Scientists say it may be
possible to predict how well we will remember something
before the event has even taken place.
By analysing scans, they discovered the
brain must get into the 'right frame of mind' to store
new information.
For top performance, the brain must mobilise
its resources, not only at the moment we get new information,
but also in the seconds before.
The University College London research
features in Nature Neuroscience.
Previously it was thought that brain activity
after an event, not before the event, was key.
Lead researcher Dr Leun Otten said: "It
sounds a bit like clairvoyance in the sense that we're
able to predict whether someone will remember a word before
they even see it.
"Scientists knew that brain activity
changes as you store things into memory but now we have
found brain activity that tells how well your memory will
work in advance."
Activity patterns
The UCL team conducted two experiments
in which volunteers were given a cue moments before being
shown an item.
The cues either gave clues as to how
the item should be interpreted, what form it would take,
or, in the case of words, how the letters were arranged.
The volunteers were not told to try to
memorise the items, and the cues were specifically designed
not to nudge the memory.
During the tests, electrical activity
in the volunteers' brains was monitored using an EEG (electroencephalogram)
scanner.
Tests showed that the brain's electrical
activity differed after the cue and before the word was
presented.
This was linked to whether the subject
would remember or forget the word in a later unexpected
memory test.
'Staying alert'
If the electrical activity maintained
a high level over frontal parts of the scalp just before
an item was shown, then it was likely that the subject
would remember it up to 50 minutes later - and after doing
a series of other word tests.
On the other hand, if the voltage was
lower, the subjects were less likely to remember the word.
Dr Otten said: "It would be nice to know
what brain regions are involved in this preparatory activity,
and whether it can be used to help people who have difficulties
remembering things.
"Unfortunately we aren't at that stage
yet. What we do know though is that it might have something
to do with trying to get into the right frame of mind
to make a decision about a word's meaning.
"Staying alert between the cue and the
word also appears to help. We are currently trying to
find out more about this kind of brain activity and how
it helps long-term memory."
Professor Ian Robertson, of Trinity College
Dublin, told the BBC News website the findings made sense.
He said: "We perceive things faster that
we are primed to expect, and this is because the very
basic sensory and perceptual processes are tuned by the
expectation.
"It makes sense that this happens in
memory - that the brain can be more or less prepared or
primed to encode a memory.
