From ABC News in Science, 25 April 2013:
Studying for an exam? Clench your right hand. Trying to remember a phone number? Clench your left.
That’s the suggestion of a new study into the effects of fist clenching on memory.
US researchers have examined the effect of single fist clenching on memory, based on the theory that the physical action in one hand increases activity in the opposite side of the brain.
Their study, the first to test the role of different brain hemispheres in memory encoding and retrieval, is reported today in the journal PLoS One .
“We’re cross-wired for body parts, so if you clench your right hand you’re really causing a change in the activity of the left side of your brain and if you clench your left hand you’re really causing activity to change in the right side of your brain,” says lead author Associate Professor Ruth Propper, director of the Cerebral Lateralization Laboratory at Montclair State University.
“It turns out that not only do motor areas of the brain become active, which you would expect if you’re moving a body part, but so do some more frontal areas of the brain also become more active when you start clenching your hand like this,” says Propper.
The study showed that clenching the right fist to activate the left side of the brain just prior to absorbing information, and clenching the left fist to activate the right side of the brain just prior to recalling it, resulted in superior recall compared to the opposite or different clenching patterns.
This pattern also improved memory compared to not clenching at all, although the difference was not statistically significant, possibly due to small sample sizes, the authors suggest. Read more.