Week 10 - Neurobiology and Behavior

I like the idea of ability and disability being viewed in evolutionary terms. What we see as "ability" today is simply  what we have been selected to do most efficiently. As a species, we walk on two legs. Someone born with just one leg is at a serious evolutionary disadvantage, and is therefore marked with "disability." Of course, I'm not saying that a person with just one leg is unable to live a fulfilling life-- we know that in today's technology based world, this is not true. But in evolutionary terms, this person is not fit, and therefore will not be successfully producing offspring for upcoming generationgs. I think A.D. has an interesting idea when he says that in the future, maybe what we are today will be considered "disabled." Just food for an evolutionist's brain, I suppose.

Can you read this?

 fi yuo cna raed tihs, yuo hvae a sgtrane mnid too. Cna yuo raed
 tihs? Olny 55 plepoe out of 100 can.  i cdnuolt blveiee taht I cluod aulaclty uesdnatnrd waht I was rdanieg. The phaonmneal pweor of the hmuan mnid, aoccdrnig to a rscheearch at Cmabrigde Uinervtisy, it dseno't mtaetr in waht oerdr the ltteres in a wrod are, the olny iproamtnt tihng is taht the frsit and lsat ltteer be in the rghit pclae. The rset can be a taotl mses and you can
sitll raed it whotuit a pboerlm. Tihs is bcuseae the huamn mnid deos not
raed ervey lteter by istlef, but the wrod as a wlohe. Azanmig huh? yaeh
and I awlyas tghuhot slpeling was ipmorantt! if you can raed tihs
forwrad it.

My sister sent me this E-mail and I found it fascinating that I could actually read the message with absolutely no trouble.  It reminded me of our discussion of how the brain fills in the blind spots of our visual system.  I guess this is evidence to support the idea that the brain fills in more than just the blind spot where the retina has no light sensitive cones. 

I searched around the internet for the actual paper written on the study but I was unable to find it.  What I did find were multiple websites proclaiming that this “Cambridge University research” was actually just an urban legend.  Even if there is no scientific research behind this, I still find it amazing.  How did our brains get so smart?  I wonder if young children who have just learned to read are capable of reading jumbled words or if it is a skill one acquires after years of practice.  I have a feeling that children would not be able to comprehend the jumbled words because they tend to read phonetically –that is, they sound out the words letter by letter.  However, at a certain point we are able to look at a word as a whole and recognize it, its sound and its meaning.  But what if the words were taken out of context?  Would we still be able to recognize them?  I have a feeling that would not be as successful if the words were taken out of context.  In the example of the blind spot in the eye, the brain fills in the spot according to what is around it, so I’m thinking syntax is important when attempting to fill in the blanks of words.

How does this relate to our discussion of color and reality?  In reality, the letter combination “blveiee” is not the same this as “believe” but when you surround “blveiee” with  “I cannot blveiee that you just punched me in the face!” Our brains tell us (or most of us) that it has the same meaning.  I suppose this can be likened to wavelengths, cone activation and color perception, in that many combinations of the same letters are perceived as having the same meaning as long as the first and last letter are the same.  Similarly, as long as the same ratio of long and short cones is activated we will perceive yellow.

I’ll do more research and post again soon, but I just wanted to put this out there for everyone to think about!

I was thinking about the whole idea of reality and perception in relation to phobias. People with Schizophrenia etc. have issues with distinguishing between things/people that are real and things that are not, but that is only one end of the spectrum. On a more everyday level people have different fears of little things, fears that may be based on their perception of a situation, the way that they interpret something. Most of the time these fears aren't really there at all. For example, I have a big fear of geese based on an encounter with a goose from when I was little. At the time the goose was big and I was small, but now even though I'm older and bigger, I'm still afraid of them. The fear memory from that experience is etched in my memory. When I walk past the flock of geese by the pond behind Rhoads, I have a different experience than my friend might have because of my fear. In this case we are perceiving the same reality, the reality of the geese, but my reality of the situation as a whole is different because of my memories and fears, therefore the physical response my body has to the experience is completely different than if someone else was to walk past the geese.

I was very intrigued by the notion of color not being an exterior property, but rather something that we internally construct, inevitably in our own different ways. In class, we discussed the ways in which wavelengths and photoreceptors play a role in the interpretation of color, and it was mentioned that color is different across populations. However, I can’t help but wonder what role experience plays in the interpretation of color. It seems to me that perceptions can be influenced by expectations, and that these expectations are direct results of our previous experiences and beliefs. Obviously there is information that is ‘feedforward’ (from the lower to higher regions of the nervous system and brain; photons reach the retina, which then sends information to the primary visual cortex and then gets transferred to a region of the brain which recognizes color, etc), but there is also inevitably information that must go in the other direction, from the ‘top down’.

  This, then, introduces us to the idea that what you see, as well as what you hear or smell, is determined primarily by a framework of experience. This might explain the effectiveness of such methods as placebos and hypnosis. These things more or less allow ‘top down processing’ to overcome and influence ‘feedforward’, essentially recreating our ‘reality’. Recent brain studies of people who have been hypnotized show that it can change what people see, hear, feel, or believe to be true- brain imaging has shown that people were able to ‘see’ colors where there were none. This reinforces the ambiguity of the nature of our ‘reality’, in the sense that what we see and feel can be manipulated, but also raises the question of whether or not there ‘insanity’ is an objective term; if our perceptions can be so easily altered, and if everyone’s perceptions are different simply based on the fact that not everyone’s experiences are the same, then there is no real perceptive norm, and mental illness is simply a deviation rather than a reality.     

It's somewhat misleading to compare evolutionarily distant species' morphology without accounting for their respective evolution. In short, it's inaccurate to label Mammals  more or less complicated than other vertebrates based upon the number of cones they possess, just as it is misleading to develop evolutionary relationships for all species based upon singular criteria (ex. humans are more closely related to ants than to cats because cats have tails while ants and humans do not). Mammals and the "general pool" of vertebrates have distinct evolutionary histories that may better account for differences in eye anatomy than a complex/primitive definition (group A has more cones than group B because they are more/less complex).                                                                                                                                                                                                      Very good review of the evolution of color vision: http://www.optometrists.asn.au/ceo/backissues/vol87/no4/3268              Mammals diverged from other vertebrates approximately 300 million years ago, so roughly half of their history as multi-cellular life forms comprises independent evolution. Over subsequent millennia, Mammalia has evolved into its ~4,600 species. Paleeontological evidence suggests that early mammals were small and nocturnal. This basic nocturnality has had a profound impact on the nature of mammalian vision. Unlike other groups of vertebrate, the retinas of the vast majority of contemporary mammals are dominated by rod photoreceptors. In addition to a dramatic alteration in the mix of rods and cones, there have been conspicuous losses of potential color vision mechanisms. For example, the colored oil droplets that characterize the color vision machinery of many birds and reptiles are missing from mammalian retinas and two of the vertebrate cone opsin gene families are not represented in placental mammals (SWS2 and RH2) having apparently been lost in the evolution of this group. This reduction in the number of potential cone photopigment types and the loss of an important source of selective spectral filtering has yielded greatly simplified color vision in mammals.

I think I am convinced about the idea that individuals each have unique perceptions of color. Even before taking this course I have wondered whether color is perceived by all in the exact same way. But now I don't feel like I have to wonder about that anymore because I am leaning towards the opinion that color is a construction of the brain. This makes me question the idea of emotions that are associated with color. Advertisements often use specific colors to invoke certain emotions from their target audience members. For example, reds and oranges might be used to excite the audience but if we perceive these colors differently from one another how can they stimulate the same emotions. Maybe it comes from the descriptions we apply to colors. Reds and oranges are usually described as bright and warm. This may be part of a process of socialization that leads to many people sharing sentiments about certain colors. I should also recognize that I'm thinking about this from an American perspective. In other cultures different emotions might be associated with reds and oranges.

On a different, but hopefully related, note I've thought about the idea of "disabilities" as we term them. An example mentioned in class was color blindness. It can be viewed as a difference and not necessarily a disability. It is only a disability when placed in the context of an environment that leaves a person with that difference at a disadvantage. I've also thought about my ADHD which makes it hard for me to block out noise distractions sometimes. I personally see it as a disadvantage to me but I find it interesting that I feel more sensitive to a type of sensory input than the average person. So here we have one disabillity, color-blindness, that limits input and another that fails to ignore some unwanted input. Both of these are "disabilities" but for different reasons so it seems like "disabilities" could be a social construction. People who sense inputs in ways that deviate from the average are said to be disabled. But where do we draw the line between disabled and different?

I asked this question in the last class but I don't think it was ever really answered. When we discussed color, the general belief came to be that there is only color if someone has the appropriate photoreceptors that can be appropriately stimulated. If the tree falls and no one is around to hear it, there is no sound- then if no one sees a color, there is no color. (?) If this is so, then why are colors so important- particularly as warning signs? In nature animals and plants that have a red or yellow/orange pigment, like frogs, butterflies or certain plants, are generally considered or perceived to be poisonous not only by humans but by other animals. If colors are only a creation of photoreceptors and our brain, then why are they used to signal harmful toxins and protect certain animals throughout nature- not just to humans?

I do think about perception a lot and have been even before this class.  I think my thoughts are more scattered though.  For example, colors.  I feel like it is obvious that we do not all see the same colors, however how different are they?  Are we referring to hue differences or really large differences?  Maybe my sky is the colors of your grass and visa versa, however due to the way we are raised we all call that hue of the sky blue.  Although we do know that we are not really seeing “real” colors, it’s just the way our brain interpret wavelengths.  Maybe this accounts for preferences and why we all answer that age old question “what’s your favorite color ?“differently.  Maybe these differences in interpretation in our nervous system account for preference.

When we first learned about reality and the little disappearing dot trick I though I would be more upset about the fact that my brain in making things up, or that I am not experiencing everything.  However, the more I think about it would be really horrible to be bombarded with all sorts of crazy signals if we all experienced this we would probably just throw up and go to sleep (since this is how our brains like to deal with things!)  I am really amazed that our brain is making up part of the story and I think it’s a mixture of awe and respect.  There is so much going on and under the control of the brain I am just amazed.

However in terms of the tree in the woods question, I do think that if no one hears the tree it doesn’t make a sounds, but this gets trick in other cases and makes me uneasy.  For example when I leave my dorm room in the morning when I close the door does my dorm room cease to exist because I no longer attend to it with my visual system?  I have a hard time believing this, I just do not know why.  Maybe it is because I perceive it with my mind.  When I am not with my friends they still exist even though I am not “seeing them” right…at least I think so!  This happens with people who have died technically they are not still here but we still are perceiving them and remembering them…what does this mean then?

When we discussed color in lecture, we said it was a property of our brains and vision and not a physical property. I’ve been thinking about that all week every time I see a vibrant color and something isn’t adding up for me. A couple of weeks ago in organic chemistry we were talking about color. My professor said color is the result of hyper conjugation. Conjugation is when there are double bonds every other bond. When there are multiple conjugated structures put together, the structure is said to be hyper conjugated. This puts the π orbitals close together. The proximity of the orbitals allows visible light to promote electrons which in turn causes “color”. To me, this is a physical property; compounds that are colored are actually hyper conjugated. I understand we only experience the colors because of the way our vision works, but isn’t the property physically there?

Pleiades said in a post earlier:

“This is like a bee saying ‘a UV wave passes by and there are only humans around, does it really exist?’ Just because we can’t tell its there, doesn’t mean a) it isn’t, b) it isn’t useful to something else perhaps in some other way.”

Haha, I really liked this post. I’d also like to add, in addition to a) and b) above: c) That it isn’t affecting us directly. After all, we do not perceive UV rays but they give us cancer so they do affect us.

So what is reality then? In class we said that color is not an intrinsic quality of objects. I disagree. Because what is color? Color is directly related to the wavelengths of light adsorbed by an object, which is directly related to the energy of bonding systems within the compounds that make up the object. These things are fundamental to the object, regardless of whether or not they are perceived. If a tree falls in the forest, and no one is around to see it, its leaves still contain chlorophyll, and still adsorb green wavelengths of light, period. The fact that we call it “green” is merely so that a term can be used for the way the brain interprets the visual signal. It's for the sake of simplicity. I suppose one could, if one wanted to, say to their neighbor, "Oh my, I am perceiveing a wonderful 700 nm wavelength of light from your rose garden. However do you manage them so well?" If the argument is that the way our brain interprets the signal is not fundamental to the object, then that’s silly, because everything is interpreted by the brain, in which case nothing we see, hear, touch, taste, smell, whatever, is fundamental to the thing being sensed. Is that the point? If it is we may as well stop talking about this stuff, because OF COURSE, the only way that the world can be experienced by any creature is by way of a tool, and the brain (nervous system) is the tool we have to experience the natural world around us. “The brain is wider than the sky,” Emily Dickinson makes a cute point, but I just can’t see how that makes reality, i.e. the world outside the brain, any less “real.” Without brains walking/crawling/swimming about, the world would be exactly what our nervous systems know it is: a bunch of forces, elements, light waves, pressure changes, electrostatic forces, masses, and magnets that interact in an incredibly intricate manner. Our brain is a tool invented by billions of years of evolution because survival and reproduction/replication was aided by sensory systems that allowed organisms to react appropriately to inputs from these forces. Evolution, and the organisms for that matter, couldn’t give a hoot exactly HOW the signals are detected so long as they are detected.

So is color a construct of the brain?

Well, yes, if what you call “color” is the interpretation ONLY, and not the property of the object which is the signal being received and interpreted. But as I said before, this seems a bit silly because interpretation is exactly why brains evolved. The world didn’t evolve forces so that the brain would have something to interpret.

Just some thoughts.

Eighteenth-century empiricist philosopher George Berkeley made famous the line "to be is to be perceived."

This is to say that, in the vein of pure immaterialist and idealist philosophy, there are no mind-independent objects or material in our understanding of the world and reality. The only two things that we can conceive of are minds and ideas. Moreover, ideas exist only insofar as they are perceived by some mind. Berkeley goes further to inquire, "Are ideas under control of the will?" If an idea is not under control of the will, then this idea is one of sense. On the contrary, if an idea is in fact under control of the will, then this idea is one of imagination.

So, while Berkeley would certainly agree with the premise that if a tree falls in a forest and no one is there to witness such an occurrence, the tree does not make a sound, this account would not be sufficient. He would go so far as to say that not only does the tree not make a sound, but also that there is no tree to begin with.

This week’s lectures brought us right back to our discussion and frustration with defining and understanding reality. This week’s lectures revealed our human-centrism when we think about sensory systems. The example of a tree making no sound when in falls in the forest reveals this centrism. We have created and defined these sensory systems as those which are based around human experience and human understanding. We even discussed those animals which are sensitive to UV and infrared light in addition to the visual spectrum. Do these animals qualify as having vision because they can see the visual spectrum in addition to these other ranges of light? What would happen if there was an animal who could not see the visual spectrum but could see the infrared light spectrum alone? Would they still qualify as having “vision”? I would argue that the implications of saying that there is no sound if a tree falls implies that we have not truly understood sensational reality, but we have begun to understand sound/vision/our experience within reality.

We have agreed that it is the nervous system which is in control of our reality: it dictates what we can understand/make judgments about in the empirical world. This new information about color and sound further exemplifies the kind of sensors that our nervous systems have placed on the reality which may be out there. We experience a very selective reality, one which we can process, integrate and make judgments about. I stand by my posts from previous weeks in saying that I believe there is a very strong evolutionary reason for why this is the case. But regardless of the reasons why the nervous system works like it does, it is crucial to understand the ways in which the nervous system acts. Our discussion into vision and sound reveals the fact that there may be a part of reality that we cannot understand because our nervous system is not equipped to be able to comprehend and integrate signals from it. Since many different animals have different ways of understanding reality (specifically in the different ways of receiving and processing different kinds of light) it seems then that different parts of reality are revealed in unique ways to different animals. Simply put, your reality is dependent on your nervous system and how it operates.

Since there are differences in nervous systems across species and even among different animals in the same species and further differences between individuals, it is difficult to discuss “normalcy” and “disability.” Who sets the standard for what is normal and what is a deviation from normal? From our discussion of sound it seems that it is humans who set the standard and the bar for normalcy of senses. If you can see the visual spectrum, and you can hear between 20-20,000 Hz then you are “normal”. We push all the animals who have unique nervous systems to conform to our “normalcy” construction. Even worse, we push one another to fit into the bounds of being normal or not. What is disability? I don’t believe that having a nervous system which operates in a different way should be seen as a disability. That is true that you might not be able to see reds and yellows, but that isn’t necessarily strictly a disadvantage. Disability is completely relative to the “norm” you determine. We have based disability on nervous system and developmental problems for so long, yet I don’t think this is sufficient. A disability as seen by one person may be advantageous to another. Disability is a tricky issue, since we have already accepted there are different ways of seeing reality and it is difficult to assess which one is “better”. Nervous systems are different and they interpret signals differently and so realities are different for different people. Everyone is disabled then in some sense, but I doubt there is anyone who is actually the standard. When we say someone is disabled because they are colorblind we are making a judgment about what their reality should be like. Nervous systems are different, reality is relative, disability shouldn’t be seen as so black and white; end of story.

What we see is obviously not directly correlated to what we experience, otherwise not only would we would see exactly what is projected to our retina. From my understanding much of what we see is based on a sort of filling in process governed by probability and likeliness, probably a result of “short cuts” made in the brain in the evolutionary process. This is not just a visual phenomenon, where we can trick our minds to fill in our blind spot, it is also perceptual. That’s why when we see someone standing behind an object, a tree for instance, we don’t see a segmented person, we see a person standing behind a tree.

            In class we learned that our reality is an educated guess of the brain that is continually checked; though I have no reason to believe so, I think that visual input is not just processed in the visual cortex of the brain, but is sent to other systems and rechecked by other inputs that either confirm or contradict it and affect the resulting picture produced in our head. But what are the implications of this hypothesize, check and recheck system? Could your brain inhibit or create images in your field of vision or alter how you perceive existing images? How would your brain choose to prioritize or completely deny some objects and not others, if this is even possible?

            The only conclusion I can come up with is that, our highly complicated brains prefer the simplest and most probable route. This was seen in the experiments done in class on the blind spot; when a dot bisecting a line is placed in your blind spot, your mind fills the void by completing the line. This is because it is more likely that the two lines would be two halves of a single line segment rather then two lines that are perfectly aligned in space. But how far can we push this idea? Can our mind fill in more complicated occurrences, such as movement? After all we perceive an object as having continual motion even when part if its trajectory is hidden from us, and not as two independent motions of a single object. And does our mind simply omit input that contradicts the “best fit” image our mind creates from other inputs? Our brain can be continually creating new realities to incorporate all deviant input into the best fit image; that would be highly erratic and unorganized. What’s even more intriguing, assuming that either of these suggestions are possible, what if the ability of your mind to either create or inhibit images, perceptions or object was, for some reason or other, giving free range?