In a recent interview for the New York Times, Lisa Feldman Barrett, Professor of Psychology at Northeastern University in Boston, offered some advice to older people to help them keep their cognitive skills as finely tuned as possible.

Challenge yourself, she urged, to learn new things on a regular basis – but don't just do so casually. Study any new topic hard, until you feel tired, stymied and frustrated. This level of exertion, she added, is associated with increases in the ease of communication within the brain and, as a result, cognitive skills will be enhanced.

Her advice is based on a study of "superagers", individuals 65 years or older, whose cognitive skills are as acute as the average 25-year-old. Barrett believes that what sets superagers apart is their ability to use the unpleasant feelings they experience when challenging themselves as a signal to keep going, rather than as a warning to stop and rest.