According to new research published in Nature Human Behaviour, slowing in response time can begin as early as age 20. However, this change can be explained by increased caution in decision making and slowing of non-decisional processes, as opposed to a slowing in mental speed. Slowing of mental speed was observed only after age 60.
Numerous research findings point to a negative association between mental speed and age, with older (vs. younger) people performing more slowly across various cognitive tasks. Most of the studies on the relation between age and mental speed have relied on average response time “in elementary cognitive tasks (for example, comparison of two letters) as a measure of basic speed of information processing,” write Mischa von Krause and colleagues.
