Early blindness frees brain-power for hearing

People born blind hear better than people who see. And according to a new study, it is the visual centre of the brain that gives them the edge.

The idea that blindness is linked with musical talent – think Ray Charles or Stevie Wonder – is borne out by systematic studies. People blind from an early age really do out-hear both sighted and late-blind people. They learn to recognise new voices more quickly and can discern changes in pitch that are undetectable to sighted people.Franco Lepore at the University of Montreal in Canada and his team wanted to see if early-blind people were borrowing capacity from their visual cortex to help locate sounds. They asked seven sighted and 12 early-blind people to identify where sounds were coming from, using one or both ears. They then did a similar experiment inside a PET scanner.The early-blind people were better at pinpointing sounds – and the better they were at this, especially with one ear, the more the “visual” areas of the brain were activated. This shows, says Lepore, that the brain is deliberately recruiting these areas to help, not just accidentally activating them because they are lying idle.(Source: News Scientist: January 2005.)