Afterimages and Token Identity Theory - Essay Example

YOUR FULL Word count 306 YOUR Afterimages and Token Identity Theory I have just stared at a bright neon light bulb shaped like a cow for exactly one minute. When I close my eyes, I can see an afterimage of the cow, but it is changing colors and the shape is shifting somewhat. After a while, the image disappears entirely. If someone was examining my brain or visual nervous system, they would not be able to detect this afterimage as a shape-shifting, color-changing cow. This calls into question whether or not the afterimage exists at all; and if it does, is it physical with a real color and real shape or is the image I see not physical at all. Three possible positions. To answer this question, there seems to be three logical positions for explaining what I see. First, there is the assertion that the afterimage doesn't exist at all. This position makes a certain amount of sense to me, because I understand that seeing requires the use of my eyes and that my eyes respond to light. If my eyes are closed, there is no light hitting them and I shouldn't be able see anything. This view is problematic for me, however, because I can still see the image before me. It may be changing colors and the shape may be shifting, but I can perceive it very clearly. If the image did not exist at all, then I wouldn't be able to see it. Therefore, since I can see it, it has to exist somewhere. The second position is that the afterimage exists, but it isn't physical. I can accept this idea more easily than the first because it allows me to believe in the reality of what I see without having to prove that it exists in a physical sense. This view is also problematic, however, because it challenges my rationality; I am seeing the image when I shouldn't be able to. I can describe the changes in color and shape. Even though the image eventually goes away, I know that I continued to see it after I closed my eyes. I don't have a good explanation for why I can see it, however, because I know that it isn't physically possible for me to see it. To adopt this position, I have to explain why I can see something that is no longer there; and that isn't very logical. The third and final explanation for the afterimage is that it exists and that it is physical. On its face, this position gives me the most options for believing in the image that I see because I can attribute its reality to a physical process. Even though I may not be able to explain exactly what is happening, this position allows me to assert that the image is real and that there is a rational physical or biological reason for it. Unfortunately, this position has its own difficulty with my understanding of vision. Even though I can describe the afterimage in terms of its shapes and colors, to assert that there is a physical reason violates what I know about the biological process of vision. I see with my eyes because light stimulates the nerves and those nerves transmit the image to my brain. If my eyes are closed, then I shouldn't be able to see anything because there is no light coming into my brain. Once I close my eyes, the neon cow cannot be truly seen because there is no more light being processed by my visual nerves. Determining the answer to this question is difficult because I have to balance what my eyes are seeing with what I know about vision. As Seager states in his discussion of token identity theory, "[t]he essential idea is that mental states are ascribed through the interpretation of behavior under the constraint of rationality" (54). My mental state of seeing the colored cow and interpreting its behavior is constrained by my own rational mind. My position. I will argue for position two, the view that the afterimage exists, but it is not physical. Even though this position has problems, I think this is the best explanation for the afterimage. First, the image exists for me. I see it, so that excludes position one, but there is no real physical reason to do so; which excludes position three. As I try to explain why I can see it even though it is not physical, I have to understand the difference between sensation and perception. "Perception is the awareness of things in the world. Sensation, on the other hand, is the awareness of changes in one's own bodily state or condition" (Thompson, 247). While the cow may not be able to be perceived in a physical sense, it can be explained as a sensation where I am aware of my body producing the afterimage. This position is further supported by Thompson when he states, "[u]nlike visual perception, then, the experience of having an afterimage is one of feeling one's bodily condition in vision change along certain qualitative dimensions; and the experiential character of these felt changes is relatively unstable and impermanent" (248). This explanation of afterimages explains why the colors and shape change; the afterimage is a sensation. It can be real, without being physical or perceived. Second, I know that my mind has the ability to create these sensations in order to make sense of perceptions and their aftermath. As [NAME OF AUTHOR OF TEXBOOK] says in the discussion on seeing spots before the eyes, "[i]f we say they aren't real, doesn't that mean only that they aren't a part of the public physical world...they are real in the sense that they really do occur in your experience." (AUTHOR 173) It is here that I find the best support for my assertion that the afterimage is real, but is not physical. It is real for me. It exists because it is a part of my experience, and without a definable, physical condition being present, my mind is continuing to produce the sensation of the cow I saw as it tries to organize the information by temporarily giving the sensation of an image where none technically exists through stimulation of my visual nerves. The strongest objection to this concept says that the image is not real, because my eyes are closed and there is no physical reason for me to continue to see it. This objection does not succeed, however, because it relies upon perception, through a physical stimulation only, and does not allow for visual sensation subsequent to seeing the light. With the idea that something can be real within my experience without being a part of the public and physical world, there is an adequate explanation for why the image is real to me but may not be physical and observable to someone who was looking into my brain or monitoring my physical visual nerves. The afterimage exists, because I see it and experience it; but it isn't physical. Its odd behavior of changing colors and altering its shape is a sensation provided by my mind as it tries to process the residue of color and shape, organize it into meaningful information, and making some sort of sense out of all the elements. Ultimately, the afterimage disappears because the brain finishes its process. This provides an acceptable explanation of my mental state as I rationally try to interpret my brain's behavior. Works Cited AUTHOR. "Mind and Body." NAME OF TEXTBOOK. CITY: PUBLISHER, DATE Seager, William. Metaphysics of Consciousness. New York: Routledge, 1991. Thompson, Evan. Color Vision: A Study in Cognitive Science and the Philosophy of Perception. New York: Routledge, 1995. Read More