Week 8 - Neurobiology and Behavior

Paul Grobstein's picture

So, we've made it to the sensory side of the nervous system.  And discovered, among other things, that the nervous system isn't organized to give one a picture of "reality."  Thoughts about that, or whatever else has interested you this week?

James Damascus's picture

Am I really seeing that apple?

think the philosophical paradox holds true for any system of representation (metaphor, drawing, language). This is the issue taken up with epistemology, and, to some extent, why hermeneutics becomes a more attractive paradigm. What we 'see' in response to light waves is an image generated by a series of coordinated action potentials in our heads. Since the neuronal wiring in our brains is very similar from one human to another, it seems logical to me that we should each see an apple when processing similar inputs from our retina through the optic nerve to our brain. Certainly the information we store about apples (what apples taste, smell like, where they're nutritious foodsources etc.) is certainly influenced by experience (or, sticking with Emily Dickenson, changes to our neurons resulting from experiences and learning), although I would think most human brains would 'see' the same shape, colour etc. when viewing an apple, irrespective of acculturation. 

JaymElaine's picture

My Individual Visual Perception

After today's class, 03/20/07, I was stumped...as usual for this class. We talked about vision and individual visual perception. So let's see here, if I see an apple, I know that it is an apple because I was taught as a child that an object with those dimensions, that size and color, and smell is consistent with an apple. But am I really looking at an apple? My brain could be playing tricks on me. My brain is merely making sense of the sensory input coming in through my eyes and nose. My friend comes along and sees the same object; has she also processed it to be an apple? And if so, did she process that in the same way that I just did? Is the apple really an apple, or is it an apple because my brain said that it was? What if it really something else? Or, again, I could really just be thinking into this just a bit too much!

Jayme E. Hopkins, '08

Meera Seth's picture


Although somewhat old hat by now, I find Malcolm Gladwell's book "Blink" to be particularly relevant to our discussion concerning vision. The premise of his argument is centered around the idea of an intuitive reaction to a certain (visual) stimulus. He makes three solid examples: a curator or art historian views a statue and immediately recognizes the piece as a fake; a tennis coach witnesses a player toss up a ball and from this directly knows that the ball will hit the net; and finally the most astonishing, a behavorial expert is privy to a couple's brief interaction and from this encounter can determine if the couple will divorce eventually.

Gladwell contends, "The power of knowing, in the first two seconds, is not a gift magically given to a fortunate few. It is an ability we can all build for ourselves."

Evidently, the link between one's vision, mind, and resulting "judgment" (if one can even call it that; perhaps more accurately termed "reflex") is incredibly strong. This raises several interesting questions, namely, if one makes decisions and judgment calls without any real reflection, how does free thought and free will function in our consciousness? Can we do anything to exert more control over our mind's processes? Are we really in the so-called driver's seat? Or are we merely passengers?

Shayna or Sheness Israel's picture

When You Look into A Mirror Are Your Seeing 2-D or 3-D?

I found this interesting question on Help.com, "When you look into a mirror are you seeing 2-D or 3-D?"

At first I thought this question was super hard. Then someone else on help.com who responded to her said, "Well, when you look at the television, you have depth perception, so why is the mirror any different?"

That was such an illuminating answer and connection. That kid was right; in the mirror we do perceive objects in varying depths.

So my question is how does our brain work to create depth on a 2-D plain like a drawing on a piece of paper?

Another thing that intrigued me about what we learned this past week is that we do not have conscious control over not seeing these blind spots. Personally, I don't really mind that I don't. Knowing that I do is enough for me. It is another thing that lets me know I do not know the world or reality objectively.

Sasha's picture

drugs and vision

At the end of our last class our understanding of reality was questioned because of the existence of our blind spot. This led me to wonder what happens when someone chooses to actually use a hallucinogen and chemically distort their ability to understand and interact with reality. Some effects seem to be an inability to understand the passage of time or to understand that objects and people around you are real. In general it seems to cause your brain to interpret visual images and the world around you differently.

            Some explanations for the effect of hallucinogens on the brain are that hallucinogens have similar structures to serotonin. They disrupt the interaction of nerve cells and the neurotransmitter serotonin. Serotonin is distributed throughout the brain and is involved in the control of many systems including behavioral, perceptual, and regulatory systems. Understanding that the distortion of the serotonin system will have huge effects on the brain, I still do not entirely understand how ones ability to see things normally is distorted. What are the exact neurological effects of serotonin on the “perceptual” system and how do hallucinogens change what is going on? Does something happen to the images that you see- once the images reach your brain is your brain unable to process them as it normally would? If that is what is happening could it also be interpreted that vision has an effect on how we interpret time, since ones sense of time is also distorted when “tripping”?



Ian Morton's picture

light in its importance for knowledge of reality

We’ve begun to address the concept of an image in the mind.  Vision involves the conversion of light into nerve pulses on the retina, which broadcast a perceived image of the outside world to our conscious and unconscious Mind.  This creates a multi-dimensional representation of the world, which we interpret as our reality, the physical world we are apart of.  While the pathway of light progressing into a representation of our reality leaves much to be questioned about how our interpretation of the world compares to objective reality, I think it is also important to just consider vision’s roll in grounding ourselves in a physical world that constitutes our reality.  The other senses certainly play an important roll as well, but it seems that vision is the sense we value most for its roll in illuminating knowledge of our reality.  (You might have a personal preference for hearing, perhaps you’re a musician, or taste, but seeing is almost synonymous with Knowledge -- God sees all, Big Brother is watching you, the all-seeing eye on the Masonic seal of America. etc.)  So what happens to our reality in the dark?  If there is no light to be translated into an internal model of reality, what does our reality become?  If you sat 40 feet down in the ground, at the bottom of a well, with no light penetrating deep enough to reach your eye, what happens to your perception of your body and the physical world? (á la The Wind-Up Bird Chronicle) Certainly this is a question that has been considered before, and I think it would be interesting to investigate some previous insights into the importance of light for the creation of reality.

jpena's picture


As demonstrated in class last Thursday, there is a blind spot in our retina. We found it by using the cross and the dot on a sheet of paper. But when we could no longer see the dot we did not see a hole or blank spot, instead we saw white. Immediately I thought about whether or not this qualified as a hallucination. I know I saw something that wasn't there. This must mean I am always seeing something that isn't there. Standing outside a building I might see a wall where there is really a window only because the window is in my blind spot and is surrounded by the brick wall, which I can see. As far as I know I have never hallucinated to any extent larger than my blind spot(s). But if the human brain is capable of generating and perceiving mental images without receiving input then I have to start questioning reality in terms of what I am seeing. Can I really trust my brain to give me an accurate image of what is in front of me?

urbrainondrugs's picture

Blind Areas

Extra sensory input is an amazing concept. On thursday we learned that we acquire information without even being aware of it. Just as proprioceptors, without our conscious knowledge, receive and process information about the states of our muscles and tendons to manage movement, we receive information from objects around us and our nervous system manages it without our consciously deciding what to "see" and what not to. We illustrated this with the blind spot experiment. 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 basically invents an image which it believes would normally be there. It is capable of making us perceive images differently than what they really are! This is an interesting and a little scary concept. (Crazy people are not alone, apparently we ALL invent images and see things that aren't really there.)

This got me thinking. What if we have blind spots in all of our extra sensory perceptions? Is our nervous system filling in other black areas in, say taste? or smell? Could we be tasting and smelling things that are not present? Perhaps the universal filler of the taste "blind spot" is the taste of chicken.

biophile's picture

Perception of objects... What is reality?

Although many have already registered their fascination with the last lecture already, I'd might as well throw my hat into the ring. Last class was particularly interesting because we melded mechanics with philosophy. I enjoy philosophical, abstract conversations as much as the next person but it is nice to have something more solid to grapple with. We've been learning about the biology behind nervous systems and applying that to philosophical issues quite a bit in this course; however, it's easy to lose sight of the actual biological mechanisms underlying the problems we've been discussing. This topic of visual perception and eye anatomy is so fascinating because it lets us see the man behind the curtain. We now know in what ways the very structure of our eyes limits us in perceiving reality.

The idea that we can perceive things by way of registering points of reflected light is a simple one, yet it's an idea I've always had trouble articulating. I would think about it a lot as a child when I was trying to figure out just what reality was. I couldn't figure out what it was that I was perceiving. Without anyone telling me, I intuitively felt that the world I saw around me might not be the world as it truly is, that my vision was dictated by the physical structures that enabled me to see (talk about catch-22). This issue seems especially pertinent when dealing with art. Who else has been frustrated when trying to draw from a certain perspective or trying to shade just so? The same thing goes for 3D computer modeling. How do we represent reality realistically? What cues us that one object is facing away a few degrees as opposed to straight on? How can we really tell the difference between an object and the background? It's not as if we're cartoon characters with thick, black outlines after all. It's hard to convey even these ideas, since they're taken for granted in day to day life. But if we consciously think about it, it becomes clear that a lot is going on here.

In any case, it's comforting (although I guess for others it's disconcerting) to know that certain quirks in the human visual system can be explained by basic physical principles.

katherine's picture

learning to see

This week's discussion about vision and our perception of what we see vesus reality was really interesting to me.  Although our discussion was about how we are able to see, it made me think a lot about what it would be like if I wasn't able to see.  The ability to see is something that the vast majority of us are born with.  I don't know about anyone else, but I don't remember life as an infant.  Was I able to see as well then as I am now?  Or was it something that I had to learn and was perfected later?  Do we have to train ourselves to fill in the holes that technically should be in our vision?  If someone is born blind or with limited vision, are they able to somehow gain the ability to see later?

clin's picture

Sensing things

How does one explain intuitions? Why is it sometimes when an incident occurs a person will say, " i knew that was coming" or " i had an inkling something like that was goign to happen" Is this intuition a legit process of the brain's sensory system or is it just a phenomenon that we can't explain? The book Blink delves into " thin-slicing", and it got me to think that maybe all this intuition feelings are just daily thin slicing that people have accustomed themselves to but are just unaware. How much of what we sense is actually psychological or really a sixth sense?

alexa09's picture



If intuition is defined as one guessing another person’s decisions, then intuition can be explained by the brain. The brain can analyze different factors and come to a reasonable conclusion on what the person will decide. It is possible for the analysis to done subconsciously and therefore it is as if someone is “intuitively” coming to a conclusion. However I am not dismissing the possibility that there is something like a seventh sense (seventh b/c we have 5 senses- smell, tough, sight, taste, hearing, orientation in space aka proprioception). How do we explain when parents sense there is something wrong with their child and call them to check on them to find something indeed has happened?

Caroline Wright's picture

Illusory Color

Before we returned from spring break and began looking at the sensory side of the nervous system and vision, I read a very interesting article called “Illusory Color & the Brain.” The article talk about how the role of color for most people seems to be to illustrate what we see in everyday life. However, color is merely a perception in the brain. In fact, when it comes down to it, while color does help us differentiate between objects, the part of the brain that deals movement and navigation is essentially color-blind. With this in mind, it seems that color has much less role in defining form and depth that one might have thought. But then there is the study of illusory colors – colors that the brain is “tricked” into seeing, much like we discussed in class. As has been mentioned, the basics of visual perception are that photons are absorbed by rods/cons in the retina, transmitting a signal through neurons to ganglion cells in the retina. Contrast – and thus the detection of edges - in our vision is created when ganglion cells fire maximally when their center is lighter (for an on ganglion) or darker (for an off ganglion) than its surroundings. This part of perception has little to do with color. However, in visual experiments researchers found that the visual cortex in the brain might respond to the direction of borders when color is involved. I couldn’t find a good image of it, but the example they used were two thin, jaggedy, red lines roughly shaped like the Italian peninsula. In on of them there was second, orange border on the inside of the shape, and on one an orange border on the outside. In the shape with the orange in the inside, the shape seemed to be a little elevated off the page and the color seems to spread throughout the empty space in the middle. The shape with the orange on the outside made the shape seem repressed into the page. Researches think that a possible explanation for this is that neurons respond to a certain type of contour when there is a lighter color against a darker color, or visa versa. They give a lot more examples of these visual illusion tricks, but seeing as that last one was hard to describe and probably made no sense you can find the article in the March 2007 issue of Scientific American. Basically, there is a separation in the brain between color and basic visual perception, but in both cases the brain can create illusions of things that aren’t really there, sometimes even combining the two.



AriannahM's picture

Is that REALLY green?

One of the amazing things about being a human is that we are able to realize the many ways that we are different. The way we see is just another. I was not surprised that the picture we see in our brains is “bigger” than the picture on our retinas. I agree with Sarah Harding…isn’t this perfectly logical? I was also intrigued by a similiar question as Sarah posed. I have always been curious about perception of color. What if the color I see for “green” is different than the color everyone else sees for green? If all my colors had always been different then the adjectives used to describe them would always be different too right? This concept has always boggled my mind because I don’t know of any way to prove that it can’t happen. Any ideas?

Sarah Harding's picture

Wider than your retina

It was "revealed" to us last class that the picture in our heads is larger than the picture on our retinas... Shouldn't we have already known that? Our eyes are so small, and our brains are supposedly "wider than the sky," so it shouldn't be difficult for us to comprehend that the retina picture is smaller. However, it's uncomfortable to know that picture transmission from retina to brain is done completely without the I-function. Other students have brought up the issue of reality on this blog. If our percieved vision is transposed without our knowledge, then our perception of reality could be skewed without our realization. Perhaps we are seeing the world through rose-colored lenses...or something of the sort. The scientific explanation is that our eyes are always moving, and the brain pieces together the small images from the retina. While I'm walking around, however, I don't feel my eyes rapidly scanning, or my brain piecing together myriad images. This is done so quickly, and without consciousness. That's incredible. On the contrary, it's frightening to continually realize the actions that are perfomed without conscious effort. I don't necessarily believe that what we are seeing isn't reality. To us, at least, it is reality....and that's really all that we need to know. However, I do think it's interesting that we could all be percieving the world differently. If one person's eyes don't move as rapidy as another persons, is their vision imperfect? Is it perhaps less sharp, less detailed, missing pieces, etc...? How fascinating the topic of vision is....

Lauren Poon's picture


In class, we agreed that experiences are psychosomatic so activity in the nervous system leads to the senses. What happens when a child closes his/her eyes when getting a shot at the doctor’s office? Why do people claim that the shot will hurt less if you close your eyes and not look at the shot? Nothing different happens to the nervous system in relaying signals to the brain, only the eyes close which happens after. We claim that the nervous system fires first and then the eyes see. The child should feel pain despite whether or not the eyes are closed.

Alex Hansen's picture

Brain Damage

I was just looking through the news aggregator and I came across a rather interesting title of an article so I thought I would read further, and I was very intrigued by this subject. The article is titled "Brain Injury Said to Affect Moral Choices" located in the science section of the New York Times.

The area of the brain associated with this described damage is the ventromedial prefrontal cortex and is located behind the forehead, more specifically a few inches behind the eyes. The prefrontal cortex is general involved with short-term memory and damage to this prefrontal cortex can cause short-term memory deficits. Furthermore, it has been said to be associated with higher cognitive functions such as language, abstract reasoning, problem solving, social interactions, and planning. Therefore, when I read: "Damage to an area of the brain transforms the way people make moral judgments in life-or-death situations. In a new study, people with this rare injury expressed increased willingness to kill or harm another person if doing so would save others’ lives" I tied it back to the cognitive functions listed above and it seemed to make complete sense. If there is damage to the prefrontal cortex, then the individual might experience difficulties and deficits when it comes to abstract reasoning, problem solving, social interactions, etc, all of which can be involved with making moral decisions. However, it does seem a bit extremem to just let an infant suffocate and endorse death/killings in high conflict situations. It's interesting how individuals with this damage to their brain resort to violent efforts in crisis situations. I started to wonder about the environmental role in these situations. Does the individual's instruction throughout his or her childhood and further development based on the environment in which he or she was raised have any affect on the moral choice these brain damaged individual's seem to make? Do those prior teachings just become erased from the brain? Are they considered short term memories since the prefrontal cortex is associated with short term memory?

Additionally, I began to think about the military a bit, especially when I read one quote from a patient of the doctor that stated: "Jeez, I’ve turned into a killer." I began to wonder if there is any connection between the individuals in the military who are instructed to kill and preform often ruthless tactics to kill people at times and the brain damage to the ventromedial prefrontal cortex. It might be interesting to extend this study into the military forces to investigate if maybe there is a certain type of person, a certain type of brain that is geared for the military.

Also, it seems as if these brain damaged individuals sacrifice lived without question at time, but what happens when their own lives are at stake? Does the damage to the ventromedial prefrontal cortex change any moral judgement in relation to that individual or is it applied to more external forces, people other than that individual. It would be interesting to really examine the emotions involved here since the prefrontal cortex is said to be involved with giving rise to social emotions. However, what are truly social emotions and how are they all subdivided? Are some emotions hindered while others are enhanced? What is the connection between all of these? It's just really interesting that judgement can be controlled and altered by brain damage regardless of how the individual was brought up.

If anyone wants to read this article, the link is right below:


Alex Hansen's picture

A little follow up...

Sorry, I just had a few more thoughts. I was wondering if maybe damage to the ventromedial prefrontal cortex made humans more similar to animals. I didn't know if maybe the brain more closely resembled a less developed animal brain, or if now the humans had more animalistic qualities, more animalistic judgements and that is why they were more easily inclined to kill.

Also, there was a part of the article talking about court cases and the courtroom, and I was just thinking about if damage to this part of the brain can cause temporary insanity or permanent insanity. Are there other damages as well that might also cause these classifications in the courtroom?

Holly Stewart's picture

Reality as a Convergence Theory

It all started in with the eyes. Our discussion this week about vision as a model for how the sensory side of the nervous system works has proved to be nothing less than troublesome. So a recap: we have this fabulous little sensory organ called the eye. Two eyes work together in a pair, responding to changes in light which cause permeability changes thus causing action potentials. The eyes are able to conceal each one’s discrepancies (i.e. the “blind spot”) and depend on the brain for interpretation of what is perceived. The “facts” about what is “actually happening” is fine…well, sort of. Okay, none of this is really fine for me, and let me explain why:

We see the world as it is, right? More appropriately, the world appears to us the way we see it. There are some fundamental difficulties (for me) about the way we “see” reality. The way we see reality is subject to a large amount of mutation. We receive an input through changes in light and these changes are compiled as many point sources of light, but this light can be misleading. Everything needs to operate correctly, or else the point sources of light aren’t added up correctly on the retina and the image may not appear to be what it actually is. Another complication is that the image that is projected on your retina is upside down and backward – the brain has to do a lot of twisting and turning to make things appear to you as they actually are. And then there is the fact the image is a lot bigger than what gets onto your retina, so the image has to shrink and then be put back together; this leads into the fact that your eyes are always moving and re-evaluating and adding up pictures and changing their interpretation of reality. The reality you get, or the picture that finally is your experience, has been accomplished through a significant amount of mutation, changes and guessing. With this system how are we to even feel confident that we are accessing the “right” reality since the system of our eyes seem to operate on the principal that the reality we see is constantly being altered and changed depending on your position, etc.? Thus, if there are problems about the way we see reality, and seeing is a model for how the sensory side of the nervous system works, then for me, there are difficulties with this system.

We know there are very few sensory neurons relative to the number of neurons in the body. Why is this true? Is there are reason that we don’t have a richer amount of input? (This question is operating under the assumption that more neurons equal a richer experience, which seems logical—although possibly incorrect—conclusion) Has the sensory experience of humans altered over time? What would your experience of reality be like if you had a larger proportion of sensory neurons? I think the reality that we experience is something that we agree on and this consensus is innate in what it means to be a part of Homo sapiens. I think then it is essential to recognize how our reality is shaped by our sensory system.

If the human design is a conserved process then it seems that our sensory experience also follows from a conserved process. The reality which we see and the reality which we participate in may be the same, but they also may be limited. It seems to me that we are participating in a convergent type of reality—we have similar sensory experiences and because of our conserved design and development we have a certain type of experience. In my opinion, if we were able to amplify our sensory experience, we may be able to access a very different type of reality. I think it is safe to say that our “reality” may not be the only thing out there, but it is the only thing that we have access to. Kant also said this, but I want to go beyond and say that the reality we experienced is because of a convergence theory of what is appropriate for our sensory systems. Maybe the reality we experience is a product of what we can handle; or what our brains can interpret; or what our nervous system can respond to. It may in fact be the sensory system that has dictated our experiences within reality.

michelle's picture

Look with your Brain

I think seeing is a ridiculously amazing and efficient process. However, I now realize that we really don’t see with our eyes, but with our brains. To Holly’s post regarding the reason why we don’t have a lot of sensory neurons, I think it’s because we don’t need them. Our brain and nervous system is able to perceive our outside world rather accurately with the limited sensory neurons we do have. All it needs is a simple upside-down, miniature, 2-D captured photo, and the nervous system’s corollary discharge signals, central pattern generators and action potentials can do the job. Also, in response to eshuester’s post regarding reality, I think reality exists despite what we perceive. If we think our eyes are deceiving us, our other senses can verify the existence of things that make up our reality. Also, other people with their senses can verify it.

An example of where our brains do the seeing, but others help us verify reality occurs with anorexia. My sister who suffered from the disease for a long time used to ask me what she looked like when she would look at herself in the mirror. She swore to me at 96 lbs. she could see her belly hanging over her shorts in the mirror. I learned that a lot of anorexic patients will see physically different things in a mirror than what other people see. Although recovered, she’ll ask me if I can tell her what she looks like because she’s still unsure if her brain is still processing her reflection falsely.

Reality goes on without us. Other people and organisms can perceive reality and verify it exists at times when we are incapable of perceiving it or perceive it incorrectly. Emily Dickenson’s poem claiming that the brain contains everything is not completely accurate. One brain cannot contain another brain. Although it can control one’s perception of the world and their behavior, and the world only exists because of the brain, someone else’s brain can contain a world completely different. Therefore reality is comprised of everyone’s joint perceptions of it.

Sarah Powers's picture

What am I looking at?

I went back to my psychology book from the course Behavioral Neuroscience, "Physiology of Behavoir" by Carlson, and looked at the chapter on vision.  At the start of each chapter there is a description of a particualr case study.  For this chapter, Mrs. R was the patient.  She had suffered a stroke that affected her vision.  She could not identify objects, but could describe the object by it parts.  (A wristwatch was put in front of her, she knew it was a circle with two things attached at the top and bottom, but couldn't come up with the word, 'watch.')  As soon as she picks up an object and feels it, she can identify it.  She can only identify people by the sounds of their voice and the way they walk, not their faces.The sensory receptors in Mrs. R's ears (hearing) and hands (touch) obviously still are completely in tact, but one step of communication between her eyes and her brain is broken.  There must be multiple levels of processing to interpret the picture on the retina of the eye.  Looking at the case of Mrs. R. there must be at least one level to identify the parts of an object, and another to put a name and function to the object.  There is probably another whole section that processes movement and putting names and functions to those movements (this pathway seems to be unaffected in Mrs. R.)Recognizing what you see is not a simple process; there are different levels of processing and different pathways.  It will be interesting to see in the upcoming lectures to see how our brains can make a comprehensible picture entirely different from the image on the retina.  The brain must play tricks on us.  The picture in our head is really only nominally related to the picture in on our eyes. Going a step further, the picture I have in my brain, and the picture in yours must be really different purely based on the fact that the initial image must go through many steps in processing.  And when there are a lot of steps, there's a lot of room for differences from person to person.What do you see?

Pleiades's picture

Heights, Fear and the I-function

Holly’s post last week made me start thinking about being scared of heights and general fear and the I-functions role. It brought me back to one day when I was scuba diving in Costa Rica. We were diving on the edge of an underwater canyon and as I swam over and saw the drop of, I panicked. I thought I was going to fall (keep in mind I was floating. There was no more chance that I would go down, as float up)!! Now normally I have minimal fear of heights, but I saw the bottom drop out and I got an overwhelming, totally irrational wave of panic. After I told myself that I was in the water and could not actually fall down into the canyon I was fine and the panic dissipated. For me most fear is something that can be rationalized and it takes it away, but for some people fear is totally debilitating and cannot be rationalized. What is it about my I-function that makes it able to overcome my unconscious (and irrational) fear where as other people can’t? This brings me to the question what is fear? For me it was probably a wave of adrenaline triggered by my brain but what caused it? And why was my mind (read I-Function) able to stop its production. Just a few questions to dwell on.

secaldwe's picture

Synesthetic Much?

I always thought my unique word associations were testament to my being an English Major and a writer. I had only ever heard of the word "synesthesia" in an English course talking about cross-sensory metaphors. The root of the word is Greek meaning roughly “union of sensation” and until last week’s Neurobiology and Behavior course, I had never in my life considered my personal habits to be a neurological symptom of a condition. After further reading I discovered that most synesthetics are never formally diagnosed because their thinking isn’t wrong or weird to them and thus no cause for alarm. There is a distinction to be drawn between genetic synesthetics and event related causes. For example, if I had dropped a lot of acid in the 60’s, there would be good reason for me to associate colors with numbers and tastes with words. Stroke survivors and others involved in traumatic events often report synesthetic responses.

I am intrigued by the behavioral differences between synesthetics and non-synesthetics in life and in the rest of the nervous system. How is someone who associates – no joke – the word “choose” with the taste and smell of french toast wired differently than the person next to her in class? Has it made a major difference in my life? Is that why I am inherently creative because I cannot conceive of thinking differently? This condition is fascinating and I wonder just how prevalent it is.

leigh urbschat's picture

Synesthetic Much? Response

Just thought I should respond with some more information on synesthes, as it was what I wrote my first web paper on (check out the bibliography for some more books and web articles on the subject). Originally, scientists believed that synesthesia was indeed a cross wiring between areas of the brain that do not occur within the brains of non-synesthes. The areas of our brain that deal with color and also number processing are in very close proximity and, in fact, both utilize a part of the brain called the fusiform gyrus in the temporal lobe. In other words, this theory made sense. More recently, however, there have been connections made that incorporate chemical imbalances that may be responsible for synesthesia (as of now I do not believe there is a definitive explanation for synesthesia).

One of the most interesting explanations I found, however, is that all babies are born as synesthetes, otherwise called the Neonatal Synesthesia Hypothesis. If all babies are born without the ability to distinguish between the senses than what is it that causes one person to keep those connections, while another does not? Synesthesia has been determined to be genetic, but does this mean that there is some evolutionary benefit (it is a dominant genetic condition passed along the x chromosome) that has kept it prevalent within the gene pool (an estimated 1:25,000 people has the condition, probably more as you yourself were unaware of your synesthete status)? I too find this to be a very interesting condition and also would like to know how it makes a difference in some peoples' lives.

LS's picture

Sensory Cooperation

Yesterday, I had to spend all day driving to Connecticut to pick up my car and while driving back I was contemplating vision and what I was seeing and what my brain was “filling in.”  It amazed me to think that the other cars, the road, my steering wheel, everything was a just points of light, two dimension images on my retina that appeared to me as three dimensional images.  Now I am wondering where my blind spots are and as I maneuver around my world try to image all of the possibilities that are available with this.  I know that we are only studying the vision sensory system but this has made me realize that all sensory systems must be working together.  Obviously corollary discharge and photoreceptors are coming into play just I never realized the extent to which they are.  If our brain is effectively filling in blank spots it must communicate with our sense of touch so that if we feel something our brain must signal to us that we see it.  The same must be true with hearing and smell.  If we see a door slam out of the corner of our eye that we must hear the sound too.  Perhaps illusions (like magical illusions) or hallucinations are signals that our brain is sending to our eyes “we see this image” but our sense of touch is not keeping up that’s why we can pass our hand through the image and not feel anything.  I am beginning to think that perhaps many forms of psychosis can be explained this way.  If the corollary discharge in a individuals is not regulated properly they may hear and see things that are not there such as in schizophrenia, is their brain effectively making up bad “fill-ins?”  Just curious if anyone can think of any other disorders that may be the result of this sensory system make up.

Rebecca Pisciotta's picture

Visual Agnosia

I think an interesting and useful way to think about vision is as a hypothesis. We see a hypothesis of how the world should be. This is why when we walk into our rooms we do not have to look for our alarm clock and we are not surprised when we see a small black cube in our peripheral vision. Our brain has formed a hypothesis of how our room is to look. If there were a tiger in the middle of our room we would indeed be surprised, we did not expect to see that. I think this is a useful way to think about vision because it accounts for the perceived ease of seeing. If we walk into an office expecting it to be a certain way we need not give thought to everything that occurs in our visual field. This makes sense evolutionarily as well. It is crutial for survival that we not be overloaded by giving attention to everything we sense at all times. I am not saying that all we see is this hypothesis. We of course analyze the visual stimuli we receive, and especially the aspects that do not fit into our hypothesis (the tiger).

So there must be an interaction between various mechanisms here. One mechanism forms a hypothesis of the world, based on what we know and expect. One mechanism perceives and analyzes the actual stimuli on the retina. And a third checks how they match up, and pays special attention to where they do not.

An interesting disorder that may result from these mechanisms not functioning correctly is visual agnosia. Oliver Sacks wrote about a man who lost his sight at 2 years of age but was able to have it restored when he was around 50. He had lived his whole life as a blind man. When his vision was restored he had visual agnosia, he could not make sense of what he saw, he was able to see shapes and colors, but not identify them as objects. When he first woke up after surgery he said he could here voices, and see pink circles but was not able to make a connection between the shapes and them being faces.

Maybe this resulted from a problem with his hypothesis forming, and stimuli checking. Since he had lived his life as a blind man his hypothesis of the world was rooted in his remaining senses. His hypothesis of what to expect when walking into his bedroom might have involved the smell of it, how his footsteps would sound, and where he could expect objects to be. So when he was able to see again it proved difficult for him to integrate the shapes he saw with his hypothesis of sounds and smells. He was not able to form a visual hypothesis of the world, and was therefore confused, equally, by all stimuli.

I wonder how far our hypothesis about the world extend. I would be surprised to walk into the dining room and have them serve me a plate full of dirt, I would also be surprised if i ate a grilled cheese and it tasted like steak. How much of what we perceive is first hypothesized about? How much of perception do we miss out on because it doesnt meaningfully contradict our hypothesis?

eshuster's picture

If we can't see reality, does it exist?

In class we discussed how we don’t really see what is actually there. We have areas in the eye that do not have photoreceptors and the areas that do have photoreceptors are organized in a way that makes no sense. If these photoreceptors enable us to see what they have the ability to see (2-d) how do we know something is 3-dimensional? I can’t understand how we think we are seeing reality but we are actually just seeing 2 dimensional images with blind spots that lie make us think we are seeing reality? But my question is, What is reality? And, why do we want to see it?


If we see what our eyes have been engineered to see and we think it is reality, then is it like the movie, “The Matrix” where we think we are living in reality but we are actually not? If our eyes have holes that our brain fills, do our brains also have holes that our neurons fill in? If we have a blind spot in one of our organs then why would it seem so outrageous that we have some kind of “blind spot” in other organs or maybe even all our organs?


What is reality? Who decides what reality is? If we are all individuals and we have our own perspectives then don’t we all just have our own version of reality? How can someone dictate what reality is or isn’t if they are experiencing their own version of it? Is this website real or is it something our brain imagines is there because we think we see it, but what we are seeing is a screen that tells us we are looking at a website? This topic makes me question everything because it’s a topic of reality. How can I think of reality if I don’t know what reality is? How do we define this term, “reality”? Is it just seven letters that has been programmed into our brains to believe what we are seeing is really what this term means?


I feel as though I am going around in circles and cannot stop questioning what reality is. I want to know what I am seeing is the truth and it is the reality but now I am not sure it is? I seem to look at objects thinking, well if I move my head this way am I seeing everything or am I still seeing some type of a “blindspot”? Do we have “blindspots” everywhere? How do we know? How can we be sure?


On a different side of the same topic, I want to pose another question, How does 3D animation work? We usually see the characters but can see through them, so how do we trick our mind into believing that something is going into the audience if we can somewhat see through the image and know that it is not really there? Is it our eyes that are doing the thinking even though we know it is fake? How do we see and believe that this three dimensional image is really there? If we are looking at the light coming off an object and our brain is analyzing the different types of light coming off different objects to create this image what is 3D and how does it trick our minds?

Darlene Forde's picture

The danger of taking reality too seriously

One of the challenging aspects of this course is that we have to redefine concepts which were previously firmly rooted in our mind. eshuster returns to the question of reality. During the first couple weeks of class we discussed and debated the nature of reality. Some argued for the existence of a "true reality" independent of the observer. Others argued that "reality" is by its very nature subjective. Although we all were all no doubt aware that there are gaps in the information that our minds ability to receive, process, and interpret information from our surroundings, learning about the brain's ability of "making up" or filling in the holes in our vision from our eyes was jarring to many.

I don't see why this should be as disturbing. We know that as human we can only see colors in the range of roughly 400-700nm along the electromagnetic spectrum. Yet I doubt if any of us is concerned that we do not see microwaves, radiowaves, x rays or gamma rays. And if there is a reality these aspects are as much a part of it as are colors.

If we define reality as everything which we can sense (see, hear, feel, touch, etc)—either with our bodies and with the aid of technological equipment—we must recognize the futility of the effort.

Instead of exploring our world and trying gain new understanding, we quibble about whether it is real and whether certain observations are valid.

Quite frankly, I think we need to abandon the concept of reality. Reality itself is a construct which holds us back from understanding out world. Perhaps the gaps in our vision that the mind fills in are the best thing of all and the way these gaps are filled will provide us with an important understanding of who we are as humans.

alexandra mnuskin's picture

patterns, perceptions and the I-function

Like most everyone else in class I was fascinated by the idea of our brain filling in the gaps that the information on the retina cannot supply with something created exclusively by the brain. I’ve read about experiments where people were shown a room and told that it was an office. Afterwards, during a recall session, most of them reported seeing books in it…even though there actually were no books present.  The brain’s ability to create something out of nothing…to process patterns and fill in gaps…this is a truly amazing thing. This phenomenon seems to be completely independent of the I-function. Even when I consciously realize that in a second that dot will disappear and that there ought to be nothing there, a black hole…still I continue to see the paper that doesn’t actually exist. Where then is my I-function? I am not consciously creating that paper…or the extra red dot instead of a yellow one. It follows then that the process is a function of the brain not related in anyway to the I-function. We’ve talked so much about it and now it seems that after all the nervous system really does not have a conductor. It seems that the I-function either has no control over our perception and the various parts of the brain that create the patterns we think we see, or, which is still more disturbing, that it perhaps doesn’t exist at all.   

On another note, it occurred to me that if it’s perfectly normal for the brain to create what it thinks it ought to be seeing then where do we draw the line between sanity and insanity? Why is it normal to see a dot where no dot actually exists and not normal to have hallucinations or visions. Are hallucinations just the products of the brain filling in the gaps? You see an eerie light and you hear an odd noise and your brain leaps to the conclusion that you have witnessed the arrival of an extra terrestrial being.

Cayla McNally's picture

How Did We Get Here?

After reading an article on how Alzheimer’s disease will grow to “epic proportions” as Americans grow older, I have only one real question: why? What has happened over the last century that would cause such an apparently drastic increase in the disease?

As of now, over five million Americans are suffering from the disease, which is a 10 percent increase from five years ago and a 50 percent increase from 1980. It is also affecting more and more people under 65 years of age, and the amount of Alzheimer’s related deaths has risen by a third between 2000 and 2004.

What has changed in the human dynamic over the last fifty years or so that has increased the scope of the disease? This seems to me a very good example of the nature-nurture controversy; has something within us changed, or has the society that we live in affected us so negatively as to make us ill?

lrifkin's picture

"Minority Report"

Over break I had the pleasure of stumbling across a FASCINATING article in March 11th, 2007 issue of The New York Times Magazine. My father had left the magazine, whose cover read “Neurolaw” in bold letters, on the kitchen counter (this article was also referenced by Professor Grobstein in last week's forum). As I looked closer, I was able to see that the entire title read “The Trials of Neurolaw: How Advances in Brain Science Could Transform Our Legal System.” The article was packed with information, and will be the topic of my next web paper.

Although I could write an extensive paper on the article, I will attempt to discuss it in short. The article spoke about the use of neuroscience in the court of law. Due to somewhat new technology, brain scans are now being utilized in criminal trials. Although this is interesting in all cases, it is especially interesting in capital cases, when many philosophical questions arise. Does it matter whether a man killed his wife because mother because he had an abnormal cyst pressing on his arachnoid membrane? Are abnormal brain scans equivalent to acting under duress or suffering from a serious rationality defect in the court of law? Combining these questions with the fact that many scientists are still uncomfortable with how new and untested the brain scan technology is, utilizing it in the court of law is a debated discussion.

Will we force witnesses and suspects to get brain scans? Will jury consultants use brain scans in jury selection? In the future, will we use brain scans to predict actions and crimes?

This article began to scare me as it reminded me of a recent movie called Minority Report. The films tagline was “What would you do if you were accused of a murder, you had not committed…yet?” and followed the adventure of a detective who was accused of thinking about committing a crime he was not planning on committing. Science, similarly to everything else in life, cannot be perfect 100% of time. However, I was comforted to know that a coalition of social scientists, psychologists, lawyers, and biologists have all joined forces to fight for the ethical use of brain scans.

Again, I apologize for the brevity of this post. My webpaper promises to go into more detail.

x's picture

Reading Brains

I don't know whether to say the possibility of Minority Report becoming reality is awesome or horrifying. I am intrigued by the idea that a brain scan can predict or somehow illuminate what people are thinking. I thought those technologies could only be used to detect tumors or other kinds of physical, medical properties in the brain. Can they now detect emotional ones too? Can these machines translate certain actions of the brain into a language that we can interpret to better understand people's actions?

This is intriguing (or dangerous, depending on who you ask) on so many levels. Will people with certain kinds of mental disorders soon be able to go in to a doctor and be told exactly what they're feeling based on reactions in their brains? Will people be able to validate certain parts of their identity construed as choice (sexuality, for example) based on certain reactions in the brain?

The mixing of science and law is also fascinating. I want to read your web paper :)

csandrinic's picture

vwl nfrnc?

Have any of you ever been asked this question:

Wht mks t s tht y cn stll rd ths sntnc vn thgh thr r n vwls n t? 

I, for one, had always read things like this and thought about how silly they were (and promptly deleted them). However, it was in Thursday’s class that I actually realized how incredibly smart this is and what it implies about the dynamics of our vision. Essentially, what you do is remove all of the vowels from a sentence or a paragraph. The amazing thing is that you are still perfectly capable of understanding what you have read despite the fact that you are only reading a bunch of consonants. The sentence above (in case you didn’t get it) is ‘what makes it so that you can read this sentence even though there are no vowels in it?’ This is a very good question, and I feel as though Thursday’s discussion allowed me to better comprehend this phenomenon.  

 By looking at the nature of the retina and the difference between the image on the retina and the image in our head, we were able to infer that our brain fills in what it believes there should be. In the same way, therefore, that the brain fills in the holes (from where there are no photoreceptors in the retina) in the picture in your head, can your brain fill in the ‘holes’ left by the vowels in words? What we can take from this example is that words are not read letter by letter; rather we recognize words as wholes, and the absence of vowels does not reduce the understanding of our text. Another interesting question that this brings up is what role the I-function plays in reading. It would seem that by automatically filling in vowels when you are reading a sentence like the one above, you are essentially interpreting things which have nothing to do with the information that is coming from your eye. In the same way that unbeknownst to you, your brain is adding visual images that are absent on the retina, is there a part of your brain or nervous system which is creating the experience of reading whole words even though that experience is non-existent?

Aditya's picture

Mysteries of the Brain

The brain works in mysterious ways, everyone knows this, but there are two specific things about vision I have learned this week that have lead me to question the implications of the mysteries of the brain: 1) The retina is organized backwards with the photon receptors being one of the last layers that photons of light penetrate. 2) The location where the optic nerve connects to the retina, no light receptors exist, and there is a blind spot in the world we perceive that our brain fills in, independent of influence from our “I” function.


Getting to the retina is organized backwards. Nobody knows for certain why the retina is organized this way. Wouldn’t we want these photon particles of light to first hit photon receptors? But then from other things taught to us, it seems like the brain is evolutionary organized in the most parsimonious, and logical ways. For instance, we learned about how action potentials are the sole currency for transforming information of all types throughout the nervous system. Evidence of this nature illuminates the simplistic methods the brain utilizes in order to carry out complex function. This gives me the confidence to think, because we do not understand why the retina is organized backwards, it is likely due to a limit of our methods of research and understanding. I think the retina is organized backwards for logical reasons that we are not yet capable of understanding because I feel like everything in the brain was thoughtfully and purposely arranged. But I also understand I could be wrong. We could still be evolving. Maybe a million years from now, the photon receptors will be the first layer in the retina.


Learning about how the brain fills in the blind spots of where we lack photon receptors, independent of our “I” function, this to me, is another piece of supporting evidence of the other part of our nervous system independent of our “I” function that is also in control. We touched on this part of our nervous system like when we talked about how we know how far away things are from us without thinking about it. But I think it is amazing yet scary how much control this part of the nervous system has. To fill in blind spots, is essentially altering reality. What we are perceiving is a rendition of what the brain is allowing us to see. Would we rather want to see blind spots so we are aware of the true limitations of our body? Echoing what other people have said, how far does the control of this part of the nervous system extend? On the other hand, I don’t think it is too dangerous that it is only filling in a small spot with matched patterns of the surroundings. It is not really altering our reality but allowing us to have a unified sense of picture. Is this really a bad thing? After all our eyes are constantly moving, so what is in the blind spot at one point, is not in the next instance? Are we really not perceiving all of reality? That the brain fills in these spots, is this a good thing or a bad thing? I think for the most part good, Id rather have a unified picture without holes in it.

eden's picture

Why evolution is dumb as rocks


I wanted to comment on your musings about the organization of the retina. In your post you said:


In response I'd like to mention something else:

The larygeal nerve is a branch of a cranial nerve and gives control to the voice box. In mammals the nerve starts in the brain (of course), loops down and around a ligament of the lungs, and then finally makes its way back up to the larynx where it serves its purpose. Frankly, this arrangement is stupid. In giraffes it means that the nerve has to be about 20 feet long as opposed to about 1 foot. So why is the nerve arranged like this? Well, I'll tell you. Mammals evolved from fish-like ancestors that are morphologically very similar to modern-day fish. In a fish, the position of the shoulder girdle makes the pathway for this nerve a straight line from the brain to the larynx, and it happens to pass behind a ligament of the swim bladder on the way. As our fishy ancestors evolved into terrestrial beings with lungs instead of swim bladders they developed neck regions and this nerve was still wrapped behind that stupid ligament, simply because when the first fish evolved it made no difference at all that the nerve went behind as opposed to in front of the ligament so the fact that it went behind was completely random. However, it just isn't possible to disconnect the nerve and reconnect it in front of the ligament, so it just had to get longer and longer to compensate. Pretty dumb, huh?

I guess what I'm trying to point out is that evolution is completely undirected. It isn't about "what works BEST" its really just about "what works," or even, "whatever happened to come first that kinda worked." I'll be honest that I sincerely doubt that the problem here is that we don't know enough about the eye to understand why it is organized this way, and also, most likely the layers won't ever switch positions, simply because as far as evolution is concerned the current organization is "good enough" so there isn't really a selective pressure that would make any random mutation that might happen to occur (which, by the way is highly unlikely because it would be an extremely complex process to switch the positions of the two layers and the likelihood that a mutation like this would somehow happen, or that any intermediates would be favorable in some way that would even allow the process to continue is virtually zero.) be favorable. Evolution has no purpose, and our brains can’t direct it at will. It has no goal. There is no presentiment on the part of evolution. It is essentially random except in the sense that if a mutation that randomly occurs is favorable, that individual might stand a better chance of surviving and reproducing. Or it might get eaten the day after it's born. That’s why this stuff takes millions of years and you still get bats with solid bones instead of hollow ones like birds. Its just plain random.


RachelBrady's picture

Depth Perception

            In class we learned that the image produced by the absorption of light on the retina is not the same picture we ‘see’. That image is modified in the brain through the process of imaging and is the result of photoreceptors as well as other inputs and expectations in the nervous system. One difference between these two pictures is the dimensions; the image on that appears on the retina is two dimensional, but we experience a three dimensional world.

            I did some searching to account for this difference and found that Stereopsis is an important cue to depth perception in. Stereopsis refers to the ability to distinguish the relative distance of objects with a physical displacement between the objects. The lateral displacement of the eyes provides two slightly different views of the same object. Because each eye views the visual world from slightly different positions, each eye's image differs from the other. Objects at different distances from the eyes project images in the two eyes that differ in their positions. This is retinal disparity and is important in the perception of depth by stereopsis. Retinal disparity within the zone of focus in each eye can be fused resulting in the convergence of the optic axes of the two eyes. Due to the lateral displacement of our eyes, slightly dissimilar retinal images result from the different perception of the same object from each eye.  Stereoscopic depth perception results from fusion of the images in each of the eyes.

            One draw back to this process is that when the two images don’t match up (that is there is an object in one and not the other) suppression, superimposition or binocular rivalry may occurs. Suppression occurs to eliminate one image in order to prevent confusion. Superimposition results in one image presented on top of the other image. Binocular rivalry describes alternating suppression of the two eyes resulting in alternating perception of the two images. This usually occurs when lines are presented to the two eyes differ in orientation, length or thickness. These modifications in the fusion process account for some of the optical illusions we experienced in class.

francescamarangell's picture

Thinking about Pain

In class we learned that pain is not a sensory modality and yet I feel as if I am able to sense pain. If I scratch my arm, I feel the pressure of my finger, but also a sense of pain. Oftentimes if a person gets a cut, he doesn’t realize that it hurts until he sees the cut. The pain appears to be initiated by his visual confirmation. However, if I scratch my arm while closing my eyes, I still feel both pressure and pain. There is more to it then the visual reafferent loop. If pain is merely a device of the nervous system, then is it a learned device or do we innately possess the ability to feel pain?


What exactly is pain? Biologically the pain we experience is separate from nociception, which is the measurable and physiological component to events that usually involve pain. However, pain can occur without nociception and visa versa. Nociception involves the transferring of information, such as inflammation or damage, to the brain and spinal chord. (wikipedia: pain and nociception) Pain doesn’t seem to hold any physiological component. Does this mean it is purely psychological?


A.Kyan's picture

response to thinking about pain

I have a few questions of my own regarding pain.  I mentioned before that I had a revelation during a meditation retreat when I was finally able to surpass (relatively) painful sensations.  It was very liberating.  I was already four weeks into the retreat, and my inflexible hips made it so difficult to comfortably sit in a lotus position for long periods.  First, my legs would fall asleep, then sharp stabs would escalate throughout my right knee.  My goal at that time was to sit as long as possible without moving.  That means, not scratching any itches, not adjusting my legs, and not peeking to see how much time was left (we were expected to sit for a minimum of 1 hour per sitting). 

When I was able to fully concentrate on the sharp pains in my knee and hip, I noticed the pain was a series of different sensations.  It first began as intense heat, then a series of sharp pricks, to throbs that resonated, etc.  There were other sensations mixed in, and the feelings were always, rapidly changing.  When I was able to sustain that focus without a stray thought or wandering of the mind, the mind or should I call it my I-function became disassociated from the pain.  The mind became this outsider to what was happening in my leg and was able to witness the pain as if it were happening in someone else.  (Does this sound crazy?!)  I could identify the sensations as they were, and that prevented my mind from identifying those feelings as discomfort or pain.  Sharp pricks and heat suddenly were neutral to my mind.  It did not felt good or bad- it was just what it was. 

Similar to how the anatomy of the eye tricks the brain into seeing or not seeing actual images, I wonder how one can biologically explain how the mind clouds the nervous system and brain’s signals, and what did my brain activity look like during that meditation session when I sustained concentration long enough to not feel any pain or discomfort? 

Molly Tamulevich's picture

Pain and the eye

I was wondering a lot about generalized pain after we learned about the eye.If nausea is the brain's response to a nonlocalized interruption of patterns, why am I not dizzy and nauseous whenever I don't wear my glasses? Would someone whose vision suddenly changed feel pain due to the new patterns of light being picked up by the eye, or does this have nothing to do with pain? Maybe I am accustomed to the changes in focus from my natural-horrible-eyesight to my glasses to my contacts, but does this change have the potential to cause the generalized interruptions that lead to pain? If people born without limbs can still experience phantom limb symptoms, could people who have severely damaged eyes or who were born blind experience pain becasue of expected pathways that are never completed? Or, if someone was born blind and missing a limb, would they experience phantom limb pain? They could not see the missing limb, but they could still feel its absence when compared to the other limb. What exactly constitutes "experiencing" these pathways in a way that their interruption causes pain?

Stacy Blecher's picture

How Smart is the Brain?

A lot of people were very upset by the prospect that our visual system does not provide us with an image of what is actually being viewed.  That is, when there is a lone yellow dot amongst a bunch of red dots it appears to be red unless it is the focus of attention.  This specific example of the brain producing an image that is not true to “reality” does not particularly disturb me, but it does make me wonder how “smart” the brain actually is.  I think that the brain is probably really good at detecting patterns, but perhaps relies on this ability a little too much.  Then again, it’s only one measly dot on a piece of paper.  Finding out that the dot is actually yellow as opposed to red does not exactly cause my world to come tumbling down.  There are definitely some perks to the eyes and brain being able to work so well together to detect patterns.  We are able to make out what objects are even if they are not illuminated or if there is a strange shadow cast on them.  Also, we are really good at identifying shapes even if they are distorted when they reach our eyes.  That is, if we are looking at a window from a side angle, the corners of the window as we see it do not form 90 degree angles.  The image that is produced on the back of the eye is probably something that has characteristics more similar to a trapezoid, yet we perceive the windows to be rectangular without even thinking about it.  So it seems that there must be more to seeing than just photoreceptors reporting to the brain.  There are basically four things that seeing tell us:  the shape, the position in relation to other things, the color, and the motion or change in orientation of the object over time.  I wonder if each of these characteristics is determined in different areas of the brain.  If one of these areas of the brain were damaged, could the others possibly make up for it or “fill in the blanks” the way the brain does in the dot demonstration?   

Jessica Wurtz's picture

What We See...

I read Stacy's post on how one might find it disturbing that what we see is not necessarily what is actually there, and I had a somewhat different take on this concept. I feel that the fact that the brain fills in a red dot for a yellow dot or whatever, is not a problem because that isn't what is actually there, but rather an amazing ability of the brain to make up for a small flaw in the visual system. There's no way to get around the fact that the optic nerve has to get to the retina and then to the brain somehow, and as a result, there is a sopt with no photoreceptors. I am so grateful to my brain for filling in a red dot where there is actually a yellow dot because if it did not have this capability, how annoying would it be to have a blank spot in your line of sight?  I am much less disturbed by this so-called false reality the brain creates than I think I would be if I had a black hole in the middle of everthing I looked at with one eye closed.

kgins's picture

mind wandering/reality

I was thinking about reality... about our concept of it, about just how much we can know at one given time.  I went from idea to idea, in much the same way that I started off with one topic for a web paper, and, after researching, ended up with a completely different topic. But, with this mind wandering, I got to a certain point before I made relative peace with the topic.. before I logically thought out as much as I could for the moment. A little while later, while I was walking somewhere, a new idea came into my head.. a new way of looking at the world, or at reality, that made me think. I asked my sister, who's 10 years olderr than me, about these revelations- or whatever they're called, and she told me that she used to have them a lot, but now, not as much. I wondered if age, or current situation, or experience, has an effect on these mind wanderings.. if we can have more random thoughts/revelations if our minds are clearer.. or maybe if they're in use, constantly working, finding holes to fill with these random thoughts? Maybe it's just sometimes some of our minds are looking to make life and the world, the observations concerning both, make more sense, be more logical, in a way. Maybe we all have these thoughts about different things, and maybe these different revelations we each have play a large role in making our worlds so different. It concerned me that my sister said she used to have these thoughts often, but over time, they lessoned.. maybe that specific part of the brain concerned with these thoughts had another, seemingly more important job, that took over the role? Maybe it's just where you are, that either encourages or discourages thinking about reality.. maybe, once you're out of the academic setting, and the "real world" is more real than ever, the brain finds mind wandering more confusing and detrimental.. but, for some people, maybe this uncertainty is what thrills them about life- about not being able to make sense of it- about being able to have these interesting new thoughts about interactions and the world around them... so finally, at the base of it all.. what is it that makes us interpret the world so differently- that makes some people more interested in attempting to understand reality, and observations, while some people don't have these random thoughts about the world around them? Maybe there's no correlation between the two..maybe some people interested in these thoughts just don't have them, and vice-versa.. 

Stacy Blecher's picture

Fat Bastard said it all...

In the movie Austin Powers, there is a touching scene in which the character Fat Bastard proclaims, “I eat because I’m unhappy, and I’m unhappy because I eat. It’s a viscous cycle.”

I realize this is a silly example, but it does address the issues of control, purpose and obesity. Does Fat Bastard have control over when he feels hungry? Hunger is a very tricky thing to judge because we almost bred to “eat our emotions.” Since babies can’t tell their parents when they are beginning to feel hungry, they essentially wait until their blood sugar drops to a level so low that it triggers an emotional change. The change is generally from a fairly stable state to a nearly hysterically stressed and unhappy state. Crying and screaming alerts parents that their baby needs to be fed ( or that their diaper needs to be changed ), they feed the baby, the baby’s blood sugar goes up, stress is alleviated and crying ceases. So, we learn to associate food with stress reduction in infancy!

As babies, this system was very effective. It worked because there was practically nothing else in our lives causing us to get stressed. Blood sugar drops due to hunger, baby gets cranky, cries, eats, blood sugar goes back up (along with an increase in serotonin, dopamine and serotonin that are found in foods), baby feels happy again.

As adults, there are a myriad of issues that could cause stress and in effect a change of chemical levels in the brain. It makes sense that we reach for a tub of Ben and Jerry’s when we have three papers to write in one night because when we were babies food made it all better, so we assume it will do the trick now, too. But what happens instead, is what fat bastard describes –a viscous cycle. We are unhappy about something and instinct tells us that in the past eating has alleviated this discomfort. But now, while eating might momentarily boost serotonin levels and put us in a good mood, we soon realize what we have done and become unhappy again.

There are a few possible explanations as to why people lapse back into their unhappy state. I think that one of the primary reasons is that people realize that they are not in control. If they were in control then they would be able to resist eating the Ben and Jerry’s because they would recognize that the feeling they are experiencing is not “real hunger” but simply stress. It is upsetting to have this experience time and time again yet never learn that you are being “tricked” into eating. It is also the case that people are attempting to use food for more than it’s intended purpose. The purpose of the behavior eating is to satiate hunger, NOT calm a stressed out college student. We try to take control and make this behavior serve another purpose but it simply does not work. Another people try to gain control is by not eating at all, a condition known as anorexia.

But while anorexics might feel like they are in control, they are ironically being held hostage by their passionate desire to control….if that makes any sense. It seems that even people who have amazing will power when it comes to food –people who maintain a healthy balanced diet etc – are not completely in control of their weight. According to an article on women’s health, metabolic “set points’ are established in the womb before we are even born. The set points are determined by ( among other things ) the mother’s nutrient consumption and the blood sugar levels that she passes on to her baby. So I guess in that sense we really do not have any control. Yet, I’m still a firm believer that with the right diet and exercise most anyone can lower their weight and fight obesity.