Friday, March 27, 2009

Screens -The Shrines of Itsukushima and Wakanoura -- Twenty Percent

Art and studying art fascinate me. A close rival is brain research. How does that gray matter up there work? How is that we can think and smell and hear and see? The New Yorker recently published an article entitled The Itch by writer and surgeon Atul Gawande. In it he talks about how we see.
We can tell if something is liquid or solid, heavy or light, dead or alive. But the information we work from is poor -- a distorted, two-dimensional transmission with entire spots missing. So the mind fills in most of the picture. You can get a sense of this from brain-anatomy studies. If visual sensations were primarily received rather than constructed by the brain, you'd expect that most of the fibres going to the brain's primary visual cortex would come from the retina. Instead, scientists have found that only twenty per cent do; eighty per cent come downward from regions of the brain governing functions like memory. Richard Gregory, a prominent British neuropsychologist, estimates that visual perception is more than ninety per cent memory and less than ten per cent sensory nerve signals.

So if I understand the research correctly we all are seeing objects differently because only ten to twenty percent of the input to the visual cortex comes from the retina. What I see or what Amy sees may be boats and people but what others see may be the colors and shapes like in the image above of the right three panels of the screens. Then they add in other elements from their memories. Sometimes when I first see a complicated image like the screens in the post yesterday (also the image of the week for Week 13), I see blocks of colors and shapes. Even after I realize that there is detail within the image my main impression is the colors and shapes.

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