Читать книгу The Form Within - Karl H Pribram - Страница 47

James and Eleanor Gibson of Cornell University, using purely behavioral techniques, had also reached the conclusion that higher-order distinctions are learned. The Gibsons reported their results in a seminal publication in which they showed that perceptual learning is due to progressive differentiation of stimulus attributes, not by forming associations among them.

Taking Matte Blanco’s definition that our conscious experience is based on making distinctions, as described in the opening paragraphs of this chapter, this line of research indicates how our brain processes, through learning, make possible progressively greater reaches of conscious experience.

The processes by which such distinctions are achieved were addressed at another meeting of the Society for Neuroscience—this one in Boston in the 1980s. Once again, David Hubel gave a splendid talk on how brain processes can entail progressively greater distinctions among colors. He noted that, as we go from receptor to visual cortex and beyond, a change occurs in the coordinates within which the colors are processed: that processing changes from three colors at the receptor to three opponent pairs of colors at the thalamus and then to six double-opponent pairs at the primary sensory cortex. Still higher levels of processing “look at the coordinates from an inside vantage” to make possible the experiencing of myriads of colors. A change in coordinates is a transformation, a change in the code by which the form is processed.

Transformations are the coin of making ever-greater distinctions, refinements in our conscious experience. After his presentation in Boston, I spoke with David Hubel and said that what he had just done for color was exactly what I was interested in doing for form. David said he didn’t think it would work when it came to form. But of course it did. The prodigious accomplishments of the 1970s and 80s form the legacy of how visual angles at different orientations can become developed into a Pythagorean approach to visual pattern vision. (Hubel and I have never had the opportunity to discuss the issue further.)