Hidden View

In a stunning phenomenon called ‘blindsight’, people who are blind in one eye can respond to visual stimuli they can’t consciously see at all. They might, for example, be able to grab an object to their side, only in the line of ‘sight’ of their blind eye. To investigate, researchers scanned the brains of healthy volunteers (left) and a patient with damage to one side of the brain (right). They found that the intact side compensates for, and communicates with, the injured. When the patient responded to stimuli they could actually see to one side, the corresponding half of the brain was active. However, when they responded to ‘hidden’ stimuli, both sides of the brain were involved, as were the fibres connecting them (the corpus callosum, blue and larger in the injured brain). Understanding these inbuilt compensation and repair mechanisms could help us encourage recovery after brain injury.

Written by Anthony Lewis

Anthony Lewis

Writer

Ant was the web editor in the early days of BPoD, and has since worked with the UK’s top science organisations as a writer and multimedia producer. He now splits his time between freelance work and managing multimedia at The Lancet.

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• Image from work by Alessia Celeghin and colleagues
• Department of Psychology, University of Torino, Torino, Italy and Department of Medical and Clinical Psychology, Tilburg University, The Netherlands
• Image copyright held by the original authors; image reproduction permitted by PNAS
• Published in PNAS, November 2017