A Blind Man Learns To See

Two years after the surgery, MM’s simple form, color and motion processing were essentially normal, but his three-dimensional perception and object and face recognition were severely impaired. For example, he had no difficulty recognizing simple shapes such as a square or circle, but he could only identify 25% of common objects that were presented to him, and he was able to tell whether an unfamiliar face was male or female only 70% of the time. His motion perception was perhaps the most well-preserved visual faculty, and functional imaging showed that a motion processing area of his brain was activated normally.

Like other sight-recovery cases, MM was not fully comfortable with his new sight after the operation. He was an expert skier as a blind person, but immediately after surgery he would close his eyes while skiing, as the visual information frightened him. Since his operation, he has learned to interpret visual images more effectively, but says that he is “still guessing” at what he sees in many cases.

Author contact:

Ione Fine
University of California at San Diego
La Jolla, CA
USA
Tel: +1 858 822 0606
E-mail: fine@salk.edu

Additional contact for comment on paper:

Richard Gregory
University of Bristol, UK
Tel: +44 117 928 8461
E-mail: richard.gregory@bristol.ac.uk

Also available online.

(C) Nature Neuroscience press release.

Message posted by: Trevor M. D'Souza