The secret to recalling 4,000 random numbers
A trick devised by a wandering Greek poet 2,500
years ago could explain why some people are astonishingly able to
recall almost everything while others can forget their spouse's
Neurologist Eleanor Maguire of University College
London recruited eight people who were among the top-placed in an
event called the World Memory Championships, along with two others
who had already been studied previously by scientists for their
prodigious feats of recall.
The annual championships in London are a ritual for
media amazement - they feature individuals capable of memorizing the
faces and names of 99 unknown persons, epic-length poems, 4,000
digits, 400 random words and speed-recalling in perfect order 52
shuffled playing cards.
The brains of these 10 were then compared against
those of 10 individuals of similar age who had average memories. The
scientists asked both sets of volunteers to do non-memory
intellectual tests and scanned their brains with functional magnetic
resonance imaging (fMRI).
The scans showed that brains with super-memories
were especially active in three regions - the medial parietal
cortex, retrosplenial cortex and the right posterior hippocampus.
But the secret to their total recall was not higher intelligence, a
better education or a different brain structure.
A close questioning of the memory champs found they
all used mnemonics - a mental technique attributed to a Greek
lyric poet, Simonides of Ceos in 477, who recalled all the sights
and landmarks along routes he had walked. Simonides' so-called
"mental walk" technique is more formally called
"method of loci".
Under this, an object or number is associated with
an image, which is set down as a salient point on a mental road.
This path is then retraced when it comes to recall time. For
instance, the volunteers had to memorize a series of snowflakes that
were each slightly different.
For most people, the images would quickly become a
forgettable blur. But those with mnemonic skills would look on a
specific part of each snowflake and associate it with another image,
such as people, animals or objects.
"Superior memory was not driven by exceptional
intellectual ability or structural brain differences," said Dr
Maguire, who headed a team whose work was reported on Sunday in the
monthly journal Nature Neuroscience. "Rather, we found that
superior memorizers used a spatial learning strategy, engaging brain
regions such as the hippocampus that are critical for memory and for
spatial memory in particular."
For some, mnemonics may seem like an "overly
complicated" skill that could have little relevance for
everyday life, she added. But the loci way of organizing information
could be highly useful to many people - and it may not be too hard
to master as it is simply a more efficient variation of normal
memory, she argued.
Previous studies have shown the technique has been
useful for elderly people suffering from memory loss and for people
with mental handicaps. Further research may confirm whether it could
help those with brain injury or brain disease. -- AFP