Title: "What does the brain do when the eyes can't see:

Cortical reorganization in the congenitally blind."

Ehud Zohary

Department of Neurobiology

Alexander Silverman Institute

The Hebrew University of Jerusalem

Abstract:

The visual cortex may be more modifiable than previously considered. Using fMRI in ten congenitally blind participants, we report robust occipital activation during a verbal-memory task (in the absence of any sensory input), as well as during verb-generation and Braille reading. We also found evidence for reorganization and specialization of the occipital cortex, along the anterior-posterior axis. While anterior regions showed preference for Braille, posterior regions (including V1) demonstrated preference for verbal-memory and verb-generation (which both require memory of verbal material). No such occipital activation was found in sighted. This difference between the groups was mirrored by superior performance of the blind in various verbal-memory tasks. Moreover, the magnitude of V1 activation during the verbal-memory condition was highly correlated with the blind individual's abilities in a variety of verbal-memory tests, suggesting that the additional occipital activation may have a functional role.