Let us now ask, is it really the case that our experience represents the world in sharp focus, uniform detail, and brilliant color, from the center out to the periphery of the visual field, as Mach's picture would have it? ...I don't think this argument works. (The Machian picture may be wrong, but this argument as it stands does not support that conclusion.) Remember that the Machian picture is supposed to be about one's perceptual experience, not about, say, the relationship between the world and one's perceptual experience. The view is that "our experience represents the world in sharp focus, uniform detail, and brilliant color, from the center out to the periphery of the visual field". Now, it is perfectly possible for us to have this kind of experience by way of some mental representation without the putative representation of that experience being created using input from the periphery. So, the reason you cannot tell the color of the paper when it is waved in the periphery is that you are not using color input (although definitely motion input) from the paper to create the putative mental representation of the periphery of you visual field. You are using other mechanisms to fill this out. Which is, of course, just the kind of thing one typically postulates when one tries to explain the blindspot phenomena.
It's pretty easy to demonstrate that this snapshot conception is wrong-headed. Fix your gaze on a point straight ahead. Have a friend wave a brightly colored piece of paper off to the side. You'll immediately notice that something is moving in the periphery of your visual field, but you won't be able to tell what color it is. As your friend to move the paper closer to the center of the visual field. You won't be sure what color the paper is until it has been moved to within twenty to thirty degrees from the center. This proves that we don't experience the periphery of our visual field in anything like the clarity, detail, or focus with which we can take in what we are directly looking at. (p. 49).
Monday, April 26, 2010
Noë on Mach's Picture
In Action in Perception, Noe writes,