Congenitally blind people are whizzes at memory skills, according to a study published in the journal Behavioural Brain Research.
Michael Proulx from the Department of Psychology, the University of Bath, who investigates fundamental issues in cognition through the study of multiple sensory modalities, and his colleagues found that individuals with no visual experience had the most superior memory skills.
AdvertisementEarlier research on remembering word lists showed that most people falsely remember words that are connected to the words they are actually told, but weren't included in the list. This is called the false memory. For example, hearing the words 'chimney', 'cigar' and 'fire' could trigger a false recollection of the word 'smoke'.
Studies had also reported that congenitally blind people possess superior verb-generation skills.
So, in this study, researchers, Achille Pasqualotto, Jade Lam, and Michael Proulx tested the impact of blindness on capacity and the fidelity of semantic memory by using a false memory paradigm.
Semantic memory is a part of long term memory that deals with structured record of facts and concepts not related to personal experiences and involves conscious recollection of factual information whereas episodic memory stores specific personal experiences and events.
The researchers conducted memory tests on three groups of people - congenitally blind, those with late onset blindness, and those with sight. Each participant listened to a series of word lists and was then asked to recall what they had heard.
"We found that congenitally blind participants have enhanced memory performance for recalling the presented words and reduced false memories for the lure. The dissociation of memory capacity and fidelity provides further evidence for enhanced verbal ability in the blind, supported by their broader structural and functional brain reorganization," reported the researchers.
Sighted and those with late onset blindness remembered fewer words that were said, and more that were not.
"We found that congenitally blind participants reported significantly more correct words than both late onset blind and sighted people," said Dr Achille Pasqualotto, at Queen Mary University of London, and the lead investigator of this study. "Most of the congenitally blind participants avoided unrelated words, therefore congenitally blind participants can store more items and with a higher fidelity".
Findings of an earlier study published in the journal Current Biology, revealed that blind volunteers recalled 20 to 35 percent more words than sighted ones did, indicating a better memory overall, and they could remember almost twice as many more words in sequences according to the right order.
"Normally 20 to 30 percent of the brain is basically devoted to vision. With the congenitally blind, you have this brain area, the visual cortex, not getting its natural input," explained the lead researcher of the study, neurobiologist Ehud Zohary of Hebrew University in Jerusalem. "We had shown that congenitally blind people appeared to be using the visual cortex for other needs, and now we may be seeing part of how this area is getting used for other functions, to maybe be more involved in memory and language processes".
"There is an old Hebrew proverb that believes the blind were the most trustworthy sources for quotations and that certainly seems true in this case," said Proulx and concluded, "It will be interesting to see whether congenitally blind individuals would also be better witnesses in forensic studies".
Reference: Pasqualotto, A., Lam, J. S. Y. and Proulx, M. J., 2013. Forthcoming. Congenital blindness improves semantic and episodic memory. Behavioural Brain Research, 244, pp. 162-165.