When I first read about this research I was afraid to be confronted with a new kind of Brain Gym, but this is actual science. Than I started reading the research and again I’m getting a bit nervous because of the left-right hemispheres, but do read on. The 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 (so nothing about creativity there).

ABC interviewed one of the researchers:

“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 atMontclair 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

But… before you start clenching your fists, a bit of reality check:

This pattern also improved memory compared to not clenching at all, although the difference was not statistically significant, possibly due to small sample sizes. And also in the study, 51 solely right-handed subjects were asked to squeeze a small rubber ball as hard as possible for two sets of 45 seconds, then asked to remember or recall as many words as possible from a list of 36. So no news about the lefties!

Abstract of the research published in PlosOne (thus freely accessible)

Unilateral hand clenching increases neuronal activity in the frontal lobe of the contralateral hemisphere. Such hand clenching is also associated with increased experiencing of a given hemisphere’s “mode of processing.” Together, these findings suggest that unilateral hand clenching can be used to test hypotheses concerning the specializations of the cerebral hemispheres during memory encoding and retrieval. We investigated this possibility by testing effects of unilateral hand clenching on episodic memory. The hemispheric Encoding/Retrieval Asymmetry (HERA) model proposes left prefrontal regions are associated with encoding, and right prefrontal regions with retrieval, of episodic memories. It was hypothesized that right hand clenching (left hemisphere activation) pre-encoding, and left hand clenching (right hemisphere activation) pre-recall, would result in superior memory. Results supported the HERA model. Also supported was that simple unilateral hand clenching can be used as a means by which the functional specializations of the cerebral hemispheres can be investigated in intact humans.