Ageing: Mental speed stays high until age 60

Mental processing speed does not start to decline until age 60, according to analysis of over a million participants in a paper published in Nature Human Behaviour. These findings challenge previous assumptions that mental speed peaks at age 20.

As we age, it generally takes us longer to react to changes in our environment, or stimuli. This slowing of response time starts from the age of about 20, gradually continuing to increase as we get older.

Mischa von Krause and colleagues analysed data from over one million participants who had taken part in an online experiment that measured their reaction times to a cognitive task. Participants had to categorize a selection of words and images that flashed up on a screen by pushing the correct key in response. The authors found that — although response times did start to slow after age 20 — this could be attributed to increases in decision caution and to slower non-decisional processes, such as time taken to press the key. The mental process of making the decision as to the correct answer, however, did not start to slow down until age 60, after which it progressively declined.

The authors conclude that, despite a widespread belief in age-related slowdowns in mental speed, their findings highlight how for much of our lives, and during the timespan of a typical career, this is not likely to be the case.