Every once in awhile a book appears by someone outside of the field of vision that captures components – or even the essence of vision, in a very beautiful way. By outside of the field I mean an individual who is not an optometrist or vision scientist in a conventional sense, but someone like Nicholas Mirzoeff, Professor of Media, Culture and Communication at NYU. He is one of the founders of the academic discipline of visual culture in books, and Deputy Director of the International Association for Visual Culture.
I chanced upon Professor Mirzoeff ‘s new book while browsing the Reviewers Copies section in B & N, but it’s a bargain at any price, for this section alone (pp. 81-5). The words and images are all his, save for the Boogie-Woogie graphic and YouTube. It runs a bit long, so I’ve parsed it into two segments.
“In short, seeing is a very complex and interactive process. It does not, in fact, happen at a single place in the brain, as the first ‘lighting up’ images had suggested, but all over it in a series of rapid back-and-forth exchanges. Further, this interactivity between the visual zones of the brain and their associated areas happens at a series of ten to fourteen hierarchical levels. That is to say, seeing is not a definitive judgment, as we had once assumed, but a process of mental analysis that goes backward and forward between different areas of the brain. It takes a brain to see, not just a pair of eyes.
Felleman and Van Essen created a diagram of vision in the era of digital computing. In this mapping, the neural pathways for each sense are distinct but are processed in parallel, as in a computer. Their understanding of vision shows it as a set of feedback loops. Their map looks quite unlike any earlier model of seeing.
The one point of overlap with Descartes’s earlier Drawing is that the retina is still included. It’s right at the bottom, labelled RGC. What we can vision happens in the set of feedback and parallel processing that takes place between this point and the hippocampus (HC) at the top. Clearly, vision is not just a case of light entering the eyes and being judged, as it was for Descartes. It is a back-and-forth shuffle with twists and turns, creating a vibrant sense of rhythm in the image.