Electrical brain stimulation using a non-invasive cap can help boost older people’s mental scores to those of people 20-30 years younger, according to a US study.

Age-related decline in working memory can be reversed by stimulating two key brain areas at a specific rhythm, the researchers say in Nature Neuroscience.

The findings are early and only relate to healthy volunteers at this stage, but they could point to ways to boost brain function in people with age-related cognitive decline, such as dementia and Alzheimer’s disease.

Using transcranial alternating-current stimulation, researchers stimulated the brains of a group of young and old people, and were able to modulate the brainwave interactions linked to their working memory.