Forum Archive - Week 12
Learning from the blind spot ....
Name: Paul Grobstein
Username: pgrobste@brynmawr.edu
Subject: week n-1
Date: 2003-04-20 17:41:52
Message Id: 5446
Comments:
We've moved into new turf, the input side of the nervous system. And ... ? You're free as always to write about whatever you've been thinking about. Here's a starting point, though, if you'd like one ...
What are the implications for understanding nervous system organization of observations on the blind spot of the retina? For understanding behavior? What new questions do they raise?
Name: Tiffany Litvine
Username: tlitvine@brynmawr.edu
Subject: Extrasensory perception
Date: 2003-04-21 14:32:45
Message Id: 5452
Comments:
Thursday’s discussion brought some new insights into my understanding of the nervous system and its association to behavior. I was particularly intrigued by extrasensory perception. I was surprised to find out that we acquire information/knowledge without realizing we acquired it. At first I was hesitant about accepting this concept, but once we put it into practice using the blind spot as an example it made sense. The blind spot on our retina is supposed to produce a black spot in the images we perceive, but the nervous system creates an image for us. The nervous system invents/creates an image, which it believes, would normally be there. It is capable of making us perceive images differently than what they really are. Although the nervous system is capable of doing this, I found that in my case, its capacity to create images was somewhat limited. When I did the experiment with the red dots and the single yellow dot, I only saw red dots as my blind spot hit the yellow dot.
Therefore the nervous system seems unable to generate images that are too complex.What I found most intriguing is the fact that the nervous system generates outputs which we associate to our I-function. We think we perceive things the way we see them, but in fact it is our nervous system which is helping us create what we see. So how much of our perception of the world is controlled by our I-function if the nervous system can affect it without us knowing? Is that where hallucinations come from? If our nervous system can affect our perception of the world it seems plausible to assume that it can control our behavior as well. As the course is evolving, I feel increasingly comfortable with the fact the brain-behavior.
Name: Danielle McManus
Username: dmcmanus@brynmawr.edu
Subject:
Date: 2003-04-21 17:30:25
Message Id: 5455
Comments:
If we've seen (ha ha) that our sight is in part fudged by our nervous system without our I-function's knowledge, how about our other senses? I particularly wonder about taste--one chapter of Eric Schlosser's book Fast Food Nation talks about how chemicals are used to produce flavor. On a visit to a chemical lab, the author is handed a vial filled with a chemical mixture that gives him the striking impression that he's smelling hamburgers on the grill. It's that chemical additive that gives otherwise bland, frozen, over-processed food its good flavor--the chemicals (bear with me, my memory's fuzzy on the specifics here) release into your nasal cavity, triggering your sense of smell, which in turn relays its impression of smelling a grilled hamburger to the palate, which interprets the chemical's smell as a certain taste. Or something along those lines. Point is, in heavily processed foods, the food itself bears little relation to the flavor you're tasting--your sensation of taste isn't originating from your tastebuds, but from your sense of smell. But your I-function doesn't know this--it assumes that burger tastes like a burger, cause, well, it's a burger. Not because it's been decked out with chemicals. So how far can we trust our senses? Why isn't our I-function let in on all this conspiratorial fudging among the senses?
Name: geoff
Username: gpollitt@haverford.edu
Subject: if you can't trust your senses...
Date: 2003-04-21 21:03:58
Message Id: 5457
Comments:
danielle asks how far we can trust our senses. if we can simulate a certain smell with a chemical or mixture of chemicals then what is real? i have noticed this disparity between the I-function's analysis of a situation and something more base that may control some pretty heavy emotions (you may still feel hungry and salivate even though you know in your mind you are just smelling chemicals). we assume quite a bit about what is real and what is not.
maybe someday we will be able to have the full sensory experience of chewing the hamburger without putting anything in our mouths. this reminds me of studies that i think are still going on at Penn with drug abusers. we have all learned that drugs manipulate our behavior by interacting with the receptors in our brain, maybe causing a rush of dopamine in a synaptic cleft or blocking its reuptake. but these Penn studies have shown that you do not actually have to physically take in anything for you to experience the effects of the drug. it sounds like the placebo effect but it is a little bit different. the study has drug users who are off the drug (usually crack or heroine), watching videos of the neighborhoods where the drugs are sold or shown pictures of the needles and other equipment. the study found that this stimulus was enough for the subjects to experience being high, at least the initial stages of it. it is not that they felt withdrawal in anticipation of a hit, as i might have guessed, it is that the body was already making them high, just assuming that the drug would be coming. makes me wonder what the use of the drug is then, if the brain can make itself high. In theory the drug would not even be necessary if the I-function could convince the brain enough that the drug was there.
Name: alexandra
Username: alippman
Subject: Perception
Date: 2003-04-21 22:18:56
Message Id: 5463
Comments:
Although I knew that everyone has a blind spot in their vision, I was surprised at how sophisticated the masking of this fact is. The great extent in which we never notice that we do not see disturbs me a little. It seems like that would indicate that much of what we see or experience may be simply a product of our nervous system and have no basis in reality. That our eyes move around so much soothes me a little because if our blind-spot is always in a different spot, then reality seems like it would take over from the illusion which our mind had created.
Thinking about the variation in blindspot size or location also interested me. Do people have on average the same size of blindspots? I know this to be false because my father has told me that he has very large blindspots. Is size generally uniform though? Does the size of the blindspot change with age ever? Does the existence of larger eyespots actually lead to a decreased awareness of the world around them?
It seems to me that people must have different sizes of blindspots, which may or may not (I think not, for some reason) change with time. I doubt, however, that the halibut is ver gooo
Name: Grace Shin
Username: gshin@brynmawr.edu
Subject: different inputs
Date: 2003-04-21 22:46:57
Message Id: 5464
Comments:
I think it's really interesting to think that what I perceive as one thing may not be what others perceive it as. I was reminded of a movie (can't remember the title...) but I remember how in the movie the character always sensed things a bit different than everyone else and other people just thought he was weird... but after thinking about it, the simple truth that what i perceive as being yellow may not be the same yellow that you perceive! I guess our different inputs also make life interesting!
Regarding geoff's comment about tasting hamburgers one day without actually eating one takes into account the taste... but i think the joy of eating a hamburger comes from multiple inputs... i know for myself, the appearance of the food has a great impact on how it tastes, if i knew that my sister (who cannot cook...) made the food, i also would be more hesitant to say that it tastes good... so i don't know if that kind of technology (?) is possible... joys of eating without actually eating...
Name: Nicole
Username: nmegatul@brynmawr.edu
Subject: completely unrelated topic
Date: 2003-04-21 23:02:08
Message Id: 5466
Comments:
I'm sorry to get off the subject but since I was unable to attend both classes last week (because I was having an absolute blast in the health center), I can't comment on class discussion this week. Instead I'll just talk about some topic that has always baffled me. I am soooo embarrassed to admit this but while sitting in the waiting room at the health center, I watched part of a talk show hosting parents of dangerously obese (like 200lbs) children/toddlers. One of the issues was that the parents admitted that they enjoyed gorging their kids with excessive amounts of food, loved watching their kids pig out, and liked the attention that it brought them. I just had to wonder WHO would get enjoyment out of something so sick? This also applies to another disturbing illness, Munchausen syndrome, where a parent (usually the mom) will continually poison their child or fake illness so as to elicit attention. Typically Munchausen people don't show any symptoms of any other mental illness and are usually otherwise intelligent. It seems that attention and pity are the goals of these sick and abusive behaviors but why do these people lack the judgment, self-restraint, compassion etc. that would keep someone else from ever giving into such behavior even if they were to have some urge to do it? What causes such a warped desire to harm someone for attention or whatever other need they believe such abuse brings them? Why do these people pick children as their mode for attention when there are so many other ways to get noticed? Can their behavior be excused as a simple neurological imbalance or other biological problem? Even with the most detailed medical explanation, these behaviors would still perplex me. Sorry, this was probably the most non-sequitur post of the entire semester. Go back to talking about class discussions now.
Name: Laurel Jackson
Username: ljackson@brynmawr.edu
Subject:
Date: 2003-04-21 23:06:13
Message Id: 5467
Comments:
In regards to Alexandra's posting, I know for a fact that the amount of blind spots in vision increases with age. Does this mean, however, that the brain compensates for this loss, or the person just cannot see a clear picture anymore?
Also, in regards to our class discussion on Thursday about what is seeing, it made me think of an interesting story. My great-grandmother lived with my family for years. Even at 95, she still had her wits about her, except that she was considered completely blind, only being able to sense some light variation. She had problems sleeping, and one of the pills that her doctor prescribed her gave her hallucinations. She would tell us about the little children that were sitting at the foot of her bed, watching her as she fell asleep. She wasn't really bothered by them, just a little confused. My dad couldn't help but break up laughing: "Grandma, you're BLIND. What do you mean you SEE little children?" And she answered: "I know I'm blind, but they're there, and I see them." What part of her brain was producing the image that she "saw"? If it had nothing to do with light receptors or pupils or lenses, how did she "see"? Is it still sight if the real image is not actually there?
Name: vivian
Username: vbishay@brynmawr.edu
Subject:
Date: 2003-04-21 23:11:58
Message Id: 5468
Comments:
along the same lines as danielle's comments i've been thinking about the gaps in our various senses and how the nervous system fills them in without our i-functions knowledge. so there's ourself and the idea of ourself that the nervous system has and clearly they don't always coincide. prime example goes back to the phantom limb concept in which case the gap between the reality of the self and the nervous systems idea of self is very different...to the point where you could feel pain in a limb that doesn't even exist. that's pretty impressive. i've also been giving some thought to proprioreceptors. i kind of imagine the reafferent loop as our nervous systems sense of self - or at least that our proprioreceptors contribute in large part to the idea of self that our nervous system uses to fill in gaps in our perception, but if there is a gap in the information our proprioreceptors are relaying similar to our retina's 'blind spot' where does the nervous system aquire the information to fill it in?
Name: Kathleen
Username: kflanner@brynmawr.edu
Subject: tricks.
Date: 2003-04-21 23:27:28
Message Id: 5469
Comments:
Since we're on the topic of how our brain can sometimes trick us through toying with our senses, I'm reminded of last spring when my grandmother got glasses for the first time. She couldn't believe that my mother had "gotten old", that her own house looked slightly delapidated, and that she had as many wrinkles as she did. Her deteriorating vision had acted as a sort of safeguard for her, shielding her from some harsh realities. Her vision wasn't necessarily a "trick" or function of the brain, but it might as well have been.. as it affected her behavior so drastically.
Name: Annabella
Username: arutigli@hotmail.com
Subject: what is vision?
Date: 2003-04-21 23:43:29
Message Id: 5470
Comments:
Laurels question "what is vision?" is very interesting, especially when the implications of its answer are examined. Normally, vision is a referral to the sense of sight. But what about blind people that can "see" color? This is not the same type of vision that a person with 20/20 sight would have. Is this a hallucination? If so, can hallucination be a type of 'vision.' We've all heard the story of a stranded traveler 'seeing' a cool oasis, only to realize (after a mouthful of sand) that they were prey to illusions. From this we can understand that vision is not wholly reliant on our eyesight, but more on our "mindsight."
Interestingly enough, a new advance in the medical field helping people see, is to attach a machine that is able to process pictures, almost like a very tiny camera. This machine would be 'hooked' to the vision centers, and stimulate the brain to 'see.' Many blind parents, whom have blind offspring refuse to have this procedure done claiming that being blind is not a disability. They can still see, but not in the traditional sense. Which brings us back to the original question —what is vision?
Name: Neela
Username: nthirugn@brynmawr.edu
Subject:
Date: 2003-04-22 00:02:35
Message Id: 5471
Comments:
The discussion on the manipulation of the senses (seen naturally the blind spot or unnaturally in the case of the additive food chemicals) seems to compromise the level of trust we place in them and our nervous system as a whole. I think realizing that our perceptual abilities are limited and can be changed is valuable because we open ourselves up to possibilites, and perhaps behaviors, beyond those primarily dictated by our senses. Throughout the course, we've witnessed the power and influence of the brain; the more we understand it and the more we are able to control our nervous systems through conscious actions and science, the greater the capacity of the I-function becomes. I do realize that the statement is problematic because our I-function can never truly understand or control the total complexity of "the brain" (this borders on the much discussed topic of free will), but we've been attempting to do so for centuries; Science is the externalized product of our collective I-functions' attempt to comprehend, control and perhaps ultimately conquer that which we cannot explain within the nervous system and that which we cannot explain through our senses. In the recent age of technology, the focus seems to have shifted from understanding to controlling - we alter and create. These processes mirror the production of compensatory images our brain creates in order to create fill in our blind spot: they both seek a greater and more complete picture of what is "truly" present and make one up to do so.
Name: Melissa
Username: mosorio@brynmawr.edu
Subject: Blind Spots
Date: 2003-04-22 00:21:33
Message Id: 5473
Comments:
I found it particularly interesting to learn that we have a blind spot, in which our nervous system compensates for and creates an image to replace the absence. This brings up many interesting questions about the source of our behavior in terms of I-function. If we can experience or perceive things without the I-function maybe we have less control over our behavior than we think. It makes me wonder about how and what we perceive to be reality if our brain is capable of recreating or creating images. While this is an amazing function of the nervous system, it is also alittle scary/interesting to think about the other things that the nervous system is replacing or creating.
Name: enor wagner
Username: enorenor6@aol.com
Subject: implications of a blind spot
Date: 2003-04-22 01:09:05
Message Id: 5474
Comments:
A couple different things came to mind after class on Thursday. In response to our class experiment (the cross and the big colored in circle on the piece of paper), I found it amazing that the brain could create information which was merely a facade. What are the implications of that? First of all, there definately existed a specific distance wherein the mind switched from its willingness to see the dot in its peripheral vision to allowing the dot to disappear, replacing it with information based on conceptual intuition.
Is this exact distance true in other cases as well as this dot experiment? Is there a point when our brain fills in information that our senses can no longer obtain? Is that what accounts for people's more accurate hearing when they go blind? Does the mind fill in created information that we are not even aware of? After all, the information it filled in during the experiment seemed completely accurate in terms of its capability to replicate.
Name: Arun
Username: asingh@haverford.edu
Subject: Perception and the influence of other inputs
Date: 2003-04-22 01:32:37
Message Id: 5475
Comments:
I think that Anabella makes an interesting point on how vision seems to be more "mindsight" than "eyesight". This is an interesting notion as it brings about the question of what really is reality?
As I started considering the implications of this "created world", I realized that I was ignoring that in cases of 'perception', visual input is only part of the entire stimulus that enters our brains. I know the experiment we did in class was relevant to primarily visual inputs (as is the blindspot we have while driving) but in other instances, audio, tactile and other forms of inputs may help influence.
I was exploring the internet on perception by the brain and input senses and I actually came to a neurobiology and behavior discussion from a few years back where one girl talked about a study which happened in UC Santa Cruz a few years back. The scientists developed a computer animated character called "Baldy" which they have enabled to speak with extremely accurate lip movements. With Baldy they were able to do experiments in which they program Baldy to move his lips as if to say one phrase, but put it together with a recording of him saying something else. When they do this, they have found that the experiment subjects do not understand what Baldy is saying, indicating that perhaps there is more to understanding to speech than an audio input. This validates the idea that some of what we are talking about as "made up by the brain" may be a result of other impulses from other senses.
Name: Zunera
Username: Anonymous
Subject:
Date: 2003-04-22 01:51:59
Message Id: 5476
Comments:
The idea that the nervous system can add, manipulate, and incorporate information within and around us makes me wonder how this could play into memory.
I know that people can have "false memories" and that most of our memory is actually inaccurate (over time). How does this play into our every day functioning? We always try to take people at face value, when they say they "remember." Just today, while I was working at KoP, a woman came up to me with a dress, asking me if it was in any other size. She told me that she "remembered seeing a small...somewhere." After checking the rack she claimed to have seen the dress, I ended up looking in every rack and hold room (about 2 hours of pointless searching). The woman kept insisting she had seen the dress in another size, and began describing what other dresses were next to it, and what color those dresses were, etc. In the end, her daughter reminded her mother that she had seen the exact same dress in another store, and must have gotten confused.
How about in criminal cases, where witnesses are asked to "remember" the events? How much of that is actually real, and how much of it is a product of our nervous system generating its own output? There have been cases where young children, pressured by adults and other figure models (police, teachers) have falsely accused others of crimes simply by "remembering" actions/behaviors that turned out to be false.
The more time we spend on discussing how much the nervous system is capable of, the more I see the brain=behavior, especially if the nervous system can alter one's perception and understanding of the world around him/her (enough to make the person think/believe that the sensory input and output's created are real and "accurate").
Name: Christine Kaminski
Username: ckaminsk@brynmawr.edu
Subject: Red meets yellow
Date: 2003-04-22 01:57:07
Message Id: 5477
Comments:
I found the test, with the yellow dot surrounded by the red particularly interesting. While it seems that the blind spot should remain in fact yellow, it seems to be red to us. Why does this happen? The logical explanation seems to be that the brain takes all of its surrounding input and says "hey, look...there's a lot of red polka dots throughout...let's fill in the last dot with red to make this complete" Such a specific pattern where the color is uniform in all but the center convinces the mind that it should in fact be red since there is no other obvious pattern incorporating that yellow elsewhere. Perhaps if the square pattern for the test were larger and had more yellow dots in it, the brain might have a chance of actually wanting to have that middle dot be yellow, but as it stands, it wants to be red. The brain can thus be easily influenced/manipulated into believing certain things, yet there may not be sufficient evidence for it. The brain can quickly be influenced, leading to misinterpretation among many, often even resulting in confrontation/argument. This seems to be what often causes tension and disagreement among people, especially when everything is not taken into consideration and assumptions are made based on what the brain is programming itself to believe.
Name: Andy Greenberg
Username: agreenbe@haverford.edu
Subject: "Made-up" continuity
Date: 2003-04-22 02:29:23
Message Id: 5478
Comments:
The idea that our brain can artificially fill in the hole created by the optic nerve's entering the eye seems to me to be an example of a situation in which continuity that doesn't exist in the physical world exists in our minds. Another compelling question in this genre is "How does the brain created continuous experience from discrete mental events?" In both cases, when the brain creates a sensation of continuity spatially and temporally, there might be a case to be made that this difference in the sensation and the actually physical process is evidence that the mind cannot be the brain. An article that might be useful in this discussion can be found at www.jstor.org. It is entitled "Illusions of Experience," and it attempts to deal with these problems for materalism.
Name: marissa
Username: mlitman@brynmawr.edu
Subject: FOOD and Flavor
Date: 2003-04-22 02:40:44
Message Id: 5479
Comments:
I thought the idea of chemicals and fast food and flavor was very interesting. I myself am a very finicky eater and immediately when I smell certain things, regardless of what they may be, I will not consume them. However, I love junk food, I love fast food, I cravbe fast food. The comments on the clueless I-Function in reference to what is actually being consumed, not only startled me in terms of what my body is consuming, but also made me question why in the world I eat certain things that I know are totally artificial. Another thought I had was in regards to Astronaut's food in space, which is basically fake, chemically enhanced "food" products and or basically frozen goods. Are astronauts truly expereincing a flavor when they consume whatever is in those packets or pills, or is it all in their sense of small and their brain telling them that it tastes a certain way. I know myself that it is possible to make yourself abhorred to certain foods, but is that a function of the senses or the oblivious I-Function?
Name: kat mccormick
Username: kmccormi@brynmawr.edu
Subject:
Date: 2003-04-22 02:43:18
Message Id: 5480
Comments:
As we talked in class and the conversation has continued on the forum, it has become evident that we percieve things of which we are not aware, and our illusion of awareness can lead us astray. The examples have been plentiful: chemicals that smell like hamburgers, women who think they have seen dresses which are not there, ect...
All this talk of our deceptive senses reminded me of the beginnig of Descartes' Meditations, in which he claims that we should disregard all that we know on the basis that our senses are faulty. Although I had formerly only thought of this claim of Descartes' in a philosophical sense (ha), I have since begun to wonder over the neurological support for the separation between what we physiologically percieve, and the perceptions of our I-functions. Does Descartes have more of a point than I give him credit for?
Name: Adina
Username: acazaban@bmc
Subject: mind vs. brain
Date: 2003-04-22 04:04:44
Message Id: 5481
Comments:
In his posting, Andy mentions that the brain creates a continuity from discrete mental events, and how this must make the brain different from the brain. I found this particularly interestin since I, too, have been thinking about the brain vs. the mind for some time now. In my view, the mind is the I-function; it is made up of all of our ideas and feelings. I used to think that it was just the mind that controled behavior, since whenever I thought about the mind, it meant the same thing to me as the brain. However, upon taking this class we have learned about all kinds of different ways in which the brain and nervous system do things that the I-function is completely unaware of. This new example of our eyes covering over our blind spots so that we always see something, without our being aware of it, is just another peice of evidence that, in fact, mind does not equal brain. I now see it situation as being two concentric cirles. The mind is a part of the brain, but the brain is also made up of much more that the mind has no part of. Now, I think that the mind is a great factor of behavior, but the rest of the brain, the parts that we are unaware of, are also involved in every decision that we make. This idea leads to another question. If there are factors that we are unaware of, and that we cannot change, in our decisions, are we really free? Personally, I like to think that free will and freedom do exist, but the more I learn about the brain, and the more I think about it, the harder it is for me to think of myself as free. I still "feel" free, but that is just because I am an optimist, and I like to think that new evidence will arrise that will support the idea that I believe in. However, the more I learn, the more shaken my faith gets.
Name: Jen
Username: jhansen@brynmawr.edu
Subject: blind spot
Date: 2003-04-22 04:11:46
Message Id: 5482
Comments:
The blind spot poses an interesting point because we don't even see that we don't see at this point because our brain automatically fills it in. This demonstrates that the brain favors the process of completion, an extremely complex ability of the visual system, which has far reaching consequences for the entire perceptive system, is dependent on the context of the picture. Our brain seems to patch the hole caused by the lack of receptors in the Blind Spot with information it gleans from adjacent receptors.
The completion process can in other areas of our perception where we might also fill other holes. We are, however, always dependent on the context. For example, if one leaves out the letter 'e' in the rst of this sntnc, you ar still abl to undrstand what th sntnc mans. This proves the important point that completion is usually a very useful mechanism, but it doesn't always function correctly with respect to reality. I compare this phenomenon to that of a magic trick because the process of completion resembles an illusion.
Name: Stephanie
Username: srichard@brynmawr.edu
Subject:
Date: 2003-04-22 06:37:11
Message Id: 5484
Comments:
I think it's interesting that we talk about how our I-functions are tricked, because we able to fill in a blind spot or make apiece of cardboard taste like a hamburger. but that even when our I-functions know that there is a trick involved the result are still the same. I know we've talked about this before, but think it is amazing that the human mind is able to use it's knowledge against itself. Another human brain figured out how to make that probably barely edible pattie taste like a hamburger, or a series of still pictures look like a smooth action (animation). Don't a lot of medicines work on similiar principles of fooling the brain into believing something that isn't true? Even thought we know this, the illusion is still successful. It reminds me of the character in the Matrix who knows that the matrix isn't real, he knows the steak he is eating isn't steak, but he would rather enjoy that than the harsher realities of life. As science becomes more advanced and we kearn how to fool the mind more and more, it suppose we will have to make a similiar decision.
Name: Michelle Coleman
Username: mcoleman@haverford.edu
Subject: Baldy Exper. and Corollary Discharge
Date: 2003-04-22 06:38:57
Message Id: 5485
Comments:
Arun's idea of the Baldy program raises interesting ideas about our ability to perceive. Thinking critically about the mitch-match between visual lip movements and the actual auditory sound they emit provides a basis from which we might re-explore ideas of corollary discharge and its role in audio-visual perception. In many cases of Schizophrenia, auditory hallucinations are said to occur from deficits in the corollary discharge system, where patients are incapable of distinguishing thought (covert) from spoke (overt) speech.
Could the Baldy experimentations be simply providing a secure argument for the existence of internal monitors for perception such as the corollary discharge system?
Name:
Username: Anonymous
Subject:
Date: 2003-04-22 07:15:42
Message Id: 5486
Comments:
I recently wrote my web paper on the notion of change blindness, a phenomenon in which we essentially fail to be aware of alterations in an observed object or environment when "looking" is interrupted momentarily by saccade, both real and artificially created. This occurrence is incredible in its demonstration of the capacity of our sensory systems to be absolutely governed by the brain alone. Change blindness has been demonstrated repeatedly in both experimentally designed situations as well as everyday occurrences. For example, many people who have been in car accidents describe having simply not seen another vehicle or having been entirely unaware of the presence of a large object in their path. Although these may seem like excuses or the results of carelessness, the processing of the human brain legitimates these claims by occurring in such a way that changes in objects or surroundings which are "physically" observed can be deleted from visual short term memory under certain conditions and neglected entirely by our visual perception. My investigation of change blindness has certainly increased my belief in the brain=behavior notion. The very act of seeing which we believe to be almost entirely under our conscious control appears to be almost exclusively dependent upon the functionality of the brain. And yet, the documented dependence of visual perception upon directed attention to an object or environment leaves plenty of room for the members of our class to insert the concept of free will...
Many interesting links are available on the Internet to give demonstrations of the effects of change blindness. Here is a link to a particularly well-organized one.
Change Blindness Demo.
Name: Erin Fulchiero
Username: efulchie@brynmawr.edu
Subject: Change Blindness
Date: 2003-04-22 07:19:55
Message Id: 5487
Comments:
My posting regarding change blindness is directly above this one. Sorry.
Name: Cordelia Stearns
Username: cstearns@brynmawr.edu
Subject: trusting ourselves
Date: 2003-04-22 08:14:29
Message Id: 5488
Comments:
The notion of whether filling in the blind spot and being change blind should make us more wary of "trusting" our own brain is really interesting to me. It would be pretty depressing if we completely gave up on trusting our senses. I guess we couldn't survive if that were the case. But I went to Erin's change blindness site and tried some of the experiments, and failed pretty miserably as I was supposed to. It is really difficult to deal with that kind of failure. I wrote my last paper on people with anosognosia, who did not know that they were paralyzed or had left side visual neglect. One man totally denied his left neglect until occupational therapists used a virtual reality game with him simulating street crossing. The man frequently had "accidents", since he did not notice cars coming on his left side. The "accidents" in the game were accompanied by huge crashes and noises and flashing lights. For some reason, this made it finally click with the man that he could no longer trust his own perception. His response was described as extraordinarily emotional and tragic. And how could it not be? We have these few windows with which to experience the world. Certainly they can be tricked, but they do manage to do their job amazingly well most of the time. I just thought of another example. In Dr. Hollyday's class, she told us that if you cut the optic nerve of a frog and rotate the eye in its socket, the nerves of the eye will reattach to the correct parts of the tectum. However, since they are dislocated, this will cause the frog to see everything "wrong", so if a fly is at 5 o'clock in reality, the frog will send its tongue to 11 o'clock. It NEVER learns not to trust its vision, and eventually will starve to death.
Name: Kelvey
Username: krichard@brynmawr.edu
Subject:
Date: 2003-04-22 08:28:39
Message Id: 5490
Comments:
Today the radio hosts began discussing if there was a difference between addiction and obsessive compulsive. They were trying to think if maybe one was from birth while the other was environmentally induced. Is there a distinction?
Is mental illness often teh result of the minds attempt to make sense out of otherwise nonsensical inputs and in order to do that certain behavior 'surface'. To fill in the blind spot seems to be the brains way of making sense out of something that would otherwise be just patches of information. Blending things makes it easier to absorb rather than seperate inputs. If everything was split into distinct inputs without any connection there may be constant sensory overload- as seen in autism.
Name:
Username: imoissiu@brynmawr.edu
Subject:
Date: 2003-04-22 08:55:14
Message Id: 5491
Comments:
I don't understand how the brain makes up information to make up for the information lost in our blind spot. I never thought the brain would make up information (unless you are crazy). And how does the brain know what to put in that spot? I realize that it takes information from the surrounding environment, but still..... Very interesting.
Name: Katherine
Username: klafranc@brynhmawr.edu
Subject: translation
Date: 2003-04-22 09:30:06
Message Id: 5493
Comments:
Our comments this week about "what is real" really start to shake the foundations of things as we perceive them. We often assume to take sense perception as a starting point and as the basis for organizing the rest of our world. But if sense perceptions cannot be trusted, what does that mean? Despite my consistent concern for the uncertain place and existence of free will, I am not overly surprised by the "tricks" of the senses, after thinking for a bit about this phenomenon. What, afterall, is the place of art? The production of art, as in painting or writing for example, ultimately serves as a means of "translation"—translation of perception from one mind to another (and to itself). This act of translation is something we are doing all the time, even without realizing. We are constantly transforming aspects of the world into forms that might fit into the machine of our brains. And, as we have mentioned, everyone's machine is different. This means that even after an image is transformed from its world-form into the language of our brains, it must repeatedly be transformed again in each different brain that it encounters.
What were Monet and the impressionists saying when they began painting unfamiliar and blurry images? They were translating what they claimed to see, and were indirectly demanding that others question their own automatic and familiar translations. I believe that the world can remain viable only on the basis of continued questioning. It seems that the uncertainty of sense perceptions can act as a reminder to include these questions.
As it is, we realize that we must deal with the gap within our own brains (between the I-function's reality and the nervous systems's reality), just as we must deal with the eternal gap between different human minds. We have ways of mediation and bridging the gap, of course, like voice and art and inquiry, and it seems to me we have a responsibility to employ these means. The whole situation though reminds me of the final lines of Milton's Paradise Lost, where the two characters walk away from us, and "...hand in hand...took their solitary way." It seems that, at least to some extent, those two characters have found a workable balance between the gap. Perhaps we can do the same.
| Course Home Page
| Course Forum | Brain and
Behavior | Serendip Home |
Send us your comments at Serendip
© by Serendip 1994-
- Last Modified:
Wednesday, 02-May-2018 10:53:04 CDT
