There's a longstanding belief that when someone loses one ability, another improves correspondingly. New research bears this out – in one scenario, at least – as it indicates that blind people remember spoken information better than their sighted counterparts.
The study was conducted by scientists from Johns Hopkins University and the University of California, Irvine. It involved 42 adult test subjects, 20 of whom were blind and 22 of whom were sighted but blindfolded.
In one exercise they listened to a list of spoken letters, followed by a delay, and then another list – which might or might not be identical to the first. They had to state which letters were different between the two lists, if any.
In another exercise, they tried to solve a mathematical equation while also listening to a list of spoken letters. The participants subsequently had to state if any of the supplied possible answers to the equation were correct, plus they had to recite back the list of letters.
It was found that for both tests, the blind individuals performed significantly better than those who were sighted.
"Blind people use their memory much more to remember things, while sighted people can rely on visual clues to recall information," said UC Irvine researcher Karen Arcos, lead author of the study. "We think blind people's advantages on the verbal tests stem from increased practice remembering information. The brain area responsible for vision in sighted people, the 'visual' cortex, is repurposed for other functions in blind people. Perhaps it enhances blind people's language processing."
Supporting this theory, it was observed that when the test subjects had to identify differences between two streams of sound effects – which were not sounds that could be easily associated with real-world objects, processes or other information – the blind and sighted people performed about the same.
"It's interesting that people who are blind only showed an advantage with verbal memory," said Johns Hopkins' Assoc. Prof. Marina Bedny, senior author of the study. "Blind people may use language like a mental tool to remember information."
A paper on the research was recently published in the journal Experimental Brain Research.
Source: Johns Hopkins University
