What effect does studying vision have of the perception of reality? I remember you saying in class a while back that the creation of the picture that each of us has of reality is not a passive process, but is an active one. That struck me. Everything that we encounter and that we see (well maybe not everything) is processed and incorporated into our reality. I don't think that the brain filling in the blind spot on the retina makes a large difference is the our senses of reality, but I think that it makes an interesting example of how the brain can "fill in" information that isn't really there. Based on past experiences or mood, etc, the brain can take an ambiguous situation and fill in the information and details it and make that reality. This is what a lot of psychological tests bank on (the TAT for example studies people's personalities by looking at how they interpret ambiguous pictures.)
What is reality anyway? It seems that reality is the way that we perceive the things in our environment, and part of that has to do with our experiences and the pathways we have built in our brains for processing, and part of it with human biology. There are many things in our environment,(sonar, infared, radio waves,) that we are just not able to consciously perceive, while other species may be able to. So reality is specific to a species. I would guess that this is somehow advantageous, and that each species develops a way to perceive sensory input that it needs. But not only is it species specific, but reality is different for individuals. Granted, as a race, humans in a given culture have generally the same sense of reality, but differ on thousands, millions, of points. Look at the way that someone who disagrees with Newt Gingrich will portray his image and what he stands for, or the way that witnesses to the same crime will report a different story. What they are saying is real for each of them, but it is different because of the way that they perceived the talk or the situation. So in a way, it seems like what you actually see is a pretty small part of what it means to have a sense of reality. The brain has a lot of influence on how that input is processed and recorded. Hallucinations are another example. When people see things that aren't really there. Hearing voices is another example of a neurological abnormality interferring with reality, but we're talking about vision right now. When someone sees their house on fire or suddenly finds themselves reliving a scene that they saw during a war, their brain is creating these images and making them seem real to the person. It's scary.
Good points, but also worth dissecting them a bit more. Yes, of course, the blindspot is one example of a much larger array of phenomena of organisms and people "seeing things differently", and its important to understand that they do. It also helps to keep in mind that the differences can occur at different levels of organization, and have different explanations. The blindspot is a very "peripheral" (close to the edge of the nervous system") effect, and probably largely genetic. How one sees Gingrich is a much more central effect, and much more a function of experiences/education. Some differences are more fixed, others more labile, and so forth. And, as we'll see in a bit, "consciousness" adds an additional layer of complexity. One doesn't have to be "conscious" of seeing things to see them in a particular way, different from how other organisms/people see them. Scarey? Yes, in one sense. But exhilirating in another. No organism (or person) can see everything. But if everyone sees a little bit differently, and we share what we individually see, then ....? Maybe there's a good reason for science, and talking about things, and so forth? Maybe "reality" is what we collectively work out, together, from all our experiences? Would that be so bad? PG