Electric Brain Stimulation Can Improve Working Memory in Older Adults, BU Study Shows
Boston, MA– Researchers at Boston University have published a paper suggesting that working memory can be improved, at least for an hour, if we’re willing to wear an electrode-covered cap on our scalps. Ideally the technology would someday function more discreetly, but for now, the results on memory improvement are encouraging.
As we get older, we have a harder time holding onto or processing new information due to the loss of working memory, a form of short-term memory. Jonathan Lambert at WGBH explains that normally the brain can store information in one part of the brain for several seconds while accessing different areas for decision-making or planning. However, as our brains age, they’re less capable of coordinating the different areas together.
One theory for why working memory fades is that the different areas of the brain are no longer on the same wavelength. They’re firing, but they’re out of sync. In this study, BU neuroscientist and lead researcher Robert Reinhart decided to test what would happen if he stimulated areas of the brain so that they fired in unison, using transcranial stimulation with weak electrical currents while monitoring the results on an EEG.
The paper, published in the journal Nature Neuroscience, is titled, “Working memory revived in older adults by synchronizing rhythmic brain circuits.” The study found that after electrical brain stimulation to synchronize the brain waves in the prefrontal and temporal cortex, older adults’ working memory functioned on the level of younger adults, and the effects lasted for at least 50 minutes after the experiment.
The experiment asked 42 individuals in their 60s and 70s who were cognitively healthy to view a series of images of everyday items, each one followed by an exact match or a slightly altered image of the same object, with the goal of identifying which images matched and which were different.
Reinhart said, “In terms of this working memory task, we made the brain of a 70-year-old look like that of a 20-year-old.”
Interestingly, the experiment also modified the brain waves of younger research participants, demonstrating the effect on working memory in a younger brain that received an electrical impulse to desynchronize their brain waves. When their waves were desynchronized, the younger participants showed the same degraded working memory as the older adults before they’d experienced the electrical current.
While more research is needed to confirm that the results can be replicated and to determine the duration of the effects, Reinhart says that this is the first time that the link has been made between disconnected brain areas and working memory failures in older adults. This could be key to future discoveries related to cognitive enhancement.