25 minutes of non-invasive electrical brain stimulation was able to improve working memory by restoring electrical activity between two brain regions (prefrontal and temporal) in elderly people.

The memory improvements lasted an hour after the treatment and matched the performance of younger participants.

This was a small study with only 42 people and the effects only lasted an hour but it is an interesting proof-of-principle that electrical activity between two brain regions can be restored to a more youthful state and this improves working memory. Much more work is needed but this is an exciting preliminary finding.