Four days of brain stimulation improved memory for a month

Researchers at Boston University applied a mild, non-invasive electrical current to the scalp of older adults for 20 minutes a day across four consecutive days, targeting brain regions tied to two different kinds of memory, and tested recall afterward.

Stimulating the parietal cortex at a low frequency improved working memory, the ability to briefly hold and manipulate information, while stimulating the prefrontal cortex at a higher frequency improved long-term memory recall instead. Adults aged 65 to 88 who started with weaker memory showed the largest and most durable gains.

Both improvements were still measurable a full month after the four-day stimulation ended, well beyond the treatment window itself, suggesting the brain's underlying plasticity had genuinely shifted rather than producing a brief, temporary boost. The device used mild alternating current through the scalp, not surgery, though the long-term safety of repeated sessions and whether gains persist beyond a month are still being studied.

Four days of current, a month of better memory.