Biology 202
Neurobiology and Behavior
Spring 2001

Forum Archive - Week 7-8

What implications follow from observations made in relation to the blindspot? With regard to vision, to "perception" in general, to the "I-function"?


Name: Paul Grobstein
Username: pgrobste@brynmawr.edu
Subject: week 8
Date: Fri Mar 23 09:02:22 EST 2001
Comments:
So ... welcome back to the forum area. And to a new part of the course. We've explored (at least to some extent) the output side of the nervous system, started looking at the input side, and run immediately into the blindspot. As always, you can write this week about whatever's on your mind but, if you need some incentive, how about ...

What implications follow from observations made in relation to the blindspot? With regard to vision, to "perception" in general, to the "I-function"?


Name: Huma
Username: hrana@brynmawr.edu
Subject: Driving
Date: Fri Mar 23 14:00:41 EST 2001
Comments:
The discussion on blindspots reminds me of my troubles with driving. Although I had gotten my driver's license three years ago, I did not really start driving until this summer. I remember, being completely shocked and frightened that I could see so little from inside of my car. There were blind spots everywhere and the car itself was a barrier to seeing other cars zipping by. The mere thought of driving in darkness or rain made me want to pull over in terror. Until this point, I hadn't had any idea that there was so much guessing/estimating involved in driving. Now, that I am a more experienced driver, I feel comfortable driving in various conditions (although i'm still not perfect). However, it's not that the structure of the car has changed in any way to make the task easier, but my ability to perceive other cars has increased. This makes me wonder if the "making up" factor of vision is innate or whether it is a skill which develops with practice and over time. From my experience, it seems as though it is harnessed and practiced. This, however, would imply that babies are practically blind...which doesn't seem quite right to me.
Name: Jess
Username: jamiller@brynmawr.edu
Subject: blind spot
Date: Sat Mar 24 18:26:41 EST 2001
Comments:
I agree with the last comments, blind spots in driving can seriously hinder your abilities as a driver, possibly, due more to the fear that we don't know what is out there and the fact that it is disconcerting, more than what we actually don't see. Maybe by filling in the blind spot in our vision, the brain is keeping us from living with this disconcerting phenomenon day in and day out. As far as implications go, it definitly seems as if there are parts of the brain which make decisions with out the I function, but maybe more so which predict how the I-function will react to certain stimuli and inturn alter the perception to best suit it. Now, that is confusing to think about. Could our minds actually be working around the I-function, like workers around a cranky boss, predicting and working around its reaction before something uncomfortable occurs.
Name: Kristine
Username: Kristineh44@hotmail.com
Subject: blind spots
Date: Sun Mar 25 17:43:31 EST 2001
Comments:
Yes, the blind-spot-in-the-car does appear to provide the perfect analogy of what vision would feel like without our brain's wonderful capactiy to "make stuff up." The uneasiness elicited by ambiguity is a powerful force indeed. In fact, I sometimes think the resolution of ambiguity is some sort of universal motivation, inherent, on some level anyway, in all human beings. It is not surprising, therefore, that we would demonstrate this phenomenon in one of our most basic, yet most crucial dimensions of perception.

To me, more than anything, this blindspot illustrates our ever-present tendency to be wrong, misguided, or one-sided when it comes to perception in general, and our subsequent need as scientists, or just as human beings, to questions our own beliefs. While I am guessing that we do not have tangible holes in our brains that can be likened to the holes in our retinas (although I wonder about some people!), I do think that we all have holes in our cognition, or I-function processes that we like to putty over with rationalizations or made-up stuff to absorb the harsh impact of cars we can't see coming.


Name: Matt Fisher
Username: mfisher@hvarford.edu
Subject: eye thoughts
Date: Sun Mar 25 19:51:04 EST 2001
Comments:
The blind spot discussion made me aware of many new possibilities within the brain. It is an incredibly powerful processor that makes up a lot of information. Does this imply that the brain creates reality? This gives a lot of credence to philosophy and its suggestions that nothing is real. The brain makes up a lot of the world humans perceive and does it arbitrarily. The experiment with the cross and dot shows this. It fills in a blank spot with whatever it sees fit. If there is something wrong with a person's brain what could stop the brain from putting a completely random filler into the area. What we normally see as a continuation of the background could become an entirely new thing. The blind spot is a kin of scary concept because of this due to the invention of sight by the brain.

Another point I found interesting about the eye discussion was the unconscious interpretation of signs. It was neat to know why people look at the eyes of other people and can tell things about them. This brings to mind scenes from so many movies where the lovers gaze into each other's eyes and see the love between them. I never knew before that it was really a true phenomenon.


Name: Gwen Slaughter
Username: gslaught@haverford.edu
Subject: blind spots
Date: Sun Mar 25 20:06:45 EST 2001
Comments:
At first I was kind of freaked out by the eye experiment we did in class and the ones I did later on the computer. Why was my brain doing this? Why did my eye have a blind spot in the first place? And, how did my brain know how to compensate for it? I don't have a problem accepting that the brain functions outside of the 'I-function.' There are numerous things the brain does that are outside our consciousness, such as immediate reactions to a painful stimulus. So, it I accept that our brains have this power. I guess I would like to know more about why we have this blind spot to begin with.
Name: Dena
Username: dgu@brynmawr.edu
Subject: Watching Oscars, glad there is no hole in the picture
Date: Sun Mar 25 20:43:30 EST 2001
Comments:
I think I read the blind spot is there because the optic nerve leaving the eyeball makes it impossible to have any cones or rods in that area. Though it is kinda scary, I suppose you canít avoid it and just have to adapt to it. I was actually thinking more about how you donít really ever look at one spot all the time, and that your eyes kinda jumps all over the place. At least, I know my eyes are always moving from place to place and focusing on different things. I was wondering if that cuts down on how much the brain actually makes up to replace what is missed by the blind spot. After all, if your eyes are always moving, then the blind spot is always moving around and what was missing in one frame is not what is missing the next frame. In that case, your brain is just kinda remembering what you saw in before to put in the missing spot. Sure the brain could mess up the images sometimes and you get some picture that isnít really there, but Iím hoping evolution has made our brain able to handle the task without too much problems.

The blind spot is probably more of a problem because our eyes donít really move around that much when we swing our head around to check for cars before changing lanes. Itís so quick; that our eyes only see one frame and the missing chunk of information could be very dangerous. So when I think of the blind spot, Iím really glad that our eyes and brain can work together to make the images of the world around us complete, to the best of our ability.


Name: Alexis Webb
Username: awebb@brynmawr.edu
Subject: Is Perception Really Seeing?
Date: Sun Mar 25 22:05:09 EST 2001
Comments:

The idea of blind spot is intriguing in that it does show just how much the brain generates by itself. In reading what Matt brought up about philosophy, I was reminded of something I read in high school, which initially piqued my curiousity for neuroscience. Take the following situation:

A neuroscientist is completely colorblind. She has never physically seen the color red, but she does know how the brain works, how the color receptors in our eyes work, so she knows HOW to see red. The question posed is: is the neuroscientist able to perceive red simply by understanding the method by which it happens? Is she conscious of a color that she's never seen?

Our brains allow us to fill in blanks. Part of perception is the ability to do this, i.e. the blind spot. But is perception really seeing? Like the scenario suggests, understanding does not necessarily allow for experience. Even though we know that we are not truly seeing everything that our perception tells us we are, we don't suddenly stop filling in those holes, which is probably a good thing.It seems to me that perception brings up many questions about what the brain is really doing, questions that move away from biology and behavior into more speculative realms.


Name: Sarah
Username: smccawle@brynmawr.edu
Subject: Perception
Date: Sun Mar 25 22:30:09 EST 2001
Comments:
I never thought that everyone's perception of reality was the same, but it is a little scary to think that what I see (my perception)is not really what is there. It amazes me that the brain can create so much that isn't there, so that we have something that we think is there. It is an unnerving idea and yet a fascinating one. The fact that our brain is capable of such an amazing feat and that we know it can do this is just another small step in understanding the complexity of who we are. Knowing about the Blind Spot does help to explain certian things about every day life, like when you see something out of the corner of your eye and then when you see full on it is not at all what you thought it was. All I have to say is that I am glad that our brain is capable of such an amazing feat. What a horrible thing it would be if we really did have a huge black spot for things in our peripheral vision.
Name: avis brennan
Username: abrennan@haverford.edu
Subject: blind spot
Date: Sun Mar 25 23:05:32 EST 2001
Comments:
The blind spot raises some interesting evolutionary questions. When driving, or in unfamiliar territory, it seems that this deficit of incoming (accurate?) visual information can be a dangerous handicap. However, it seems that our brains have adapted by working to fill in the missing pieces of information. And this ability seems to hold true in other capacities. Just as we see an entire image, the holes in our memories are usually patched. Also, I believe the eye-movements involved with reading follow similar principals. If I remember correctly, our eyes skip across points on a page and recognition of the words is possible without acknowledgement of each individual letter. This seems like ultimate efficiency. So perhaps the blind spot does not represent an evolutionary flaw, but instead acts to prime the brain for its important patchwork and accommodation duties.
Name: Daniel
Username: dburdick@brynmawr.edu
Subject: a paradox
Date: Sun Mar 25 23:38:53 EST 2001
Comments:
I'd like to address a paradox that I've observed in myself and perhaps see if others have had similar experiences. It seems that for most of my life, I've been trusting that which isn't there and not trusting that which is. That might be overstating it a bit, but I think the statement is still true. Here I've been, blindly accepting that what I see is there, when in fact, a significant portion of my vision -- that in my blind spot -- is entirely fabricated. Fortunately, my brain is efficient enough at guessing and the stuff I look at is consistent enough in its patterns that my brain's guesses are right most of the time (Serendip's displays notwithstanding). Still, this rationalization isn't what I go around thinking. Even knowing that I have a blind spot, I still go around pretty much without thinking about it at all, and believing that what I see is really there.

On the flip side, I have not historically trusted that which (apparently) is there and is seen by some part of my NS, but which "I" don't see. Call it intuition or "getting a feeling" - I've never quite believed it, although now I'm told it's based on real information. The example of staring into a lover's (or a potential lover's) eyes is a good one; certainly, I've gotten a feel for someone's interest before based on certain visual cues, but since I wasn't aware of it, I often dismissed it. It was almost certainly real, but I didn't trust it, whereas the vision in my blind spot is not real, but I do trust it.

This all seems somewhat contradictory, but of course, it's not really; it just reinforces the strength of the I-function. "I" believe what "I" am aware of. Actually, now that I think of it, this may not be true for others. Certainly, a lot of people believe pretty strongly in things they can't "be aware of," and a lot of behavior in many people is determined by intuition. This sort of goes to the question raised on Tuesday about the purpose of the I-function: if many behaviors are better performed without the involvement of the I-function, why do we need it at all? To extend this question, sometimes it seems that I would actually be better off without an I-function. It certainly inhibits a lot of potentially beneficial behavior -- acting on a relationship intuition, say, or even volunteering an extemporaneous comment in class.

My point is not to turn this into my own little therapy session though; my point is that this inhibition of behavior is a likely candidate to explain the existence of the I-function. When we think about things, that is, when we involve the I-function, we come to understand how actions will affect our livelihood. Making it personal in this way can lead to pretty strong emotions that would not be there if we were to act automatically. These emotions that are generated by the involvement of the I-function are often what inhibits certain behaviors, and from an evolutionary standpoint, it's probably better to do too little than to do too much, in much the same way as the nervous system's homeostatic mechanism works to keep things the same. That's all pretty much based on hypothesis and personal experience, though.


Name: Euree Choi
Username: echoi@brynmawr.edu
Subject: To see or to believe...
Date: Mon Mar 26 16:41:04 EST 2001
Comments:
Part of the reason we cannot see our blindspots is that our brains do not allow us to do so. Maybe it is possible that there is an inhibiting mechanism within our visual system causing these gaps in our perception. If our brains are filling in the missing information created from our blindspots, are we imagining reality? While reading other comments, I found that Matt had a similar question-"Does this imply that the brain creates reality?" Maybe a definition for perception would be the construction of one's own version of reality on the basis of information provided through the five prominent senses, since what we perceive is usually limited to our awareness. If our brains are creating reality, is seeing necessarily believing?

A thought came to mind after Tuesday's class. When we talked about telepathy and twins, I remembered watching the Oprah Winfrey Show years ago about a set of twins. One of the twins experienced pregnancy pains of the other twin (who was giving birth). In this situation, could it be that their I-functions or their cells had split genetically during mitosis? It's all so fascinating to me.


Name: Andrea
Username: n2tiv@aol.com
Subject: filling in the blanks
Date: Mon Mar 26 16:57:18 EST 2001
Comments:
Yes, I agree that the brain "substantially adds stuff to the report it gets from the eye" and I wonder how often the "made up" stuff is constructed directly from the incoming stimulus (logically filling in the blanks with a continuous image) and how often it is made of prior learning or even expectations. It would seem that some instances pull for immediate stimulus (ie, when we look at a field of dots and construct another dot in the blind spot when there isnt actually one there), but what about ambiguous figures? in an "old lady/young lady" ambiguous figure, the mind makes sense of the incoming data based on expectations of what the eye will see--what it makes up is not input, but interpretation, I guess. But I could imagine situations where the brain might "add information" to degraded stimulus in order to complete the picture. I believe there are studies (in the psych literature) that show how people fill in details of degraded stimulus to create "whole images." another question regarding the "fill in the blank" situation: what mechanisms operate in the brain to "tell it" to fill in the blind spot with similar information? Ie, why does the brain fill in a spot, just because there are spots all around it? And in the degraded stimulus situation, its more complex than that -- its not like replicating "another spot" thats just like the rest being filled in, its stuff thats not directly contained in the stim, like extra curves and angles, and lines. Gestalt psychologists have explained this phenomena with principle of continuity (that things are seen as continuous wholes whenever possible) but I do not understand on a brain level WHY this is true, or HOW the brain fills in details that are not directly given in the stim around it.
Name: caroline ridgway
Username: cridgway@haverford.edu
Subject: sight and seeing
Date: Mon Mar 26 16:57:58 EST 2001
Comments:
How might we relate the nervous sytem's ability to see images and the I-function's ability to synthesize and interpret them? From the exercise we did in class it is clear that the brain does a lot totally independently from any sense of an I. When I look out into the world, the neurons somehow fire in such a pattern as to create a cohesive image. Is it the brain or the I-function that allows us to have an understanding of how the rest of the world around us appears? Though the information currently being presented to my visual field is all that I "see," I am not without some sense of what I would then "see" if I were to turn my head 90 degrees to the right or left, or if I were to turn around completely. And I find this to be somewhat true for even novel environments. In general, though clearly not entirely, we are able to anticipate the way a given situation will appear to us visually. Moreover, when considering an impending event, we are able to create in our mind's eye an image of what me might expect to see. This is largely possible because of past experience, but we are then able to mix and match information to create a completely new scenario. And, at times, when what we are presented with does not match our expectations, we are surprised, as if the image we created in our heads were actually that which existed. How does this correspond to the activity of the nervous system vs. the I-function?
Name: Niru Kumar
Username: nkumar@brynmawr.edu
Subject: blindspots and non-objective reality
Date: Mon Mar 26 17:29:23 EST 2001
Comments:
In my web paper on synesthesia I found that our perceptions are largely individual to the extent that some people's perceptions are intermingled. Another thing I discovered was that the amount and type of intermingling was different for each person, because each person's nervous system considers different aspects of perception to be significant. The idea of a blindspot--compensated for by the I-function reinforces this concept even further. Reality, then, may not be the objective standard I previously held it to be, based purely on consequences of our physical differences. This non-objectivity of perception accounts for so many individual differences that exist--created by the random differences in our genetics that are the source of all difference among life on the planet. Physically, we each have a blindspot (I was so intrigued by this that I made all my friends try this out at dinner that day, much to their annoyance) but as the computer games on serendip progress we learn that the size of that blindspot varies for each individual. How do I even know to what extent my I-function is just making up my reality and to what extent reality is real..even though it seems like this observation makes life make more sense.

Although, in some ways this notion really calls the nature of the I-function into question. If the I-function is altering reality, but the I-function is based on observations of reality..what is altering what? It just seems very circular. The only way I really conceive of the I-function is as my thinking self. The part I know about, but my I-function fills in the detail of my blindspot without me knowing about it. If that is true, then what am I?


Name: Alice Goff
Username: agoff@brynmawr.edu
Subject: Perception Symphony
Date: Mon Mar 26 18:30:58 EST 2001
Comments:
I am particularly interested by this idea of the brain "making up" information. As many have mentioned, it gives an interesting slant on how much of what we see is actually there. However, as I started considering the implications of such a possiblity, I realized that I was ignoring that in so many cases of 'perception', the visual input is only part of the entire stimulus that enters our brains. Could it be possible that what we see is actually the result of not only visual inputs, but also of audio, tactile or other ones? I started to remember a lecture I heard in the 10th grade about research being done at UC Santa Cruz in which a few people are developing theories that part of listening and understanding people talk is seeing their mouths move. These scientists have 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.

Besides what this could tell us about the brain, this research is being used as a means to help deaf children learn to speak. The children watch Baldy moving his mouth on a computer and then imitate his lip and tongue movements to produce sounds. There is lots more information on the following website: http://mambo.ucsc.edu/psl/pslfan.html . You can also access a clip of Diane Sawyer as animated by the scientists for PrimeTime, which is especially amusing.

So, I think I just wanted to put this out there-- that some of what we are talking about as "made up by the brain" may be a result of other impulses from other senses. I am not arguing that this is always the case-- what other senses could be involved in looking at a black line? Still, it makes me feel a little better to know that how we percieve the world cannot be a complete hoax.


Name: Mary
Username: mferrell@brynmawr.edu
Subject: TV show on our subject
Date: Mon Mar 26 18:41:34 EST 2001
Comments:
For you information -- there's a Scientific American show on WHYY Tuesday night at 9 on the subject of reengineering the human body;nerve regeneration. Hosted by Alan Alda and Christopher Reeve.
Name: ingrid
Username: ladybasti@aol.com
Subject: 2 questions i had in class
Date: Mon Mar 26 19:16:56 EST 2001
Comments:
Why would evolution Ever make our iris some random colour? It's just muscle, right? Why would it be different from any of the others?

Also, what about the...something... (Not eye function, but not direct stimulation) that somehow, in our head, matches up the 2 views of our eyes? The thing that we see in our brain is Neither of the images on either of our eyes, but a Perfectly overlapping mix of the two. That's pretty incredible, how does that happen?


Name: anonymous
Username:
Subject: heh..whoops
Date: Mon Mar 26 19:18:03 EST 2001
Comments:
ehem..i mean "I function"... silly me, getting distracted.
Name: sural shah
Username: skshah@brynmawr.edu
Subject: blindspots everywhere!
Date: Mon Mar 26 19:37:55 EST 2001
Comments:
During our discussion in class on Tuesday concerning blindspots in vision, I became intrigued by the notion of blindspots of sorts existing in other aspects of our perception of the universe both around and within us. In talking to Dr. Grobstein about the idea of "blind"spots of touch or sound, we concluded that it is certainly likely that the brain must not only "repair" gaps in visual stimuli, but also within that of the other senses. This all is pretty amazing when you consider potentially how much of your world might be "tricks" played by your brain!! Looking at Daniel's examples of trusting cues you shouldn't and not trusting ones that you should...well, it's no wonder that we're often confused when our brains often make up cues that we later discover aren't true (as anyone who's ever been the victim of an accident involving a person who didn't check their blindspot would certainly agree...).

In looking over the comments, I was also interested by Alice's input. Based on the research that she discussed, I am convinced that at least some aspects of the making up of reality can be attributed to clues from other senses, but it can't be possible that they all are. After all, with the examples on Serendip and even our blindspot problem, the only cues are visual; there are no tactile or audio perceptions to be had. In support of the research with Baldy, though, I have been thinking about the role of synesthesia as an associated process. Could synesthesia be the result of similar processes in which cues from one or another sense are used to creat a signal to another sense?

In terms of the I-function, these thoughts are really significant. As others have mentioned, so much of our perception of reality and, in effect, our behaviors (even ones we are aware of) are the result of a fabricated universe. The thing to remember, however, is that the I-function can override instincts in many, albeit not all, cases, and that without the I-function, we wouldn't even be having this discussion. In pondering the look in lovers' eyes, etc. etc., it would seem to me that without the I-function, the feeling of love (specifically love, not just lust) may not even be possible. Depending on your concept of love, I can see this as being debatable, but the physical cues which signify a meaningful relationship are still there (of course, I am assuming that there are cues which signal as much).

Just as a thought in conjunction with Niru's comments---so does this mean that some people are genetically pre-disposed to, say, fall in love less or so their attraction to others less? For example, there is the gender issue...I've definitely read plenty of magazine which would indicate that the body languages of men and women differ significantly, but they weren't exactly scientific journals, so it's still questionable to me. If your genetic makeup supports falsifying cues less, can that make you a better driver or better at catching spelling errors?

I have some other questions, but I want to wait and see what this Tuesday's discussion has to say about some of the ones already mentioned before I go on.


Name: Kate Lauber
Username: klauber@haverford.edu
Subject: Perception
Date: Mon Mar 26 20:11:15 EST 2001
Comments:
I've been finding the discussion on blindspots really interesting. While I remember from biopsych they develop from spots where neurons overlap on their pathway to the brain they also give interesting insights into perception. I had an experience a few nights ago where I was dreaming and someone in real life said something to me that was totally seperate from what I was dreaming another person was saying, yet I took them to be the same thing. I woke up and asked my friend if he told me to "move over" on the couch and he said no- he asked me if I wanted to turn the movie off. I superimposed his voice onto what was said in the dream and was convinced he said it. I feel like this stuff happens in movies all the time but it makes you think about conciousness of events and where that conciousness lies. I was aware of my friend's voice and that someone was talking to me, but not of what was said. In the same sense, we are often unaware of our blindspots, in my opinion because we superimpose the rest of the image of what were loooking at over them to accomidate for them. I guess it's a question of what we actually see, or hear, and what we "fill in the gaps" with what we perceive it to be. This discussion has made me think a lot about what actually happens to me, and what I just assume happens through other modalities. I guess blindspots are more complicated than I thought.
Name: Elizabeth Gilbert
Username: egilbert@brynmawr.edu
Subject: lover's eyes and perception
Date: Mon Mar 26 20:36:17 EST 2001
Comments:
I am stuck on this thought of staring into lover's eyes and getting that "feeling" that you seem to trust. I don't believe it. Rather I think that the feeling that Daniel speaks of is really pheremones. There is no I-function but just a bunch of chemicals that create signals that we call perception for lack of a better word.

As for the blind spot, we are not aware of it because it is always there. It is just like the fact that you are not aware that you blink your eyes quite often unless you think about it or do something to be conscious of it. We are not aware of the blind spot because our eyes are moving and scanning the room so anything that is in the blind spot is not in the next moment. Thus, except for small details, our brain can use the memory of previous information to make up for information that is missing. I find it pretty amazing that something so small is so powerful.


Name: PaShawnda
Username: pbriley@brynmawr.edu
Subject: a white room
Date: Mon Mar 26 20:45:40 EST 2001
Comments:
Yes, I admit that I am uncomfortable with the idea that the brain is generating a picture from either memory or a continuous pattern phenomenon to compensate for the eye's blind spot. I think that I would be more comfortable with this idea if we lived in a white room, but there is so much to percieve in life where detail is important. Sometimes seeing every detail is important, like when driving or sewing. I wonder what would happen if everything in the world was painted the same color, shade, tint, etc? From the demo in class, it seems like the brain interprets objects as different things because they reflect different amounts of light. Would the brain perceive the world as one large mass if it was all one color? I know the eye uses other cues to interpret objects, like texture and shape, but they would be dulled if they all reflected the same amount of light in our eye, right? And since these made up parts of our perception is not made up by the I- function, but by the other part of the nervous system- it leads me to question the necessity of the I- function.
Name: Meghan
Username: mshayhor@brynmawr.edu
Subject: seeing and not seeing
Date: Mon Mar 26 20:47:31 EST 2001
Comments:
The ability of the nervous system to fill in the blind spot in intriguing. It seems to be an innate behavior in all of us. It must be something we are born with as the I-function of young children, just like adults, can create things that aren't really there. This does not appear to be an acquired skill of the brain.

I am interested in learning what else the brain "makes up"? How often does this phenomenon occur? I do not think we will ever know the answer because we do not know how much the brain is filling in for us in each thing our perception is telling us we are seeing.

In the examples in class, everyone's I-function was creating the same dot that did not actually appear on the paper. When will one person's I-function make up one thing and my I-function create something else? This must occur as we all can percieve different things when examining the same picture. (like the old lady/young girl figure) I believe that the I-function accounts for each person's uniqueness as it can arbitrarily choose what it wants us to see and not see.


Name: Christine Farrenkopf
Username: cfarrenk@haverford.edu
Subject: the eye
Date: Mon Mar 26 21:17:45 EST 2001
Comments:
I have to agree with everyone else about how strange it is that the brain is able to make up visual information so that there is not a hole in our vision at the blind spot. Previous to this, our understanding has been that the I function is the only element of the nervous system that can "interpret" information. But now, we are seeing that the brain is also able to "interpret" visual signals in that it can create an image where there isn't sensory information. I am very curious as to how the brain accomplishes this feat.

While we were talking about the brain "making up" visual information, I began to think about hallucinations. What exactly is a hallucination in terms of the nervous system? Clearly, there is no sensory input coming into the eye causing such a vision. So where does it come from? And how does it manifest itself on the retina? Is the brain making up information as it does with the blind spot?

Another question I have is how is a "visual image" stored in the brain as a memory? And how can we "see" something while we are asleep and our eyes are closed?


Name: Katerina Sioutis
Username: grkdelfinii
Subject: Why would our brain do this to us?
Date: Mon Mar 26 22:14:29 EST 2001
Comments:
This whole idea of our brain "filling in" our experiences is kind of scary. This means that the world we experience is in many ways a constructed world. After the experiment we did in class with the cross and the dot, I have realized that perception is actually more than just seeing directly but that it also involved some subconscious interpretation. I would like to mention something interesting that I read on the web. The philosopher Daniel Dennet has proposed that the brain often does not fill in our experiences (ie. blind spots). He says that if we don't notice the blind spot, it is because the brain is not actually doing anything with the information from that part of the retina. The region is just being ignored and the brain does not go back to fill in our experience - because we have already jumped to a conclusion of what we saw or experienced. But why would the brain choose to ignore information coming into the retina? Why does the brain "fill in" our experiences in the first place? I found it interesting that when the brain "fills in" our blind spot (artificial scotoma - is that the biological name for it?) we can measure changes in the firing rate of cells in V1 of the visual cortex. We can watch their response pattern change to something close to what it would have been if the pattern was filled and projected onto the retina. I want to know why the brain does this and is it an important function of the brain. Why doesn't the "I" function know about it (I mean I know the wiring aspect but why are we wired that way?)
Name: jenny
Username: jecohen@brynmawr.edu
Subject: more blind spot stuff
Date: Mon Mar 26 22:22:55 EST 2001
Comments:
Okay, so I was at the Guggenheim a couple of days ago and I was looking at one of Lichtenstein's paintings - it had a dog saying "ruff" or "growl" or something like that in front of a field of blue dots. When I looked at the painting, the blue dots looked like they all had white dots in them. Because of this class, I knew the white 'holes' probably weren't really there and when I made myself look at the painting with one eye closed, sure enough I saw solid blue dots. But if I haden't taken this class, I think I might have thought that what I saw at first glance was true or at least have speant a lot more time in figuring it out.

So my question is, because I knew the dots weren't really there but saw them anyway, was I really seeing them or was it a trick of my brain? I mean, I know that each eye sees a seperate field of vision and then our brains put them together so they match. So is this overlapping picture really what we see, or just what we think we see (because in this example the pictures overlapped to form a false immage)? I don't think this is very clear, but I don't know if I can make it more so. Maybe I'm asking for the definition of the word "see" for this class. Is what we see just the light reflections picked up by our eyes, or does that have to be processed, sent, recieved, and interpreted before we are calling it seing?


Name: sarah
Username:
Subject: eyes
Date: Mon Mar 26 22:34:26 EST 2001
Comments:
Eyes are very fascinating things, especially when two of them are working together. I find it interesting that I can focus my eyes on an object and realize that I cannot clearly see the surrounding objects, even though I think I can see them all clearly when I'm not thinking about this. However, even though I know about blindspots I can't make myself see them. I wonder when our brains start filling in these gaps. Does it happen at or before birth, or does it take an amount of time for the brain to adjust to? I am also interested by the fact that filling in the blindspots seems to be automatic for everyone; does anyone know of a situation in which this does not happen? My I-function is curious to know if there are other gaps that my brain is filling in, like certain pitches that I'm convinced I hear or certain sensations I think I feel. It's so weird to know that there are two large spots of this computer screen that I actually can't see...
Name: Irma
Username: iiskanda@brynmawr.edu
Subject: Vision
Date: Mon Mar 26 22:55:09 EST 2001
Comments:
I had actually done this experiment before as a Freshman when Prof. Grobstein gave a lecture on this exact topic in English house to our College Seminar regarding education. It was intersting and never failed to disturb me, how we are probably conscious or aware of a very small percentage, perhaps, of our behavior and how the nervous system works, how our "I function" is only a small part of how we explain our behavior. This experiment reminds me of how people who become blind in one eye eventually start seeing the world as like a flat painting, just how weird things your eyes will do under certain situations.Perception, therefore, seems to have more than the eye can see. There are still situations that we cannot control beyond our "I function", which is a fascinating discovery to make.
Name: Sadie White
Username: siwhite@brynmawr.edu
Subject: I-function: magical or physical?
Date: Mon Mar 26 23:02:42 EST 2001
Comments:
From what we've learned of brain organization and function thus far, it is unsurprising to me that the brain can (and does) "fill in" the perceptual gaps caused by the "blind spot" in the eye caused by the lack of photoreceptors in the portion of the retina through which the optic nerve exits. It seems that, as the course progresses, the I-function strikes me as more a construct of itself than an entity having a clear-cut biological boundary. That may sound unclear, so let me explain. What we "know" of the I-function, is, by the very operative definition of "knowing" that we've been using thus far in the course, rooted in the perceptive powers of the I-function. That is, all that we "know" is limited by what we think that we know, or what our consciousness is aware of. I wonder if we could ever train our I-functions to be aware of a greater scope of reality - or maybe they are forever encapsulated within their current perceptive range, fluid as it may seem when one considers the seemingly boundless expanse of human creativity. That, of course, poses endless philosophical questions regarding the existence and validity of imagination, feeling, and all that our I-functions do that are not strictly functions of the processing of their surroundings. However, perhaps it could be argued that all imagination and creativity are merely recombinations of the veritably infinite permutations of the input our I-function receives every moment. Often the questions that I find myself asking seem to be mere I-function acrobatics, or the philosophical equivalent of holding a mirror before a mirror like a curious child, creating an endless tunnel of reflection.
Name: Nana
Username: ndawsona@brynmawr.edu
Subject: What Am I not Seeing?
Date: Mon Mar 26 23:55:46 EST 2001
Comments:
The idea of blindspots is absolutely fascinating to me. Performing those little tests raised many questions for me, most pressing "what else am I not seeing?" If it is possible to miss a space as large as that spot, what other things is my brain just filling in? How people develop their I-Functions, shape their personalities does depend to a large degree on external stimuli. We usually trust what our eyes tell us, but now knowing that is not always possible is disturbing. I wonder how differently my I-function would be if my brain actually reported exactly what my eyes saw. I'm sure that it would not be that different, but it is still an interesting question to ponder.
Name: Nazia
Username: nahmed@brynmawr.edu
Subject: blindspot
Date: Tue Mar 27 01:05:14 EST 2001
Comments:
The blindspot and how the brain "makes up" for the inability of the eye perception is fascinating. If the brain tends to make up a picture or pattern for a viewing area called blind spot, then this might imply that these certain patterns are "saved." Each time they are needed they are accessed by certain inputs or the absence of input as in the case of the eye where there are no neurons in the retina to absorb a photon. Basically, a certain pattern of neural behavior is turned on, and the brain either repeats a certain visual pattern that the other neurons in the retina input information about, or it applies a visual image that had been saved from a previous event. This would surely account for blind-spots in visual perception.

I had actually heard of studies where it was thought that imagination enhances our ability to see what's really there. The example they used was that it was easier to identify a friend in a crowd when he actually appears. From this it makes sense that blind-spots are perhaps pre-stored patterns or ďimages.Ē


Name: NJ
Username: sophisticatedivy@hotmail.com
Subject:
Date: Tue Mar 27 01:59:48 EST 2001
Comments:
I don't know about the rest of you, but I am perplexed by the idea that my brain is making up objects that "I" necessarily cannot see. Until taking this class I have never thought of the brain as being as creative or intelligent as it is. I initially took this class only as a means of achieving a natural science credit and due to interest. However, I find myself enjoying the class a great deal and instead of the class being a mere requirement, I am involved moreso because of I am interested. I am learning so and my brain is being stimulated in new ways. That is what tis important to me. Not that I just receive a natural science credit.
Name: karen munoz
Username: kmunoz@haverford.edu
Subject: just us?
Date: Tue Mar 27 02:16:35 EST 2001
Comments:
i think avis' point about the evolutionary purpose of filling in the blanks is very interesting. it is hard to imagine what it would look like if we just saw blank spaces instead of filling them in. and like most people i'm curious what role the "I-function" plays in this process. do other animals have the blind spot as well? that is, is their eye set up in the same way as ours that the blind spot would occur, and does their brain compensate in the same manner? i'm just interested in why we compensate for the blind spot, if it is merely so that we do not get distracted by gaps in our vision.
Name: karen munoz
Username: kmunoz@haverford.edu
Subject: just us?
Date: Tue Mar 27 02:16:40 EST 2001
Comments:
i think avis' point about the evolutionary purpose of filling in the blanks is very interesting. it is hard to imagine what it would look like if we just saw blank spaces instead of filling them in. and like most people i'm curious what role the "I-function" plays in this process. do other animals have the blind spot as well? that is, is their eye set up in the same way as ours that the blind spot would occur, and does their brain compensate in the same manner? i'm just interested in why we compensate for the blind spot, if it is merely so that we do not get distracted by gaps in our vision.
Name: Caitlin Costello
Username: ccostell@haverford.edu
Subject:
Date: Tue Mar 27 02:58:15 EST 2001
Comments:
I was thinking about dreams, and of how they seem to be another way of the brain filling in parts of our experiences that the "I" cannot perceive. I have had a few dreams that have quite accurately (and eerily) predicted the future, for instance specific things people later said or did. I think this might happen because my brain has been able to pick up cues from other people or my environment that were too subtle for my I-function to perceive as they were happening, because the "I" has too many other things to be concerned with in our waking hours. Yet the brain is able to record and store them somehow, and then later when I am asleep and not inundated with sensory input, my brain can use these cues to make pretty good inferences about people's future behavior, thus "predicting the future." And because these predictions involve processing aspects of myself and how they relate to others and my relationships with them, this seems to necessitate the I-function. And it's weird to think about the possibility of my I-function at work while I am asleep.
Name: Claire
Username: cwalker@brynmawr.edu
Subject: The Blindspot
Date: Tue Mar 27 07:29:51 EST 2001
Comments:
This whole discussion of the blindspot is very interesting. I took the eye test earlier in the year and the test that I found the most interesting was when there was a more complicated pattern of lines and colors and your eye still can make up the pattern that should be expressed in the blindspot. The mention of blindspots when driving is particularly interesting because that is really a big part of learning how to drive. Especially perceiving distance and weather conditions can be really scary for a new driver. I think it has alot to do with how you learned to drive. For example when I was learning how to drive I took a drivers ed course and it was like baptism by fire. The traffic conditions and weather conditions that I had to drive in made me very comfortable in most driving situations. It usually doesn't bother me if I can't see so well because of fog or rain.

This idea of a blindspot had me thinking about horses. I have watched programs on how the eye of the horse works and it seems that the blindspot that they have to deal with much more difficult. The fact that they can't see something when it is right in front of them (like a jump). When you approach a jump the horse can see an image of the jump in each eye and then as you get closer the images start to come together, but then about 1 stride away from the jump, the horse can no longer see it and relies on memory and the rider, to determine when to jump and how high to pick up his feet. Everytime I think about it it makes me think even how more amazing animals are.

Of course their eyes evolved differently than our own because of their need to be able to see around them for predators. This way with just a slight turn of the head they can see behind themselves, very important for survival.


Name: Mary
Username: mferrell@brynmawr.edu
Subject: Vision as a computer
Date: Tue Mar 27 09:15:11 EST 2001
Comments:
Photoreceptors account for 70% of all sensory receptors in the body, underscoring the importance of the eyes for us while sensing our environment. It is not surprising to me that our eyes would have such inventions such as filling in for the blind spot, in order to perceive as accurately as possible despite the lack of photoreceptors in the optic nerve opening. Seems like a highly evolved computer (since the earliest bilateral animals), regulated by genetic mechanisms; bioelectrical signals that aid in our necessary perception of the world. Our lowly human made computers also help us to fill in the blanks when they complete web addreses or E-mail adresses based on the internal memory. Even spell and grammar check gently coax us into seeing more supposingly proper patterns.

This blind spot "fill in" brings the human machine to a level of what it is--fascinatingly complex but not complete; just doing what it can to survive.

What could be in our environment that we have not developed bioelectrical skills to perceive. Our eyesight only catches a certain speed of image. What might be flashing in our world at a faster rate than we can see and does this have any subliminal effect on us?


Name: mahnoor
Username: mahmed@brynmawr.edu
Subject: blind spot
Date: Tue Mar 27 21:31:04 EST 2001
Comments:
The discussion regarding blind spots and the brain "making up" images conveniently, was quite interesting and a little perplexing. We started this conversation off with a consideration of why evolution works the way it does. I'm curious as to whether this feature of the retina is present in only humans or all animals, or in some species only?




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