Artists, the original neuroscientists

DIVYA GANDHI

Could Picasso, Matisse or Andy Warhol, with their magnificently inexact representations of the real world possibly offer anything to the empiricism of neuroscience?

Neuroscientist Patrick Cavanagh, director of the Vision Sciences Laboratory, Department of Psychology, Harvard University believes that these very distortions, artistic “short-cuts” and deliberate “mistakes” reveal the artists’ intuitive mastery over key principles of visual cognition. And it is this skill that enables them to so effectively portray the impressions they intend to.

Vision takes up a third of the cerebral cortex, and each of the 30 billion neurons that make up the visual system analyse a small portion of the world for colour, movement and orientation. So powerful is this visual computational device that the brain often needs just a ‘hint’ at forms to construct images, which it retrieves largely from ‘stored information,’ Prof Cavanagh said. The visual brain guesses, makes assumptions and constructs a story. “Artists must deal with these processes of inference,” not so much with real physics.

Artists reveal that our visual brain uses a “reduced physics” to see the real world, often relying on memory and inference rather than true physics, to quickly and efficiently form perceptions, said Prof Cavanagh at a lecture at the Indian Institute of Science (IISc) on ‘The artist as neuroscientist’ earlier this week. And in doing so they have, beginning with cave painters, created a record of “40,000 years of experiments in vision,” he said. “They are the original neuroscientists.”

Writing in a paper for Nature in 2005, he had said on the same subject “Impressionism and Cubism in particular rely on this memory-based reconstruction to complete scenes from partial representation.” Artists, he writes, use “an alternative physics” because certain deviations from true physics “do not matter to the viewer". The artist “can take shortcuts presenting cues more economically.”

The economy of line drawings, or the high-contrast format of pop art are spectacular examples of artists discovering principals and shortcuts that the visual brain uses to create an image, he told his audience at IISc’s faculty hall.

Artists also appear to have known for centuries another curious fact about our visual brain that scientific experiments have only recently established: we have little understanding of how reflections, mirrors and shadows work.

“In a painting almost any reflection will do… The pattern only needs to match the average properties of natural scenes.” And so the most impossible reflections are entirely accepted by viewers.

These undetected errors, he said, “are the ones that tell us which rules of physics actually count for visual perception. As artists find the rules they can break without penalty, they act as research neuroscientists and we have to only look to their paintings to uncover and appreciate their discoveries.”

ProfCavanagh's public lecture was part of The 3rd Bangalore Cognition Workshop.

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