From today's New York Times:
Forgetting May Be Part of the Process of Remembering
By BENEDICT CAREY
June 5, 2007
Whether drawing a mental blank on a new A.T.M. password, a favorite recipe or an old boyfriend, people have ample opportunity every day to curse their own forgetfulness. But forgetting is also a blessing, and researchers reported on Sunday that the ability to block certain memories reduces the demands on the brain when it is trying to recall something important.
The study, appearing in the journal Nature Neuroscience, is the first to record visual images of people’s brains as they suppress distracting memories. The more efficiently that study participants were tuning out irrelevant words during a word-memorization test, the sharper the drop in activity in areas of their brains involved in recollection. Accurate remembering became easier, in terms of the energy required.
Blocking out a distracting memory is something like ignoring an old (and perhaps distracting) acquaintance, experts say: it makes it that much harder to reconnect the next time around. But recent studies suggest that the brain plays favorites with memories in exactly this way, snubbing some to better capture others. A lightning memory, in short, is not so much a matter of capacity as it is of ruthless pruning — and the new study catches the trace of this process at it happens.
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