Repeated exposure key to remembering faces

Last Updated: Sep 10, 2010, 11:34 AM IST

London: Faces and words that reactivate neural patterns in the same region of the brain over and over again are more likely to be remembered, revealed a study.

People find it easier to recall things if material is presented repeatedly at well-spaced intervals rather than all at once.

For example, you`re more likely to remember a face that you`ve seen on multiple occasions over a few days than one that you`ve seen once in one long period.

One reason that a face linked to many different contexts — such as school, work and home — is easier to recognize than one that is associated with just one setting, such as a party, could be that there are multiple ways to access the memory.

Psychologists proposed this idea, called the encoding variability hypothesis, about 40 years ago, reports Nature.

Each different context or setting activates a distinct set of brain regions; the hypothesis suggests that it is these differing neural responses that improve the memory.

But neuroimaging research led by Russell Poldrack, a cognitive neuroscientist at the University of Texas, Austin, now suggests that the opposite is true — items are better remembered when they activate the same neural patterns with each exposure.

In addition, attention-grabbing words or faces may elicit more reproducible patterns of activation when they are presented multiple times than do less striking items, said Rik Henson, a cognitive neuroscientist at the MRC Cognition and Brain Sciences Unit in Cambridge, UK.

This effect could explain the results without refuting the encoding variability hypothesis, he added.

The study has been published in Science.