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.
Earlier 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.
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
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".
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.