Opening the Mind’s Eye - Learning to See

author: Pawan Sinha, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, MIT
published: Aug. 12, 2010,   recorded: June 2009,   views: 983
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It’s rare to find research that simultaneously advances basic science and brings good into people’s lives, but Pawan Sinha’s Project Prakash does precisely that. An investigator of human visual processing, Sinha is interested in how these brain mechanisms develop. For his work, Sinha realized the ideal subjects would be individuals who developed sight after blindness. Since he could not ethically create such an experimental population, he had to “rely on natural experiments” -- children born blind, but who recovered their vision.

Sinha found these subjects in his native India, which has the world’s highest number of blind children -- more than one million. They are victims of Vitamin A deficiency, congenital cataracts, and absent or atrocious medical care. But salient to Sinha’s research, many of these blind children could be treated. He glimpsed a humanitarian and scientific opportunity, and Project Prakash (Sanskrit for light) was born.

Starting a few years ago, Sinha and his team began screening blind children in a few villages to identify cases of treatable blindness, and remedy their disorders. More recently, he’s gained support from hospitals and schools for the blind, reaching many more children. He began to establish a test population. Research on this unique group has yielded many original insights into the development of vision, and shaken some major scientific dogmas. Sinha found that after years without visual stimuli, the brains of these children could process new information flooding in -- challenging the notion of early critical periods in brain development. He discovered that patients who once learned about objects simply via touch could, once they gained sight, identify the same objects simply by looking at them.

Sinha has also delved into the mechanisms of visual integration -- how our brains make sense of visual cues containing diverse colors, illumination, and patterns. He’s learned that newly sighted patients have difficulty parsing overlapping images (such as triangles, squares, circles), but moving these images around magically sparks recognition. Research results are consistent across all ages, and show that early stages of sight acquisition involve seeing the world in a fragmented way, compromising recognition, and that motion cues are critical for putting pictures together meaningfully, serving “a critical bootstrapping function for visual learning.”

The kinds of integrative difficulties experienced by Project Prakesh children bring to mind similar difficulties in autistic children, for whom motion processing also seems to be deficient, and Sinha is now seeking a possible “causal chain in autism” that leads to the disorder’s devastating social impairments -- a research path that might someday yield new therapies.

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