On Monday, scientists reported that brief sessions of specialized brain stimulation could reverse this steady decline in working memory, at least temporarily. The stimulation targeted key regions in the brain and synchronized neural circuits in those areas, effectively tuning them to one another, as an orchestra conductor might tune the wind section to the strings.
The findings, reported in the journal Nature Neuroscience, provide the strongest support yet for a method called transcranial alternating current stimulation, or tACS, as a potential therapy for memory deficits, whether from age-related decline, brain injury or, perhaps, creeping dementia.
In the new study, Robert M.G. Reinhart and John A. Nguyen, neuroscientists at Boston University, invited two groups of subjects, young adults and people in their 60s and 70s, to the lab for baseline measures of their neural firing rhythms. The scientists tailored the tACS program to optimize rhythmic “coupling” between frontal and temporal cortex areas in each individual’s brain. These brain regions specifically support working memory.
After 25 minutes of gentle stimulation, delivered by electrodes built into a skullcap, the older subjects performed just as well on memory tests as young adults.
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The participants tested their own working memories repeatedly, completing 10 sessions on a computer-based program that mimicked the old Highlights magazine game: stare at an image, then decide if subsequent images are identical or have subtle differences.
They performed under several conditions, including without stimulation; with “sham” stimulation, as a placebo control; and with the targeted tACS. Young people reliably outperformed their elders in the no-stimulation and sham conditions. But with the aid of the tACS, the older participants did just as well as their younger counterparts. And their working memory remained sharp for as long as the researchers continued testing it, for 50 minutes.
Reinhart said the findings “show us that negative, age-related changes in working memory are not unchangeable.”
This article originally appeared in The New York Times.