Scientists conducted a small study to see if a non-invasive brain stimulation technique could improve working memory in healthy people. Working memory is what we use to hold and manipulate information in our minds for short periods, like remembering a phone number. The technique, called dual-target high-definition transcranial alternating current stimulation (tACS), uses a gentle electrical current applied to the scalp to influence brain activity.
Forty-five healthy volunteers participated. They received either the real dual-target stimulation, a different single-target version, or a fake 'sham' stimulation that felt similar but had no effect. Participants then performed memory tests. The group that received the dual-target stimulation performed better on these tests, particularly when the tasks were more difficult. Brain scans also showed changes in activity and connectivity in areas related to memory.
This was a controlled trial, which is a strong study design, but it was small and only included healthy individuals. The researchers did not report specific numbers on how much memory improved, nor did they share information about side effects or how tolerable the stimulation was. Because of this, we cannot yet know how reliable or meaningful these improvements are for everyday life.
Readers should view this as an interesting early step in brain research. The study suggests this specific stimulation method might influence memory circuits, but it is far from being a proven tool. Much larger and longer studies, including in people who actually have memory difficulties, are needed before we can understand any potential benefits or risks.