Want to remember something? Clench your fists!
Giving a speech and need to remember what to say? Just clench your right fist while rehearsing. Then, when it's time to give the speech, clench your left fist, and voila, you’ll recall what you rehearsed! That's what a new study found, which was published April 24 online at PLOS ONE.
The study was authored by Ruth Propper, an associate professor and director of the cerebral lateralization laboratory at Montclair State University, to learn more about how body movements influence brain activity, a subject that has intrigued Propper for a long time. Although researchers understand how the brain influences the body (e.g. when the brain senses pain if you put your hand on a hot stove, causing you to yank it away), not as much is understood about how the body influences the brain.
Previous studies have suggested that clenching fists can stir certain emotions. For example, clenching your right fist boosts activity in the left side of your brain, evoking emotions associated with positive anticipation or well-being. However, when clenching your left fist, your right side of the brain is more activated, evoking less positive emotions, such as fear or anxiety. While these less positive emotions may not seem very helpful, they can actually save your life in a dangerous “fight or flight” situation, not to mention save you from less perilous situations that require a rapid response.
Given prior research that has shown fist clenching's affect on the brain, Propper theorized that it could influence the brain in other ways as well.
To test her theory, she therefore launched her study to find out more about the influence of fist clenching on memory and recall. In so doing, Propper asked 51 right-handed participants to memorize 72 words, randomly assigning each participant to one of five fist-clenching groups or to a control group that did no fist-clenching at all. The reason Propper tested only right-handed participants is that left-handed people – in general – tend to have stronger memories; thus, including them in the study would give them an unfair advantage.
As part of the study, the right-handed participants were instructed to squeeze a pink rubber ball as hard as possible for two sets of 45 seconds, with an intervening 15 second break. The no clenching control group held the same ball gently in both hands with no squeezing.
According to Propper’s findings, the perfect combination for better memory and recall occurs when a subject clenches his right hand while memorizing and balls up his left hand while trying to recall the memory.
“It is interesting to compare to not clenching at all. It’s almost 15 percent better [to clench right then left] than sitting there,” she says.
Although some may say a 15 percent increase is not that statistically significant, Propper points out that 15 percent can make a difference between an A and a C on test.
In the meantime, Propper acknowledges that more research is needed to get a better grip on how the body influences activity in the brain, but she recommends that people try clenching their fists to see if it helps improve memory.
“I would say that it would be worth trying,” Propper says. Using the example of parking your car in the parking lot, she added: “As you park, you can clench your right hand, and when you are trying to find it, clench your left hand.”
If you frequently forget where you parked your car in a parking lot, clenching your fists may prove to be an easy way to get a grip on your memory problem.
SOURCE: Propper RE, McGraw SE, Brunyé TT, Weiss M (2013) Getting a Grip on Memory: Unilateral Hand Clenching Alters Episodic Recall. PLoS ONE 8(4): e62474. doi:10.1371/journal.pone.0062474. PLoS One.