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Week 9 - Neurobiology and Behavior

Paul Grobstein's picture

So, if the brain isn't organized to give on a picture of "reality", what is it doing?  And how does it do it?  Or, of course, any other thoughts that you've had/want to share this week.


Caroline Wright's picture

Repressed Memories

I've been reading about emotion, especially fear, and how it affects memory. There are two types of memory: explicit, which deals with conscious thought, and implicit, which deals with subconscious thought. You brain creates implicit memories of details in an experience that you don't consciously observe, or things like feelings, scents, or even sounds that occur during an event. When your body is undergoing any type of "flight or fight" response, levels of certain hormones or proteins in crease in your body that encourage consolidation of these fear memories. Where it gets interesting is when this idea is applied to people who have, for example, suffered some type of abuse at a young age. Obviously there is a high amount of emotion and fear that is going on during these events, but the strange part is that sometimes the response is SO strong that the memory is actually repressed. Often these people don't remember the event occurring at all until a later point in their life when they heard a certain sound or smell a certain smell or feel a certain feeling that was stored during the time of the incident and causes the memories to come flooding back to them. It is said that perhaps during these types of events, especially if they were repeated, one's brain can shut down in a sort of self-preservation response which might account for the lack of explicit memory in these cases. The whole idea of these repressed memories is very controversial and it is hard to discern who is really experiencing them and who is not. However, the idea remains that when this happens, a person's brain is changing their reality. If they had never experienced that "trigger" that caused them to rush back to the moment in the past, they would never have known about it, perhaps never have known why they have always been depressed or had some sort of relationship issue. The brain makes choices about what it wants to remember and what it doesn't all on its own, with out the conscious control of the person themselves. It's almost as if our reality of a situation is in a locked box inside the brain itself.

Stacy Blecher's picture

Is my red the same as your red?



            What if when I was young someone showed me something that reflected light at a wavelength of 700 nanometers and said, “Stacy, this is blue.”  Similarly, they showed me something that reflected light at a wavelength of about 450 and said, “Stacy, the is red.”  In this case, my idea of red and your idea of red would be quite different.  Color identification is a learned skill, not something inherent and also not something necessarily exclusive to humans.  You can train animals to recognize certain colors and what events, emotions or experiences are associated with them.  Calmness or a soothing feeling has been said to be brought about in humans by the color green.  Studies have shown that the presence of the color red can stimulate people to make quick decisions, which is why a lot of the buttons on the internet that say “Click Here!” or “Buy Now!” are red.  Would I be affected by this marketing ploy?  Is it the specific wavelength (or relative amount of activity in two receptors) that triggers these emotions or does it have more to do with our socialization?  I suppose if the emotions are the product of some specific interaction between specified wavelength and an emotion transmitter, then I would experience “red emotions” such as impulsiveness, sexuality and revenge every time that I saw a something that was blue to me.  On the other hand, if these responses to color are socially generated, that is, if we are socialized to evoke specific emotions in response to certain colors, then it is possible that when I see a “Buy Now!” button that reflects light at 700 nanometers I become calm, patient and tranquil because, to me, that wavelength represents the color blue and the preceding feelings are considered to be “blue emotions.” 

            I wonder if these emotional responses are an evolutionary response to our environment.  Water (such as oceans, lakes, rivers etc) makes up approximately 70% of the Earth and reflects around 450 nanometers, or the color blue.  Perhaps if the oceans were red we would become calm at the sight of 700 nanometer wavelength.   

Stacy Blecher's picture

In class today, someone

In class today, someone questioned whether all organisms are conscious.  We tend to assume that Homo sapiens are far superior to all other animals and living organisms.  However, the article in New York Times Science Times about time in the animal mind eliminates some of the distance we try to place between ourselves and animals.  The article discusses experiments carried out on birds and monkeys in which it was discovered that these animals seem to be capable of remembering the past and also predicting and planning for the future.  Knowing that animals are able to remember, predict and perform various other tasks formerly thought to be exclusive to humans, makes me wonder if animals interpret visual cues in a similar fashion as humans.  Aside from the fact that many animals have a different proportion of cones to rods in their eyes, it is possible that, like humans, visual stimuli are experienced by the eye and subsequently trigger brain activity that ultimately results in the image that is seen.  If this is true, then (figuratively speaking) if a tree falls in the woods and a bird is there to witness it, yes, it makes a sound.

Also, if animals process information in their brains similarly to humans, then they should be equally susceptible to such things as optical illusions.  Even animals that lack cones or have very poor vision should perceive optical illusions because the picture is pieces are put together and processed in the brain, not the eyes.

michelle's picture

You See what I See?

I can’t help but check my thoughts and question my perceptions of the world every time I leave class. Leaving class today I began appreciate the scenery of Bryn Mawr just a little bit more than usual. I felt like I was actively embellishing what was already there. I (my brain) decide what the different wavelengths of light should look like. It is crazy to think that our brains could have perceived these different wavelengths of light in any way, but they choose to interpret them as something visually aesthetic. The world is so beautiful because we make it that way by adding color to it.

Other things I began to notice is that a majority of the things in nature are green, blue, and reddish (brown), which may explain why our cones have only the ability to detect green, blue and red. The sky and ocean are blue, plants are green and the soil is somewhat red.

Although there is an obvious evolutionary advantage to being able to detect colors, there seems to be a more aesthetic appeal to it. This idea got me to question the usefulness of all the senses because we seem to take advantage of their pleasurable qualities more so than their practicality. For example, we as humans listen to pleasing music and sounds, we like to smell flowers, perfume and things baking in the over, we like to admire beautiful artwork, we like sweet and salty foods, and we like to feel soft, smooth things. I could understand how the pleasurable responses to some senses are evolutionarily advantageous, like being attracted to sweets and salty foods because carbohydrates give the body energy and salt helps regulate membrane potentials. However, why do we find pleasure in some of the other senses? Is it something we as humans have learned to do over time i.e. make the best of what we were given, or is it important to succumb to these pleasurable urges in order to satisfy our biological needs?

I also began to wonder why then does the world cater to our “false” perception of the world if our idea of color is something that is made up by the brain. For example, a lot of different animals have the ability to camouflage them. If animals can’t perceive colors quite the same as we can, why do they disguise themselves but changing their colors to match their surroundings if only we can sense the colors of the animals and their surroundings. I looked into what animals can actually see and found this response online from Dr. Ziesmann:

Many animals have the ability to see colors. This ability is based on the types of visual pigments in a cell. There are animals known with 2, 3, or 4 different pigments or visual cell types. Humans have 3 different pigments and can differentiate about 200 colors. Most of this analysis is done by the brain, not the eye. Therefore, it is difficult to tell how many colors an animal can differentiate based on the number of their eye pigments alone.

Many fish can see colors (e.g. Phoxinus, Crenilabrus). Some amphibians can see colors (frog: Rana temporaria, toads: Bufo bufo, some salamanders) and they usually have two pigments. Most reptiles can see colors (snakes, turtles). Birds: general rule: birds that are active during the day can see colors, but birds that are acitve during the night cannot. Mammals are generally bad in color vision. Examples of color-blind mammals are rats, hamsters, rabbits, and dogs. Cats are weak, but can see some colors. Mammals that are quite good are guinea pigs, sheep, zebra, horses.

Also some invertebrates are able to see colors. Some Cephalopods (e.g. sepia, but not octopus). Crabs are generally good in color vision. Many insects (all beetles, hymenopterans (bees, wasps, ants), homopterans (ture bugs), and all flies. All insects are unable to see red light (only known exception are ants), but some are able to see UV (ultraviolet) instead. The color vision was determined by training an animal to respond to a color or by measuring the electrical response of single visual cells or the whole eye.

The majority of animals that have the ability to camouflage themselves are usually fish and amphibians, which now makes sense because they can see colors as well. Therefore humans aren’t the only organisms that “make up” things in their brains. This new information furthers my belief in the existence of a reality that is the average of what we, organisms of the world, perceive.

lrifkin's picture

Memory and Vision

After reflecting upon our discussions from class, I read an interesting article on titled “How The Brain Turns Reality Into Dreams.” The article was written by Kathleen Wren and discussed how memory affects our “vision” when our eyes are closed. Ms. Wren wrote about dreams, and about what people see in them. Often, she explains, individuals wonder where their dreams have come from. However, there is a logical explanation for what we see when our eyes are shut. She explains that much of what we dream has been traditionally thought to come from recent experiences or newly learned information. This type of input is known as declarative memory.

Ms. Wren then cited a study out to prove that dreams come from implicit memories, or memories that we do not know we have. In this study participants played the game “Tetris” as day. At the end of the day, some participants remembered playing and some did not (not all individuals involved in the study had “normal” memory). However, when the participants went to sleep, a majority of them described “seeing” falling blocks. All participants, regardless of their memory impairments, spoke of this phenomenon.

Thus, Ms. Wren’s article has caused me to question “seeing” with our eyes closed. Although I do not doubt our ability to see light with our eyelids shut, I do wonder how much of what we see is based on memory, versus actual vision. Could it be the case that when we close our eyes and “see,” we are actually composing a picture of images from the past?

Darlene Forde's picture

And the Brain turns Dreams into reality?

I have always been fascinated by the mind-body connection. More specifically, I have been intrigued by attempts to use dreams to structure a new reality. My personal library reflects this preoccupation with books that would be classified as"motivational". Including such motivational classics as Napoleon Hill's Think and Grow Rich, David Schwartz's The Magic of Thinking Big or Dwayne Dyer's The Power of Intention. One common thread in these books is that if you concentrate on something and focus your energy on it is more likely to happen.

For example in Write It Down, Make It Happen, author Henriette Anne Klauser offers a technique which may be useful in "teaching" our nervous system new pathways. On a superficial level we may understand this as a mere visualization technique. According to Klauser, the process of writing down our goals and aspirations activates our reticular activating system (RAS)—"believed to be the center of arousal and motivation in animals (including humans)", "crucial for maintaining the state of consciousness". (Wikipedia). RAS sends helps the brain to distinguish between what is important and what is unimportant. She describes RAS as awakening the brain to consciousness as it filters input and data from our inputs.

If we extrapolate from this, we may imagine that repeatedly writing down our goals and aspirations would activate our brain on a number of levels. When we write we create a picture in our head that is visual, varied receptors (i.e. our mechanoreceptors, chemoreceptors, proprioceptors, etc) are at work during this process. They will create or reinforce certain synaptic pathways in our brain. We are in effect teaching our brains new patterns of synaptic firing which it can recognize. This leads to creative thinking as our brains "learn" to interpret new information in terms of this pathway.

For example, if you wanted to buy a home in the ideal neighborhood at just the right price, the process of writing down your goals everyday would develop a neuronal pathway pattern of house buying. Later that day when you see a newspaper, your brain might trigger your this pathway and "inspire" you to examine the real estate section of the paper or remember that you know a friend of a friend in real estate.

The long and short is that there are different ways of creating and establishing neuronal patterns. We should think of ways that we can strengthen and develop these systems to create patterns and establish behavior in the ways we want.

csandrinic's picture

Was blind but now, I see

I was really interested by the lateral inhibition network that we talked about in class last Tuesday. If I understand correctly, the lateral inhibition network essentially creates the concept of an object; it creates the feeling of constancy despite variations in light conditions. Obviously the wavelength composition of the light that is being reflected from an object is constantly changing depending on the time of day. The thing that was most interesting to me is that there did not seem to be any use of the I-function in creating this constancy. However, I believe that in many ways experience plays a large role in our interpretation of color and objects.

Numerous clinical and physiological studies have shown that people who are born blind and to whom vision is later restored find it very difficult, if not impossible, to learn to see even a few forms. In 1910, two surgeons operated on an eight year old boy and removed the cataracts that had made him blind. They thought that they would miraculously make him see; but when they moved their hands in front of his face and asked what he saw, the boy answered ‘I don’t know’. He could only see vague changes in light, not a moving hand. What can be taken from this example is that without visual input from early developmental stages, it is difficult to develop another essential stage of visual processing. It seems that there is also a physiological aspect of vision. The message that the eyes and the retinas send is pure information. We require another stage in order to interpret and determine what we see.

What I can discern from this, therefore, is that vision is much more of an active process than just light reflecting onto the retina. There is also an external and physical element which has to do with one’s exterior environment; in order to properly recognize an object as such, does the selected visual information have to be compared to our previous knowledge? Then all of the properties that we attach to objects are in fact interpretations that our minds create, rather than actual ‘reality’, and this ‘reality’ relies primarily on our previous experience. Does the I-function therefore play a role in our visual process?

Shayna or Sheness Israel's picture

The Matrix: Digital Reality: Further from Reality than You Think

This past weekend, I watched the Matrix. For all sorts of reasons, many things in it are directly applicable to things we have learned in class thus far. The one that interested me was the idea of not really seeing reality.

In the Matrix, Neo evolved in his consciousness when he saw that the world he believed was "real" was just a program that he did not learn to hack yet. Once he opened his mind, he saw the world as a number series, something like a digital number series. When he saw this code, he realized that he could manipulate its once seemingly insurmountable configuration for his benefit: he was stopping bullets, moving at ridiculous speeds, and whatnot.

It made me wonder, are we even further from seeing reality than we thought? What does it mean for people who always defy or bend rules? Are they more equipped to see reality or at least know the ways to manipulate it? What about people who break clay blocks with their head without harming themselves? Have they learned to hack the code?

Another thing that was intriguing in the Matrix was the fact that people were actually grown and were plugged into the Matrix. While plugged in, their lives were encoded in this film that they were unaware of. Would I want to know a reality where I found out that I was plugged into some Matrix and all I knew to be “real” was programmed? Hell yeah; however, I would not want to be the only one “freed.”


alexa09's picture

a perfect apple through imperfect eyes


When I drew a picture of an apple, my art teacher told me it was wrong. I thought, how can a drawing of an apple be incorrect? It has a sphere-like shape with indents on the top and bottom, a stem, and a leaf. My teacher said that my drawing was of a very pretty apple, but incorrect none the less. I had drawn an apple that did not exist; an idealized apple, without the imperfections in texture and shape like the apple in front of me.

It’s interesting to find that we do indeed have ideal images and thoughts of how things should be. However it is hard to realize that we do idealize everything we see. Our eyes see one thing and our brains seem to tell us another. Everyone has different ways of seeing things although the same “equipment” is being used (eyes, neurons, brain). Perhaps the brain is behind the different interpretations of what everyone sees. “Beauty is in the eye of the beholder;” this is a very true statement if everyone’s brain is interpreting things differently. There is also the level of detail that a person’s brain catches. When flipping through the pages of I Spy some people can spot the items much quicker than others. Assuming that everyone has perfect vision, naturally or by other means, everyone has the ability to see the hidden items. It is the brain that deciphers these images to actually see realistically what is on the page.

Ian Morton's picture

An article from Nature on vision, executive function...

I just wanted to briefly introduce an interesting article from the May 2001 issue of Nature titled Decisions, decisions.  This article discusses a possible locus of brain decision – a master box for the ultimate convergence of sensible input into motor output.  William Newsome working with Michael Shadlenn and colleagues have located what they believe to be “decision neurons,” first located in a brain region linking visual processing and eye movement, the LIP, and later in the prefrontal cortex.  Discovered in monkeys while monitoring the activation of specific neurons in response to left/right movements of dots, Newsome and Shadlenn believe that decision neurons monitor the activity of cells that respond to left or right movements (through corollary discharge?) and then send signals to the superior colliculus, which controls movements.  Eventually, these men were able to predict the direction of a monkey’s eye movement based on the firing of a single neuron. 

Ranulfo Romo of the University of Mexico has continued studies on these neurons and proposes that there are decision neurons within the prefrontal cortex that act independent of sensory input.  While highly speculative, this would be the central locus of decision making.  Decision neurons could also be involved with deciding what simplifications to make during visual processing from visual input to form the image in our brain.  I recommend that you read this article for much more detailed information.

Meera Seth's picture

"What's So Funny? Well, Maybe Nothing"

In a recent New York Times article (3/13) entitled "What's So Funny? Well, Maybe Nothing", John Tierney explores the significance behind seemingly casual laughter and the evolution of this (re)action of laughter in human behavior.

Neuroscience researcher Robert R. Provine studied laughter in the context of watching stand-up comedy on tape opposed to laughter in the context of casual conversation and social interaction. Provine found that while few participants laughed at the prerecorded stand-up routine, the individuals (especially women) engaged in casual conversation with friends or acquaintances laughed much more. According to Provine's study of thousands of first-hand interactions, 80 to 90 percent of laughter followed such non-humerous lines as "I know" or "I'll see you guys later."

Laughter is an honest social signal because it's hard to fake," Provine claims. "We're dealing with something powerful, ancient, and crude. It's a kind of behavioral fossil showing the roots that all human beings, maybe mammals, have in common."

It seems that laughter is much more than a mere human reaction to humor. Rather, in many circumstances, it could be labeled an evolutionary trait in all of us. We are not at all conscious of our laughter. According to Provine's discoveries and similar recent research, such an outward behavior is, more or less, automatically manifested. Having said this, can we control this kind of behavior, supposedly hardwired and imprinted within us from birth? If not, is each individual a helpless victim of her genetic code?

Alex Hansen's picture

Concussion and light?

Earlier today I was having a discussion with someone about concussions and how we are affected by them.  A concussion, also known as a mild traumatic brain injury occurs as a result of physical trama that alters neuronal metabolism and excitability causing the brain to enter into a state of "hypermetabolism."  A concussion is usually marked by unconsciousness, confusion, vomiting and visual disturbances.  Other qualities include anmesia, headaches, drowsiness, ringing sensations in the ear, unbalanced pupil size, and disorientation.  The damage that occurs leading to these symptoms and qualities of a concussion most often is located in specific areas of the brain.  These areas include the cerebral cortex, or the reticular formation of the brain, and the cranial nerves.  However, there do exist arguments that state that the damage occurs to all consisting parts of the brain.

First off, the fact that when a concussion occurs, the idea of reality is altered, is a very interesting phenomena, especially in regards to our study of the brain and the behavior associated with the brain.  This mild traumatic brain injury leads to further questioning of what exactly is reality?  Is it a construction?  To the patient, the world that he or she is living in seems perfectly normal and most often they feel fine, while those around them do not agree as they experience the patient's inability to recall basic information and perform basic calculation or answer basic questions.  How is it that the brain can all of a sudden lose this information that a five year old would be able to know.  How is it that we appear normal to ourselves after experiencing this trama, but damage has occured to our brains?  Yes, you can become light headed, vomit, and experience wierd sensations, but still we often deny that we have lost brain power unless we are asked a question and acknowledge that we have trouble solving the simpliest of problems.  Does society play any role in this situation, for basically, we are admitting stupidity if we admit we are unable to answer the question, and at least in my opinion, no one wants to feel that they are stupid and cannot answer a simple question such as two plus two.  However, it is very interesting to interpret all of this and the ability to lose this information so rapidly.  If the brain can almost enter two different worlds in a sense, what else is it capable of?  What truly is reality?  What is the brain's true capacity?

Moreover, I began thinking about this all for I began to relate concussions to our discussion of light.  We discussed how perception can be different for different people, and thus, which is correct.  Well who is to say then what occurs when experiencing a concussion is not correct, and the images are not real.  The brain is known to float within the skull which is surrounded by cerebrospinal fluid which protects the brain from normal light trauma.  Thus, when the brain trauma occurs, how exactly is the brain affected by light in the aftermath?  Does color mixing occur in the same manner?  Are there any changes in absorbances and observed colors as color is a function of the brain.  How exactly is depth perception altered?  Monitering the brain of a patient experiencing this mild traumatic brain injury would provide interesting information in exploration of these questions of the brain and its varying functions. 

Claire Ceriani's picture

Whatever the brain is doing,

Whatever the brain is doing, we seem to get along just fine.  By the laws of natural selection, our brains have evolved and adapted to fit our environment and meet our needs.  Seeing true reality apparently isn’t necessary to make it to the top of the food chain.  We’ve organized our lives and perspectives around the reality our brains construct for us.  We wouldn’t know how to get by in true reality, because our brains wouldn’t know how to interpret it, unless they’d evolved to incorporate all of that information.  Other animals have adapted to their own niches with different perceptions that best enable them to survive.  I don’t think it’s frightening that we don’t experience true reality, as some people have said.  I’d be more frightened to actually experience true reality, because my brain isn’t meant to perceive things as they really are.  It’s meant to perceive them in a way that is most helpful to my survival.

Cayla McNally's picture

Insanity and Standard Deviation

It was mentioned in class that insanity was simply 'one degree of standard deviation' away from what is considered to be 'normal'; however, the question that this leads me to is can there ever really be a consensus of what reality truly is? It is something that is so subjective, so foreign from one person to another, that there can never be any chance of finding an average or calculating standard deviation. This would also rely on the idea that all types of insanity are equal, which is clearly not the case, because there is no way of equating mild depression with severe psychosis. Another question that this line of thinking brought me to was: in a place where there is a higher percentage of people with mental illness, can the 'standard deviation' be considered the same? How does the concept of reality change with people of different states of mind?

JaymElaine's picture

I agree

I wanted to comment on this particular blog because I also agreed. I just had an earlier conversation with a friend of mine, and we discussed what it means to be "normal". What does normal mean, and how far off from "normal" makes you "crazy"? Are there like degrees of craziness?! The concept of reality that Cayla discussed does change from person to person, in my opinion. I mean, come on, we have 10^12 neurons in our brains, and each of us has a this large collection of neurons connecting and firing in different ways (this is what makes us so special, yay!). With all of this, I think that this leaves some room for differences in what reality means to us. This leads me back to my original question: with different concepts of reality and different levels of psychosis among us, how can we ever define what is and what is not "normal" and should the concept of "normal" even exist? I suppose society, with all its taboos and morals, will decide that.

Jayme E. Hopkins, '08

AriannahM's picture

I think there are very few

I think there are very few things we can ever really understand completely in life. One sure thing is consciousness. For me, my consciousness IS my reality. I would argue that you have to be conscious to have a reality, so these two concepts are interchangeable for me. I will never know if it is different from someone else's or if it is exactly the same, but I can count on it to be consistent. Although there may be changes over the years, my reality is always (generally) the same. I don’t think there’s any need to be freaked out by the idea that your brain is making up for what your eye isn’t actually see. It’s nothing new…your sense of reality has always been governed by this. On a tangent—has anyone seen the movie Waking Life? I think it would tie in well to this discussion about what’s real.

Sarah Harding's picture

I agree that there is no use

I agree that there is no use in worrying about the blank spots that the brain makes up for. For each person, reality is what they are experiencing, and it doesn't necessarily matter how "real' it is. However, it bothers me that each person might be visualizing things differently. How strange that we could be looking at the same the thing and seeing it completely differently. I really like the way that you descibed our sense of reality as having always been this way. I guess if there's nothing we can do to reveal the "true" and "universal" reality, we should accept that reality is actually composed of billions of versions of reality and consciousness. The reality of the situation is: to each person, what they are seeing is real. So maybe there isn't a universal reality, maybe the truth of reality is that every person's perceptions are true.

Student's picture

free will

A few days ago, the tennis coach here said something I thought was pretty interesting.  She told us that even if we weren't having the best day, tennis-wise, or otherwise, we could still will ourselves to win.  I started to wonder about that...if it really was true- or, less wrong.. and realized that it made sense.. that we could probably will ourselves to win.  I wondered though just how much control we have over this will... if we can will ourselves to get one more ball back than the other person.. if we can will ourselves to not just not lose, but to win.. what can't we will ourselves to do? I think we can only really will ourselves to do things we really desire.. things we have high praise for. But can we decide those things for ourselves? I'm leaning towards probably not..

emilie's picture

When you say reality, it is

When you say reality, it is necessary to define what exactly reality is. How can one really define reality? Who know what reality really is if each person's experiences and perceptions are different? It seems that there is no all encompassing definition of reality. Ane who really cares if the brain isn't organized to give a picture of reality if we are still able to function and what we see isn't causing us to have a diminished quality of life.

The visual system is more complicated than can ever be imagined. The majority of the brain is devoted to vision. There are different kinds of cells that account for every different aspect of vision: cells that "see" lines, cells that are sensitive to motion, ones that are sensitive to color, etc. All in all, I feel that the brain does a pretty good job of integrating all of these different pathways and kinds of cells into one complete picture.

RachelBrady's picture


            We’ve been discussing illusions as if they were abnormalities of vision, but how can we call something that is a universal and predictable experience of all human beings abnormal? When I perceive two lines slanted towards each other as going off into the distance, when they are in fact on the same plane, I am said to be manifesting an illusion. Whereas, if I consider two people, of the equal heights, to be the same height when one is standing up close and the other in the distance, my perception is not said to be illusory despite the fact that the latter projects a smaller retinal image. These instances force me to wonder which condition is the illusion and which percept is normal? Since both classes of percept are manifested by everyone, that is everyone perceives them in this way, isn’t it reasonable to classify both instances as examples of normal perception?

            Illusions are not something abnormal that cloud the “normal” perception of the real world. I would even go so far as to suggest that the perception of illusory distortions constitutes a clearly definable aspect of normal perception. Basically, any account of normal perception should also account for the perception of illusions, which should be analyzed as a part of the normal perceptual process and may serve as important tools in the study of visual perception.

Lauren Poon's picture

Your vision's fine

I really liked the blind spot test we did last week, but I never realized how large this spot was. I'm missing a large piece of scenery when I'm driving down the road. However, the brain fills in this spot with an educated guess of what should be there. What if there was some strange object floating around, like a plastic bag. The brain would not assume that the bag was there. Would I not be able to see it? Would other people see the bag because it's not in their blind spot? Is my sense of reality completely false? Should I be worried about driving my car this weekend?

These were some questions raised in class. Is our sense of reality completely different from others around us? How are we not crashing into each other? Luck? Actually, I'm not too concerned about driving my car or worried about my blind spot missing the plastic bag. I will definitely be able to see the plastic bag for numerous reasons. 1) My eyes are constantly looking around the entire road. My blind spot is constantly changing. At some point, I will be able to see a foreign object on the road. 2) The car is moving. As the foreign object moves closer to me, it moves out of my blind spot. I'll certainly be able to see it.

I don't think our sense of reality is that different from the image received in the eye. People tend to have the same perception of objects. No two humans are living and perceiving a different world. However, humans and other organisms are living and perceiving a different world because we have different sensory limitations. Every kind of organisms perceives reality to the best of its ability with the limitations it has been given.

eshuster's picture

Can we find a link? Or are we imagining it?

As I was sitting in class on Thursday, I heard something that confused me. Prof. Grobstein said, the brain is smarter than the eye and that is why we can see in 3 dimension when we only have one eye open. What puzzled me at first was his phrase. At first I thought. How can the eye be smart? It has no mind. How can we use that term when referring to the eye, but then as I really started thinking about it I could only question, what is “smart”? Is it the repetition of reading textbooks and regurgitating what we read on an exam? Is it free thinking? Is it the ability of the brain to control its action potentials? Is it as simple as being able to multi task or knowing several languages? What is “smartness”?

As I kept thinking about the question, I came upon more questions. I starting rethinking what I have been questioning all semester, What is thought? What do we do when we are thinking? What is going on inside when we cram for exams? Or pull all-nighters to get that one paper in on time? What is going through our brain? Not just thinking about action potentials but the differences between them? How do we interpret these movements? We obviously don’t feel the action potentials that generate our every movement? I don’t feel the action potentials in my fingers while I write this posting? So how do I know they exist? Is it like believing in G-d and having faith that it exists without actually delving into the hard core research?

  These questions rotate throughout my mind and continue to pile up? I think of the question posed last week, What is reality? How can we relate reality, smartness, thinking, and action potentials? There is a link, even if the link is that I’ve been thinking about these concepts throughout the semester. If being wrong is right in this class, then how do we define smartness? Is it a measure of how wrong you are? Is it a measure of how right you are? Can one measure whether something is wrong or right? How is there no answer to any of these questions. There are more questions? How is the brain smarter than the eye if we think of smartness as the thought processes of the brain? If the eye has no brain of it’s own, then what is the reality of smart? And oppositely, what is the reality of being dumb?  

What is the link between reality, smartness, action potentials and thinking? Is there a link or do we just imagine one? If we are talking about reality, shouldn't we mention imagination

alexandra mnuskin's picture

Babies, perception and the I-function

It seems to me that we have come to the conclusion that the brain fills in the blank completely without the aid of the I-function. 3-D vision, seeing the extra dot…all of it happens without our conscious thought. However I’m still curious about whether this is an innate ability or if perhaps it’s the sort of thing that must be learnt.

Jean Piaget, a famous developmental psychologist wrote that at birth babies do not realize that an object is whole if it is partly overlapped by another object. So for example if a ball is only half way visible behind a table—the infant will conclude that what he is looking at is half a sphere. It seems then that the infant’s binocular stereopsis is not quite functioning. Or rather that the story he is getting from his brain is not a very accurate one. He first has to be able to consciously realize that this is most probably not half a ball but a whole ball—one that he has seen and played with before. Can the brain then only fill in the blank with something it has seen before, something it thinks it recognizes? Are we then back to consciousness and the I-function?

kjusewiczh's picture

Seeing my dinner

I thought that the differences in sight that we talked about on Thursday was very interesting. The thought that we evolved different eye positions based on the food that we eat is fascinating. Rabbits eat grass. They don't need to focus on how far away their food is. Grass is everywhere, its pretty easy to find it. However predators are the more immediate concern for the rabbits. Thus there eyes evolved on the side of their heads so that they could see all around them. They don't need to focus on how far away the predators are, they just need to see that they are there. They way their eyes evolved is perfect for what they need. However we were made to be hunters. Our food is not everywhere, we need to find it and focus on it. Thus it makes sense for our food to be in the front of our face. We need to know the exact distance away from us that our food is. It doesn't matter so much where predators are because we don't have many. We are a predator. The evolution of the location of eyes seems to be one of the most sensical things that has ever happened. Herbivores need to see predators all around them. Predators need to focus on their food. The location of the eyes is what matters. And evolution has managed to solve the problems. I think that is fascinating.

LS's picture

Hunting down the cereal box

I know our eyes are where they are because we are/or rather were predators.  I guess we still are predators but a lot has changed I don’t need to hunt down my meat anymore, it comes nice and clean and vacuum-packed in the grocery store, I don’t have to capture it and I certainly don’t need to pounce on my box of frosted mini wheat to catch it.  So what I am wondering is if in Western society (there are still societies where humans are and need to be predators) how our eyes will or are evolving.  Granted it would be pretty ridiculous to see a person with eye balls on the sides of their heads, and I know a change in a eye position would bungle up our brain’s visual system so bad it makes my head hurt --- yet is it possible?  Yes we do hunt animals etc. but they are on farms and are so domesticated that so we still count as predators, do we really need to watch out for them?

urbrainondrugs's picture

Daz cool

Based on the topics we covered in class last week, most of the things we see contain gaps that are filled with an informed guess by our I-function of what should be there. Because there is such a high level of variability there are different interpretations of reality. Our systems reduce levels of ambiguity, however they are still there and necessary. Different perceptions of things is very important, especially when it comes to solving a problem. Two heads are better than one, not only for the combined thinking power, but also because one person can see something different/differently than another, opening up more pathways to an answer. So when people say, "We just don't see eye to eye", are they really not seeing the same things? And does this type of variable perception apply to the way people think as well? Is the i-function's ambiguities responsible for things that are considered creative and inventive?

James Damascus's picture

The Crisis of Representation

If we assume that all modes of representation are indexical to ideal forms (in short, the things represented), then there will always be an intellectual crisis of representation. While this issue is taken up most clearly in Western semiotics’ obsession with perception, signs, and objects-themselves, I think the Mary Jane example does well to apply this issue to neurobiology. In short, there is a gap between some theoretically-abject reality (a series of wave frequencies) and a sign or perception (magenta) experienced by an observer. The dilemma of light waves vs. perceived colour is map-able to the disjunct between collections of sound frequencies and the singular sounds we perceive in their place. In yet another physics experiment, we used computer software to break our voices up into their unique frequencies and then reproduced the sounds of our voices by combining those same frequencies. We also were able to reproduce the sounds of instruments (clarinet, violin, cello) by combining their characteristic sound frequencies. If we consider the objects-themselves, we did not actually hear voices or instruments, even though the sounds we perceived were indistinguishable from the sounds produced by actual instruments and people. More generally, the unique singular sounds we attribute to point sources actually are made up of a number of different sound frequencies. That said, one might ask whether perceiving eleven distinct sound waves is in some way more authentic than converting these signals into the distinct sound we hear when a clarinet is played?

To some extent, the indexicality of signs is an issue best taken up by philosophers, linguists and anthropologists. I was reading through a couple articles written by anthropologist Stephen Tyler (not from Aerosmith) and linguists Peirce, Saussure and Whorf. If you are interested in these, please let me know- I do not have access to a scanner at the moment. While Tyler uses the issue to criticize anthropology (not directly relevant), I think his conclusion may be useful to us (‘there are always gaps in our knowledge so don’t worry about it’).

Commenting on sign systems and ideal forms, identifies the indexicality of science (and, by extension, ethnographic description). Tyler recognizes the limitations of epistemology (Peirce’s notion of the sign is deceptive since the third element-the represented object- never fits inside) and suggests that the represented objects have to be considered with descriptions of the things to which they are connected. In one sense, this move indicates that objects (or ‘percepts’, sticking with linguistic terminology) have thickness or thinness, as described by Geertz. If one is representing ‘Lisa’, for instance, they are representing a person whose life connects in complex ways with the lives of others. What this means is that it’s impossible to know the ‘true’ Lisa. In other words, there are limits to what we can know (gaps in our knowledge that cannot be avoided).
In recognizing that representation has shortcomings, Tyler does not seem to share the anxiety of other scholars. In a way, he’s responding to anthropology’s suggestion that we can know other people objectively (in the manner claimed by science). His cure to the gaps in knowledge mentioned above is hermeneutics; He proposes abandoning epistemology and embracing hermeneutics since the gaps in our knowledge are an unavoidable part of life. So what Tyler wants to do is make something concrete. An ideal postmodern discourse, he thinks, will reject the western obsession with the separation of perception, signs, and objects. Philosophy will thus close the gap between words and action: in short, there will emerge a discourse that has done away with what Peirce establishes as the secondness and thirdness of representation itself. Sticking with Peirce's terms, one can say that the world would thus become an icon where it and language would stand in a relation of pleonasm with each other. In the language of Peirce, it would only focus on the sensory-perception, or the firstness of language. The chief advantage to eliminating the idea of representation is that it would "show there is no problematic relationship between word and world, for both are mutually present.” The desired object of “evocation”, as described by Tyler, is the recognition of the commonplace or commonsense of a particular community. As a consequence, it would constitute a discourse without universals, and without the damaging pretension to "general knowledge."

Linguists (substitute in ‘sensory imaging’ or ‘sensory perception’ for ‘language’, and their arguments become relevant):

The theories of Ferdinand de Saussure, Charles Peirce and Benjamin Lee Whorf all focus on the relationship between language and culture. Functionally, the systems share a single thematic focus on language and sign systems as mediators of experience, communication and thought. They differ to the extent that they offer dissimilar explanations for just how sign systems mediate thoughts, experiences and communication.
Perhaps the most well known of the three theorists is Ferdinand de Saussure, who examined the basic elements of language in relation to their functions rather than in relation to their causes, as had been the commonly accepted approach to language study up until that point. For Saussure, the scientific study of language ideally focuses on the linguistic “system” rather than the history of linguistic phenomena. In analyzing how language mediates people’s experiences, Saussure employed the concepts of sign (the combination of concept and sound image), signifier (sound or word), signified (the implied concept or thought), arbitrariness (the idea that the meaning of a gesture or word is not intrinsic, and must be agreed upon by the linguistic community) and structure (a system of language). For our purposes, Saussure’s theory of language and culture is significant in that it suggests a connection between ideas and language, and identified the link between thought and sound. Language, then, is a system of signs that express ideas much like a system of writing. A linguistic sign is a two-part item made up of a concept and a sound-image that recall one another. This combined item is also referred to in terms of a signified and signifier.

Peirce takes Saussure’s intepretation of language as a sign system and complicates it both by identifying multiple types of sign systems (of which language is one specific example- visual symbols are another) and analyzing how sign systems function. For Peirce, there are three fundamental components of signs- iconicity, indexicality, and symbolicness, all of which characterize the link between the object and the sign (or “ground”- the way in which you determine what a sign represents). Indexicality refers to the extent to which a sign points to something. Cursing, for example, may index, or point to my frustration (“shit” indexes frustration). It also represents a degree of conventionality; that is, cursing is seen, through convention, as a way to express frustration. Further, cursing out of frustration may be iconic in the sense that the way one pronounces the curse word expresses the feeling that person is experiencing.
Signs, meanwhile, include both those occurring naturally and those that are manmade. Peirce expanded his analysis to look at the degrees of reality a sign can have. He characterizes this in terms of firstness, secondness and thirdness. Firstness is a quality (like a color) immediately perceived (something that strikes you right away). Secondness is described best as a relation or relations between reactive objects. When you observe an event, for instance, you are witnessing two things reacting to one another (ex. grass reacting to wind) or, in other words, a relation between two things. Thirdness is a general rule or convention. In a general sense, Peirce’s theory relates to the other two theorists we’ve encountered (Saussure & Whorf) in that it suggests that all of our experiences are mediated in some way by signs (and, by extension, language).
Like Peirce and Saussure, Whorf suggests that language is a mediating force in people’s thoughts and experiences. According to the Sapir-Whorf hypothesis, the relationship of thought to language is one of channeling. In other words, language influences how people think about the world. This coincides with the theories of signs proposed by Saussure and Peirce, both of whom support the notion that language mediates how people experience the world. In some sense, all our experiences are mediated.

eden's picture

I see dog people...

I was thinking about “reality” and how we perceive it, and I wanted to be fair and look into how other organisms perceive it too. In my perusing found a very interesting National Geographic article about dogs trained to help people with seizures. Here’s an excerpt:

“How dogs detect an oncoming seizure in a human is a mystery. Some trainers and researchers think they detect subtle changes in human behavior or scent before an episode occurs. There are no scientific studies, however, to prove these theories…Since 1996, the nonprofit organization has produced well over 25 seizure alert dogs that warn 15 minutes to 12 hours before an attack. The dogs exhibit attention-getting behaviors such as whining, pawing, or anxious barking.”


Now, I’m a science-type girl, but every once in a while I like to step out of my box and let my mind be a little bit flexible. I find the concept that dogs can “sense” a person’s aura or whatever, very fascinating. As a dog owner myself, I admit that I have noticed my dogs responding to my emotions before I even let them show. Let’s say I’m sitting on the couch and I feel really depressed or something, but I’m trying to ignore it by focusing on the Price is Right. Whereas usually my dogs keep to themselves, 9 times out of 10 if I’m feeling low one or both of my dogs will come over and put his/her head in my lap, or lick my hand or paw at me, and try to snuggle. I wonder sometimes how they know how I’m feeling. Is it a change in my behavior? Well, there really isn’t much variation involved when one is watching TV, it’s a pretty sit and stare routine whether you’re depressed or not. Or is there some kind of “aura” that human beings are not capable of “seeing” or sensing because we don’t have receptors for it? It’s not outside the range of possibility. Dogs usually make pretty accurate judgements about people too. Like, if I guy walks into my house and my dog starts growling or runs away, I put a lot of stock in that cause chances are he's a creep. Conversely, ALL dogs INSTANTLY love my uncle. He doesn't have to do anything but come through the door. Why is that? And what about babies? I love babies, and I have totally noticed that a baby can sense when a person is not comfortable with babies. They get all fussy and annoyed, even if the person is just nervously holding them. The baby can’t really comprehend the person’s words if they SAY they don’t feel comfortable, and even if the person isn’t doing anything but standing there holding the baby, the baby just senses the discomfort and gets upset. On the other hand, my brother might walk in to a room where I’m crying and not even notice. I mean, aren’t our brains so much bigger and cooler than dog brains or baby brains? Yet I wonder if our big, cool brains make us miss stuff by ignoring signals a bit TOO much, or rearranging the hierarchy of what is important when it comes to input. When we are walking down an empty street alone, do we trust our eyes or our “gut” as to our safety? Which SHOULD we trust? Maybe we really can sense emotions or “auras,” but we teach ourselves to ignore the signals because they are subtle or not easy to define. I mean, sometimes couples who have been together for a long time seem to be able to sense each others emotions pretty accurately, maybe because they are so focused on each other that they don’t ignore the little things that might usually get edited out.

It just strikes me that we often focus so much on thinking, that maybe we forget about the power of emotion… that is, if you believe that emotion exists apart from being a thought process. Haha, like I said, it’s hard to define.

Antonia J's picture

aura colors?

I have to agree with Eden that it is interesting what our brain edits out, and if that really is an asset.

A few months ago a friend of mine started rambling about auras, and about how he could see them, etc. I pretty much told him that he was talking crazy, but being in this class has made me question my original reaction. Maybe people really do have auras, maybe even auras that are made up of certain colors. Maybe there are some people who have the ability to see them, kind of like the way dogs sense emotions in people, like Eden was talking about. It's really not that impossible once you start thinking about all the things the brain does edit out...

And then, of course, I start wondering about 'psychics' and people who can 'see ghosts', ideas which I readily dismissed before. I'm not a science major, but I am a very down-to-earth person... I like to have evidence about everything, I like things to be pragmatic and, well, very cut and dry. Every once in a while I take a moment to think about all the fantastical things that may or may not exist, but usually I just focus on what I can see and smell and hear, rather than what I might be missing out on.

Basically, this class, by making me question reality, has made me a little more open to the idea that people can hear, see, or sense things that I may not be able to hear, see, or sense. I'm a bit ashamed to say it, because I really do like things to be clear, "experimentable on", etc. But maybe this is good... maybe I'll start looking into subjects I would otherwise have ridiculed.

x's picture

Brian Auras?

It's funny that you mention auras, because (for fun and laughs) I went to a psychic on south street this weekend and had her "read" my aura. It was fascinating the way it went down - she just looked at me and around my head and immediately started talking. She only spoke for a few minutes (and everything she said seemed mildly true, in a universal kind of way), and I wasn't really convinved that she knew what she was talking about, yet somehow wanted her to keep going. I really wanted to ask her if she was full of crap, or if she was real.

Is there ever going to be technology to analyze the brain of psychic people and see what chemical reactions are going on in there? Is it possible that they just see reality differently, and that doesn't give them "powers," per se, but just a different view of the world that they can exploit to make some fast cash? If examined, would her brain itself be fundamentally different from mine? What would her brain's "aura" be? 

A.Kyan's picture

I'm Okay with Gaps

In 1957, Walter Penfield established a map of the human body in the brain.  Different areas of the cortex were assigned to process different areas of the body.  A study carried out by researchers at Vanderbilt a few years ago found the cortical map to be a reflection of our perceptions, not the physical body.  When we experience illusions like we did in class, we think we’ve been tricked.  Research conducted by Roe, et al., claim these illusions are a result of how the brain is organized to process all the info it receives from our senses.  Roe's research used the tactile funneling illusion to explore how the brain processes touch.  An individual perceives simultaneous touches to multiple locations on an area of skin as a single touch at the center of that area. "The brain is reflecting what we are feeling, even if that's not what really happened."  It seems the brain is integrating sensory activity based on its circuitry. (

Since learning our brains have gaps/holes and that it doesn’t relay authentic information, it doesn’t surprise or bother me.  My take on it is that the brain has become more efficient by having these gaps.  If you don’t need it, why have it?  Referring to the physics lab with Mary Jane (I’m in that torturous lab, too) we learned that we only have 3 colored cones in our eyes (made up of red, green, and blue).  Yet this simple combination of 3 colors allows us to perceive all the colors in the world.  Why clutter our eyes with a gazillion colored cones when we don’t need them?  Who’s to say magenta isn’t a real color because we don’t have the corresponding anatomical part to sense it?  To Mary Jane, magenta isn’t real because she’s just a computer and doesn’t have the cross-wiring like we do to make complicated, integrative connections.  Maybe we’ve become so evolved that we can process information without having everything spelled out.  That doesn’t necessarily mean we’re making false conclusions, it may just be that we are more advanced than we thought, and yes, better fit for survival.  Which is why technology may be emulating us in the realm of TV screens and LCD lights.  TV screens are made of the same 3 colors as our visual cones to produce all the images on our favorite shows and movies.  Ever notice the AMTRAK building or Boathouse Row along the Schuylkyll River?  Those LCD lights only consist of the same 3 colored bulbs as our eyes to produce all the great colors and patterns they display. 

I’m inclined to believe that our brains don’t give us a play-by-play of reality because it’s not necessary.   Instead, our brains give us a nice summation of what’s going on around us through an evolved circuit of cross-communication among the senses. 


Sarah Powers's picture

Creating the Constant

In lecture on Tuesday we discussed that the sensory system of the brain really only processes transitions from one state to another.  It takes in the transitions from the white squares to the black squares on the checker board, but it the brain activity is the same at the middle of one of the white squares and one of the black squares.  Basically the brain is filling in the blanks. Creating the constancy between the transitions.Wow. Our brains make a lot of stuff up for us.  It must be easier to infer the realities between the transitions than to try to actively process those interum inputs.  I don't really have a problem with this. The interpretation my brain is doing has served me well thus far. I don't run into walls because I don't think anything it there. I run into walls because I don't watch where I'm going.I think the brain makes up the constants because it's easier that way.  There are less inputs to process than if you were to try to make sense of every single input that came into the nervous system.  The brain focuses on the most important parts--the transitions.  Changes in the environment are more important than the constants because they give you new information, more information.  Evolutionarily speaking, this is advantageous--to find prey or avoid predation. The problem I have is with the variation from person to person.  If we are all creating our own constancies in our own realities, there is a lot of room for variation.  But there doesn't seem to be that many differences  in the observation of 'reality.'  Does the blue that I see look like the blue you see because we were both taught that that specific wavelength of color is called blue? Or are we truly experiencing the same color?I believe our realities are the same from person to person--or so it would appear. Maybe, the variation is in the different interpretations.

Holly Stewart's picture

Reality as Reflective

I’m not sure we are right on in thinking that the brain doesn’t give a picture of reality. This conclusion may stem from the fact that we have now realized that our brain isn’t giving the picture of reality in the way we thought we were getting it, but that doesn’t necessarily mean that we aren’t getting anything at all. Maybe our discomfort is from the fact that things aren’t as simple as we want them to be. In our previous conception about what the brain does is fairly simple: we see something empirically and then our brain flips the image from our eye and volià, we have reality! Knowing what we now know about the complexity of the nervous system, it doesn’t seem that surprising that we will have to replace our idealistic conception of how the brain presents reality.

Initially it seemed a bit surprising and somewhat disconcerting about the amount of information the brain is filling in. But now I am starting to look at brain from a different perspective and it feels a bit more comfortable. We have a visual system which has a lot of communication and interpretation in and of itself. Furthermore, this visual system is set up to see sharp changes in points of light which not only allows us to see depth, but also to distinguish one object from another. Our visual system also has a check-and-balance aspect of its system: there is a part of the visual field which is seen by both eyes. I think there is a good reason for this which ties back to evolution and looking at humans as animals. There are many different ways that our visual system does the same thing, but it is the ability to combine this information that is really important. Each of our sensory systems in our body must have an understanding of coherency to create reality the way it does. This creation of reality isn’t random. Yes, I think that it is appropriate to think of reality as an average with standard deviations, but the honest truth is that most of us see close to the average.

I don’t want to purport reality by consensus, so for all intensive purposes I assume that we are all actually seeing/experiencing reality around the average, with our own subjective interpretation of sensory information. We all get a consistent picture of reality with our experience: when we reach out to touch something we can. And when it comes to the brain filling in information, it is a good thing that we have set up the world around us which supports the way that our minds work. In some ways I think it isn’t really necessary to consider what the world is like outside of our experience of it, since that is really all we can know (Kant also takes this viewpoint). The point is that we experience reality and our brain experiences reality the way it is for us. And it is designed to give us the picture of reality that has been advantageous for evolution (which I will discuss in a minute). There are reasons for the way reality appears to us and there are reasons for the way our brain presents the picture of reality the way it does. I can’t say that I necessarily know what those reasons are, but I do know that it is working out alright and has been for a couple million years.

Evolution. The visual aspect of our sensory system is set up to respond to change. This seems logical considering our animalistic background. If the most fundamental aspect of life is survival then we want to be able to respond to changes in our environment and then make a judgment as to whether those changes warrant any sort of specific response. I believe this has to do with the (arguably) instinctive “fight or flight” mechanism. Over time our brain is able to interpret patterns of signals and determine what kind of response is needed. Reality for humans is change itself, since that is the aspect of reality we are tapped into. Reality is the language that reflects networks in the brain, and the brain is presenting the only form of reality is designed to interpret. The brain should not be seen as presenting a different picture of reality, rather it is simply presenting a narrower, more selective form of reality than what we traditionally believe we are experiencing.

Pleiades's picture

Mary Jane (the computer)

So I was in physics lab a few weeks ago doing the lab on optics. We were looking at different colors and were told to interpret them as a human, and then pretend as if a robot named Mary Jane was receiving these colors as an input as well. The way we see color and the way MJ ‘sees’ color, as a computer is vastly different. To us any color not in the spectrum (ie. Magenta) is our brains interpretation of a combination of signals from cones that are activated by wavelengths corresponding to colors that are in the spectra. There is no wavelength for light that is magenta (there are really only wavelengths for red, blue and green). Basically when we see magenta, the signals coming in to activate the cones are purple and yellow (I think) but our brain says ‘oh that’s magenta’. MJ, on the other hand, just sees the wavelengths that correspond with purple and wavelengths that correspond with yellow. The lab went on to push us to diagram how MJ would see a lion and a tree. We, of course, see yellow and brown and green and say, ‘oh lion’ run or ‘oh, tree’ picnic. What MJ sees is different wavelengths corresponding to light of those colors, but they are not integrated as we do. I think that some of what the lab was getting at (from a neurobio. standpoint) was our brain is at first similar to MJ’s, we just get in the same wavelengths, but then, unlike MJ, we combine this information to consolidate it all. Perhaps this is a coping mechanism for our feeble brains to be able to deal with the enormous amount of sensory input. If this is true, perhaps it is from an evolutionary advantage that we don’t ‘see reality’. I still think it is for the best and reality is only what we are able to see anyway, so get over yourself Plato. Trapping yourself in your cave is making you miss out on reality.  

katherine's picture

Seeing is believing

In class we looked at the pictures that had more than one image in them.  Initially, some people were able to see the skull or the woman, but eventually everyone was able to see both.  How?  This concept reminds me of an article I read a few weeks back about face recognition.  The article discussed humans' ability to see faces in non-human objects such as clouds, potato chips, the moon, etc.  Now knowing about how we are able to fill in missing pieces in our vision to make a complete picture, this article makes more sense to me because I now know that people.  It also made me think of all the times that we try to associate objects with something with which we are familiar.  For example, when you're looking at clouds with someone and they point out a cloud that looks like a certain object to them, it might take you a second to see what they are seeing.  However, after you've looked at it in a different way or they have explained it, you're usually able to see what they are talking about--the same thing happens with the picture of the woman in the mirror and skull.  It is amazing that our brain is able to see things in multiple different ways. 
But do we just assume that everyone is seeing the same thing or are we all really seeing the same thing?  Perhaps we all just think that we are describing and looking about the same thing the same way; it is only until a picture such as the skull/woman is presented when the difference between what we see comes out.

Aditya's picture

Skull vs. Woman / 3d from 2d

To me, it was interesting to see that some students when presented with the same picture effortlessly saw one image, while the other students effortlessly saw the other image. I asked myself, why is it this way? When I looked at the picture of the skull/woman looking in the mirror, right away I saw the skull, and when the picture was re-presented, my vision adamantly still saw the skull. I had to use a lot of my cognitive and mental resources to see the image of the woman in the mirror while other people saw the woman effortlessly and instantly. Once I was able to see her (after some time), I was thinking to myself, how I could I miss the image of a woman's face that made up the skull's eye? To these questions I will pose a series of thoughts/hypotheses.

 When we saw these images, we had to categorize whatever we saw as skulls or mirrors and reflections and women. We have this knowledge in our memory of what a skull is, what a mirror is, what a mirror does, to make sense of the picture. But what if as a society we were never exposed to the image of a skull, or what it does, where it is located etc. Because we knew what it was we were able to recognize a skull, but if we did not know what a skull was, we would have just seen a pattern of colors and shading. We can deduct from this that what society and culture we grow up in, will act as a lens, for what we can interpret, what we can make sense of, when images are posted on our retina. The process of viewing these images or any images in general is very complex and also includes cognitive processes that requires us to process what we see, categorize it, think about it, make sense of it, all in mere seconds. This is another humble and amazing ability of the brain that I wasn't really conscious of until recently. Also, not only did I see the skull, but in order to do so, I succesfully ignored images of the woman's face, without my "I" function realizing it. It is as if the other side of the nervous system independent of the "I" function decided to zone in on the skull and ignore the woman's face. Why? I don't think there is any single answer to this question but a series of factors that vary from picture to picture such as which was is white which one is black, which image is more simple, with less edges, which one is more complex. However something important that I realized was that while looking at this image, I ignored certain aspects of it in order to see the other without realizing it. This could be happening in the day to day bustle of our everyday lives and we would not even realize it.

This of course spawns new questions. Is this ability effortlessly  see the skull, or see the woman, or some who see both and not ignore anything genetic ir hereditary? Is it learned or acquired through different experiences of the culture or environment? Did I just see a skull because in my life I saw more skulls than woman looking in mirrors?

  Also some rules were listed about how we can make 3d stories from the 2d images on our retina. Recap: horizon assumption, parallel lines vs. unparallel lines, interposition, relative size. My question about this is that are these rules learned from experience or innate? From our lives, we know when one thing is in front of something else interposition occurs. We know when objects move away they get smaller. The point is we know these rules from experience in reality. But what if you showed a baby that was just born, who hasnt opened his eyes yet, a painting? Would he or she be able to tell from interposition, relative size, horizion assumptions or parallel lines, a 3d story from this 2d image he or she is looking at? Since we can't communicate in detail with babies this is not possible. Is there a way to tell whether these rules are innate or if they are learned from experience?

biophile's picture

How real is reality?

I'd like to think that the picture we have in our heads at least resembles reality. After all, how could we survive in the world if it didn't on some level? If I see a lion running towards me in the distance, I'm not going to just stand there and wonder if it's simply a product of my imagination. I'm either going to run around in circles hopelessly or actually do something to save my life. Even if the picture I have of the lion doesn't completely capture its presence (I can't feel the vibrations it causes in the air or smell the hormones being released into its blood stream or see it in hyper-dimensions, insert other techno babble here, etc), it's enough to know that this is A Very Bad Thing. The brain didn't evolve to enable us to see all of reality. We just need a sliver of it if we want to live long enough to produce the next generation.

Don't get me wrong. It's fascinating to see in what ways we're limited and how our brain tricks us into believing that we can perceive everything around us. The things we talked about in class (how we see walls and checkerboard patterns; holes in our vision that are covered up) are neat little algorithmic tricks our brains carry out just because it's a convenient way to process information. It's amazing to think about, how there are really so many different ways to process information in systems. I for one would never have thought that our brains registered changes in brightness and then colored in the area between change accordingly.

It's really cool to think about for its own sake and it's also really handy to study for practical applications, e.g. in engineering, systems management, etc. After all, what experimental lab is better than the world around us? Nature is the ultimate experiment because the designs we see today have been around for millions of years and have been tested under divers conditions. The study of complex biological systems have far-reaching implications for electrical engineering and communications, for instance. We can find the most efficient design for new developments in technology by looking at what has stood the test of time.

I'm getting off-track, but here's my point: the reality we each experience is a subjective thing. One of the main goals of science is to detect and study the patterns underlying our collective perception of reality in order to see how things work. I hesitate to say that there is no such thing as reality, though, because there are certain things that are just true and we can't get around them. 2 + 2 will always equal 4, even if you use different words for it. The laws of physics and math are true, even if there are new discoveries being made on astronomical levels and in quantum mechanics. The motion of pendulums, the firing of neurons, the synchronization of bodies, the algorithms in computer programs, metabolic cellular functions- they all follow these laws and they can be accurately modelled according to these laws. Outside of this cerebral area, though, I'd say that reality is up for grabs. Let the uncertainty commence.