As you read this article, you may not be consciously trying to memorize each sentence, but the words do need to stick around temporarily. After all, you have to remember what you just read to understand the full article. This is your working memory, sometimes called “short-term memory,” and it allows us to remember things just long enough to complete a task. Its decline is associated with dementia, Alzheimer’s disease, and regular aging. But scientists at Boston University think they’ve found a way to revive sluggish short-term memory.
The brain is full of tiny electric impulses that convey messages between neurons at different speeds and working memory is thought to rely on the synchronization of these signals. As a person gets older, or develops a memory-related disease, these signals fall out of step, so re-synchronizing them could restore memory to a younger, healthier state. The team of scientists used transcranial alternating-current stimulation (tACS)—small electric currents that course into the brain from the head’s surface—to target specific brain regions in a group of adults in their 60s and 70s for just under 30 minutes. After tACS, their previously-asynchronous signaling improved, and their accuracy on a memory-related task improved by approximately 10%, making it comparable to young adults’ performance.
tACS is still an imprecise method, but these findings suggest that memory loss isn’t as inevitable as we think. And improvement wasn’t limited to the 70-year-olds – when 20-year-olds with relatively poor memory for their age received tACS, their performance on the task improved by just under 10% as well, showing that a little zap may help people of any age. With more studies that delve into how this electric stimulation affects the brain, tACS could help people stay sharp throughout their lifespan.
Managing Correspondent: Aparna Nathan
Original article: Working memory revived in older adults by synchronizing rhythmic brain circuits – Nature Neuroscience
Media coverage: To Improve Memory, Tune It Like an Orchestra – New York Times
Scientists reverse memory decline using electrical pulses – The Guardian
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