Turns out, little zaps to the brain can help you retain memories.
Relatedly, while researching the way we forget everything, researchers accidentally discovered a way to stimulate better memory among participants of a study recently published in the journal PLOS Biology.
But we're still years away from transforming these findings into actionable, marketable research.
Soft 'zaps' to the brain tend to enhance memory performance
The experiment was initially conducted in 2012, if you can believe it. At the time, it was designed to explore the role the left dorsolateral prefrontal cortex (DLPFC) plays in voluntary forgetting. The experiment successfully showed how intentional forgetting was actively managed by the DLPFC, but the data had a bonus feature hidden away. And a recent follow-up analysis has shown that stimulating this part of the brain with a specific frequency of magnetic stimulation while we learn new material actually helps us to retain the new knowledge later on. "We were quite surprised when we saw these effects in the first study, which was designed to investigate a different question," said Simon Hanslmayr, a cognitive neuroscientist at the University of Glasgow.
To verify the results, the researchers carried out a second experiment involving 24 healthy adults, who they presented with two lists of 10 words that the two-dozen people were asked to memorize. The two lists of 10 words were shown separately one dozen times. Following a short task created to distract the participants, the collective of participants was then asked to recall all the words from the two lists they'd just seen. Then, while the participants were regurgitating the words back to the researchers, half of them were besieged with a single hertz of slow repetitive transcranial magnetic stimulation (rTMS), directly into their prefrontal cortex. The other half of participants received one hertz of rTMS, but to the top of their head.
Magnetic stimulation of the DLPFC could help future treatments of dementia
There were no reports of a stinging sensation. But compared to participants of the control group, the people who received magnetic stimulation to the DLPFC more recalled the words with greater accuracy. Notably, while the stimulation didn't have an apparent effect in helping the participants remember the order of the words, it did help them recall each word, albeit out-of-order. The researchers say we should take this with a grain of salt, since the recent study only involved two dozen healthy adults. But the recent study aligns with earlier findings from the 2014 study, and also supports other studies that explore DLPFC, and its function in memory formation.
Earlier studies that actively stimulated the DLPFC showed a drop in memory performance, but rTMS is the distinguishing feature. It's a slow kind of stimulation that tends to inhibit most of the cortex, instead of exciting it. And rTMS' inhibitory nature has recently emerged as an exciting new treatment for potentially quieting the mind of people with major depressive disorder. This ability to inhibit the cortex could even ripple outwards from the DLPFC to an adjacent region of the brain, called the parietal cortex. This part of the brain plays a role in perception and attention, and when activity here is reduced, our ability to focus and perform memory retention exercises improves, according to brain imaging studies. "Our electrophysiological results suggest that frontal stimulation affects a wider network and improves memory formation by inhibiting parietal areas," said a University of Glasgow Neuroscientist, named Micea van der Plas, in a Science Alert report. While these effects are highly compelling, especially in the pursuit of potential treatments for side effects of major depression, and perhaps even dementia, the results of this study need further analysis, verification, and expansion, before anything can be designed, and one day hit the market.