimulus.
Name: Natalie Merrill
Subject: filling in
Date: 2004-04-16 23:08:39
Message Id: 9406
We have talked a lot about how our brain 'fills in' missing areas in our vision. It got me to thinking about what else we might 'fill in.' Certainly when you consider the vast number of daily assumptions we rely on to run our daily lives, our mind must interpret endless implicit meanings based upon the shared assumptions we all share. When talking to anyone, head nods, facial expressions, body language, they all visually and non-verbally clue us in to information we aren't TOLD or can SEE, rather we must interpret or 'fill in' those meanings. In both cases of visual filling in and shared meaning filling in, our mind relies on a set of understandings established through previous experience and memory. We must be taught to unconsciously interpret our surroundings. What would a stranger see, who had never before encountered Earth or Human behavior before? It makes you wonder...
Date: 2004-04-17 18:13:46
Message Id: 9410
I am still very interested with our conversation on vision. I have never learned this much about optics before! One thing I found interesting was that both of your eyes send two different sets of info to the NS. I had always thought of the eyes as "one," but clearly each eye is a separate entity. It is just that the the NS uses both to come up w/ one story-the best story. I don't have glasses but my vision is not perfect. Ever since I was little, my right eye has been nearsighted and distant objects are blurry. But my left eye does not have this problem, so looking at distant objects with both eyes is clear. It is interesting that the NS rejects the "bad information" from the blurry eye and just uses the info from the clear eye when creating the picture-and thus creates the "best story." On a different note (and this is really basic but it keeps coming up) it is shocking just how fast your NS can process info. I mean, w/ vision alone, it takes the two conflicting stories and puts them into one story with a microscopic time lapse. Plus, add the millions of other fuctions of the NS. It is just amazing...and blows away our concept of time.
Name: Amy Gao
Subject: a little tangent on the subject of sight...
Date: 2004-04-18 12:31:23
Message Id: 9415
Since we are discussing the subject of "being able to see", among other things, I was told once that individuals who are blind/mute/or other physical disabilities have "sharpened" sensitivities in their other functioning senses. For example, a person who is blind may have sharpened hearing than we do to make up for the disability in one part. I'm quite interested as to how this phenomenon occurs.
Subject: Response to Amy's inquiry
Date: 2004-04-18 19:52:18
Message Id: 9421
In response to Amy's posting:
I think the answer to your question goes back to our discussions of "practice makes perfect." When one loses the ability to see, the other senses of the body aren't directly affected. Meaning, if I lose my sight my other senses aren't automatically increased in sensitivity. I looked a little bit online and found that really, the other senses are not heightened, but rather are used more. Because a blind person if forced to rely more heavily on those senses, they become more "sensitive" in that they are more accurate. I don't know if I am explaining this very well, perhaps an example may help: If I am right handed and break my right hand, then I am forced to used my left hand. At first my left hand may not be very useful or accurate for the tasks I need. But over time, my left hand will become more useful and accurate. If you want to look around some more: http://www.rnib.org.uk/xpedio/groups/public/documents/visugate/public_chanfoc.hcsp
Date: 2004-04-18 20:37:06
Message Id: 9423
On "being able to see" and what else we fill in: I am very bad at reading social cues. Basic facial expressions, i can do, but subtle signs of embarrasment, dscomfort, amusement and such are harder, especially if the individual is trying to disguise the reaction. I fell lilke maybe my brain is having trouble filling in the social meanings of these movements, and so it throws out the information, like it throws out tiny details of the scene around us. We remember the general picture but not where each leaf and bird was, and my brain looks at the general picture but not each subtle signal. This causes a lot of problems, because my brain is ignoring information which my I-box would quite like to have, because it would make social situations easier.
Also, about the line, if any, between dreams and waking life: Memories and even the present exists inside your brain, as do dreams. The picture in your head is a representation of reality, but with stuff filled in. Memories are a representation of what used to be in the picture in your head, but garbled, rearranged, and filled in (amd how much of what we remember actually occured? how much did we dream of? how much did we just make up or fill in?) . Dreams are...... a representation of the self?
Subject: Angsty Teenage Depression
Date: 2004-04-18 23:46:40
Message Id: 9426
Regarding dreams, I'm curious about the relationship between dreams and reality. It is assumed that life and what truly happens influences one's dreams. But, does a dream subconsiously influence real life? For example, if in a dream, the dreamer has a fight with her boyfriend and wakes up the next day with no idea of this dream, will her thoughts and actions from then on be influenced? I wonder how this would be studied.
Subject: Magic eye and box models
Date: 2004-04-19 00:13:37
Message Id: 9427
I've been wondering since class on Thursday what Magic Eye drawings/photographs have to do with binocular vision. My vague understanding is that your eyes are tricked into thinking they see separate perspectives of an image, and because you see two perspective the image appears to be in 3D. But how exactly do dots on a page translate into separate perspectives of an image? It's always puzzled me.
One other thing: about what Mike said, "We have examined the inputs, outputs and internal mechanisms of the CNS box, but we are yet to truly address these issues outside of a vacuum, to ask: what is the state of the box in the prescence of other boxes? ... Perhaps we could draw a larger box around a population or sub-population- where messages are sent and received between boxes representing individuals, who are made up of boxes representing neurons etc." - There's just one thing I'd like to say about this. I think that there is a definite limit to the usefulness of boxes-within-boxes models. We could very well put the entire outside environment into little boxes, but what would be the point? How far would that help us, in understanding it? One reason, I think, why such a model is helpful when you're studying the nervous system is that the nervous system has some semblance of order to it- maybe partly because it has specific purposes, specific functions to fulfill. The survival of the organism depends upon that organization, that predictability. But even with the nervous system, imposing a concrete organization upon it like the boxes-within-boxes model is a bit of an over simplification. If you expanded the model to include the entire environment, my personal opinion is that it would over simplify the system to such a degree that the model would lose most of its usefulness. Not everything will fit in neat little boxes, or should be made to fit. Which isn't to say we don't do this already- we categorize and over simplify the world around us because it's in our nature to do so, but the method definitely has its problems.
Name: Kimberley Knudson
Date: 2004-04-19 03:12:27
Message Id: 9429
Over the weekend I was talking to some of my friends and an embarrassing story came up in the conversation. I automatically blushed and averted my eyes. I was thinking about this response and how strange it is. Sound waves from a voice enter my ear canal, hit my ear drum, cause vibrations in 3 tiny bones which in turn cause stimulation of different nerves in the organ of corti. These sensory nerves send signals to the auditory cortex where they are processed. The signals are then interpreted as something that I should have a defensive reaction to. Thus, blood rushes to my skin and I appear red. How fascinating!
Date: 2004-04-19 09:50:44
Message Id: 9432
I was really amazed to learn how much our brain fills in... how little of what we perceive to be seeing is actually there. I suppose it would be a sensory overload for us to actually be able to see, hear, and experience our surroundings completely, but I wonder what are missing out on, or misinterpreting because of this lack of completeness?
Date: 2004-04-19 14:48:59
Message Id: 9437
I have been thinking about sight, and what people have posted about blindness. I have two questions. One, I vaguely remember from my AP bio class discussing how the brain compensates for the loss of a sense. If I remember correctly, the composition of your brain cells can actually change. For example if you become blind and the "area" of your brain that deals with vision is no longer receiving signal, can those cells be usurped for other functions? I am not sure my other question about blindness is applicable,but I have always wondered about it. I believe most blind people see black, however I know that a friend of mine, who lost his sight because of macular degeneration, sees all white all the time, what causes this?
Name: Brad Corr
Subject: Power of suggestion
Date: 2004-04-19 14:52:17
Message Id: 9439
One thing that seems to pop up in various forum postings is the evident power of suggestion. Whether its from a dream, or the eyes, or an experiment with water, or whatever. we're fascinated with what our mind can "trick" us into. An example is another possible urban myth/possible nobel prize winning experiment. Ever hear about the one in which students were put in a room told they were being observed under the influence of alcohol, and given beer. Then the following week given the same experiment but there was no alcohol in the beer and the students still acted "intoxicated."
My point is that the power of suggestion is incredibly powerful. We are creating senses, thoughts, and reactions, to stimuli that aren't actually externally present. In such cases are we creating identical internal stimuli or are the stimuli different? Are the corollary discharge stimuli that we've learned about triggerering identical responses or are they in some way different. Clearly our subconcious is having a big part in the power of suggestion, but can we control it in any way or does it completely miss the I-box? How far can we make this power of suggesstion work? I know we can alter such things as our heart beat by power of suggestion, so could we go far enough to raise or lower it so much to kill ourselves by power of suggestion? Could we fight diseases like cancer with the power of suggestion? What are the limits?
Date: 2004-04-19 19:48:34
Message Id: 9445
I don't really know the answer to Brad's question, but recent studies seem to be suggesting that our emotional state can be important in the healing process. Dr. Jerome Groopman recently wrote a book about how hope can help ill patients. The book is called The Anatomy of Hope. Basically he claims that the with hope certain endorphines are produced in the body which help improve its ability to heal.
Subject: dreams and seeing
Date: 2004-04-19 21:15:07
Message Id: 9447
I was thinking a little bit about dreams and vision a bit. About dreams, Laura's comment about the line between reality and dreams got me thinking about times when I may have had a dream and perceived it as reality, although to this day there are a few things that I "remember," but can't fully tell whether they were dreams or not. In relation to vision, I was wondering whether people dream in 2D or 3D. I know it's kind of arbitrary, but I was thinking that since our brains fill in so much information for us already, the same must be true in our dreaming states, specifically because it is not reality that we experience. But, how are we able to see the things that are happening in our dreams, and is that experience different for everybody?
Name: m. fichman
Subject: eye dominance
Date: 2004-04-19 22:36:51
Message Id: 9449
I have been a baseball player/fan for most of my life. Often times, when discussing sight as it relates to hitting, people refer to a batter as left eye dominant or right eye dominant. This dominance has to do not with a greater sight capability in either eye, but with a preference for sighting with a particular eye. Usually, left eye dominant batters are left handed and vice versa. I have always equated batting preference (righty or lefty) with hand dominance (or brain hemisphere dominance). However, many feel that eye dominance is the determining trait- the argument being that sometimes left handed batters throw right handed or vice versa and point to the fact that there is a statistically higher incidence of cross-dominance in pro ball players than in the general population.
Date: 2004-04-19 23:04:54
Message Id: 9452
It is interesting how little our conscious brain has to do with the basic interpretation of sensory input. The system of vision seems so simple yet complicated at the same time. I'd really be interested in learning how the other sensory systems interpret sensory inputs. Do they also play tricks on our conscious level of understanding? Also, I have this sort of sixth sense in that when I walk into a room I can always tell if the television is on, even if I can't see it. It really bothers me that no one else seems to be able to detect this. Does this have something to do with a sound, or other input that I unconsciously interpret and recognize as coming from the television?
Subject: Eye Dominance
Date: 2004-04-19 23:32:16
Message Id: 9453
Like most of us, I've given sight a lot of thought this past week. I was only two when it was discovered that I needed glasses. (My aunt noticed that my right eye seemed to "move" when I was looking straight ahead. (Isn't it interesting that it had to be an "outsider" who noticed? My parents had gotten used to my lazy eye and so it appeared normal.) In any case, growing up I never felt I had any problems seeing despite the fact that I wore glasses. In fact, I had to be told when my right eye was moving--the "picture" I see looks no different when this happens!" Needless to say, I am left-eye dominant--although I am right handed and an extremely poor baseball player:)
I no longer wear glasses or any other form of visual aids--when I was nine it was decided that my vision really was perfect, my right eye simple drifts over once in a while. But remember that "experiment" we did in class? If position your finger in front of you and close one eye, it should move..Well, when I do this, it only moves if I close my left eye! There is absolutely no difference if I close my right eye--I discovered this randomly when I was about six and it's never seemed to bother anybody else but me:) The thing is, I really wonder if in my case, my right eye makes ANY difference to the picture compiled by my NS.
Subject: blindness..sharpened senses
Date: 2004-04-19 23:47:06
Message Id: 9454
In response to Ariel's post about the possibility of reorganized cells in the brain as a result of a "compensation for a lost sense," I might be able to offer some insight on this in that I have lost most of my functional hearing ability. In order to compensate for my lack of hearing, i did find that my vision was sharpened in that it was more sensitive. In other words, I did not develop the power to see further and more clearly than the typical person (no superman eyesight..unfortunately..), but I was able to interpret my visual cues more quickly and efficiently. My hearing loss makes me more observant and perceptive of body mannerisms, details etc that others would not normally notice. i had the ability to read lips amazingly well and from various angles, however, after receiving a device that has dramatically improved my hearing, my reliance on my vision has decreased considerably. As a result, not only can i not read lips as well as i could before but I am also not as driven to be visually focused visually on my surroundings 100 percent of the time.
My audiologist explained to me before my procedure that my brain would literally grow, or establish neural pathways once the hearing cortex of my brain became more stimulated. I would then guess that reorganization CAN occur on the basis of that particular sense being used or altered.
Date: 2004-04-20 01:13:27
Message Id: 9460
I think that the concept of our nervous system constantly resolving 2 states of conflict (i.e. between reporting of 2 different locations for an object) and making judgments in a 3rd dimension is really interesting. It seems that this phenomena occurs without the I-function as we cannot physically control the process by which these resolutions are made. Given this assumption, I was wondering if processes such as these, done by our sensory systems all the time, can only be done (to the degree we judge as acceptable--"normal") without the use of our I-function? I have tracking problems with my eyes and as a result, everything I see is shaky or tripled. I do not see too well in 3-D and have problems with depth perception. In other words, I sometimes clip walls or bump into them completely, miss a punch if I am trying to hit something, and have a hard time reading. However, this has been a problem for so long, that I am used to it and can, to a degree, compensate for my misjudgments. My conscience efforts to compensate for things I can't quite see but I know are there, pale in comparison to someone whose nervous system is constantly making the 3-D judgments without the I-function. If our nervous system is unable, for some reason, to resolve conflict, is it a result of not being able to gather enough information to make an accurate guess? It would seem that our I-function has no part in this assimilation of information...or does it? Lastly, are we ever aware of what our sensory systems are processing?
Date: 2004-04-20 01:21:19
Message Id: 9461
Kimberly's post got me curious about the phenomena of blushing. I did a google search for some basic information and found out that blind and deaf people blush as well. According to a website exploring the subject ( Why do we blush? ), Helen Keller blushed quite a bit-- despite being blind and deaf. How can a physiological response so closely linked to vision and auditory senses still occur in the absense of them? In Keller's case, the website suggests that blushing is a reflection of mental attitude rather than a response. If that is true, is blushing not a sensory response?? Or is Keller's experience an example of the brain one again finishing out the "picture" as it deems best (e.g. blindspot)?
Subject: eye dominance- again
Date: 2004-04-20 02:44:43
Message Id: 9466
The discussion of eye dominance reminded me of something that has always intruiged me: both my brother and I are right-handed, but we both bat left-handed. If this has something more to do with eye dominance than hand dominance, then this would make sense...except that I (at least) am right-eye dominant. Also, I'm right-footed and ambidexterous when it comes to golf, as is my brother. Although it's almost certain that this is something genetic, it gets even more weird when I say that my brother and I only share one common parent, my dad, who cannot do any of the things that we can. SO, it seems as if we both got some repressed traits of my father's- in fact, the exact same one(s)...kinda weird, isn't it?
Date: 2004-04-20 02:50:22
Message Id: 9467
Dana's posting regarding her lack of sensitivity to facial and social cues, made me think of Baren-Cohen's research. He proposed that women were a lot more capable of empathy and reading facial cues than men, who in turn, were a lot more capable of systemizing than women. He may be correct when it comes to biological inclinations of such skills; however, I believe that it is one's experiences throughout life that help develop either skill. For example, unlike Dana, I feel that I have a slightly above average skill of reading facial and social cues. This probably comes from my childhood experiences. I have moved around a lot, and have lived in four different countries on three different continents and have been to about 10 different schools. As a young child I have had an opportunity to interact with a wide range of different personalities and have been faced with many different social situations, all of which have helped heighten my social senses, or my capabilities of empathy, as Baren-Cohen would say.
Subject: Training of the Brain
Date: 2004-04-20 04:14:25
Message Id: 9469
I feel that many of the themes discussed in the forum this week relate significantly to the idea of "training the brain" to think a certain way. This so-called "training of the brain" is a response that arises to the mind as it continually receives and perceives negative cues. In order to alter repeated results, the brain attempts to use alternative approaches so to avoid negative responses, whether it be in the form of sadness, embarrassment, or failure. For example, in Dana's posting, I think if she repeatedly saw negative effects resulting from her inability "to see", I believe that her mind would make adjustments and she would begin to single out more social cues and become more observant of body language and facial expression. Therefore, her brain has learnt the ability to become more aware of body language and facial expression. This adjustment would be made in order to prevent associated negative emotions. Maja's ability "to see" could then be percieved as an outcome or training from her childhood experiences, and her desire to be as comfortable as possible in her changing environment. On the emotional, I think this is an active thought process. Although I have applied this to a social level, I think it can be understood more clearly by observing hearing and seeing impairments, as well as physical handicaps. On various popular talk shows, the media often showcases individuals that have overcome physical disabilities by overcompensation of another physical ability or trait. If a person has two legs amputated, they can walk around using their arms. Their arms grow strong enough to carry the weight of their body because of their desire and need to get around independently. Much like the brain filling in blind spots, its almost as if the brain "fills in" disabilities by improving other senses or physical aspects. It is this "filling-in" that can account for increased senses as a result of diminished or impaired one(s).
Name: Mridula Shankar
Subject: Magic Drawings, Perceptions and Reality
Date: 2004-04-20 04:18:51
Message Id: 9470
When we were shown the magic drawings in class on Thursday, it was interesting that many people in the class could only see one of the imbedded images. I, for instance could only see the skull in the image that had the skull/woman at her dressing table and it took me a considerable amount of time to perceive the image of the woman at her table. What is fascinating is that not only did many of us see just one image, but we each differed in our observation of the image shown to us. Is this discrepancy a function of a difference in the ability to perceive or is it accounted for by differences in the visual pathways leading to the brain? Is what we see reality or just an optical (perceptual) illusion? What makes us realize the difference between the two?
Subject: Knowing vs. KNOWING
Date: 2004-04-20 07:30:41
Message Id: 9472
Going off a conversation in class, I realize that there is a difference between knowing how to do something and KNOWING how to do something (being able to explain it to someone else). However, I do not think that KNOWING necessarily implies a better understanding. For example, writing has always been one of my friend's strongests abilities, she's an amazing writer. However, when tutoring one summer, she taught math. She did this because she couldn't explain to another person how to write, even though she was an amazing writer herself. Does the fact that she couldn't explain how to write in any way change or diminish her writing ability? I think not...
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