Over the past few years, neuroscientists have made the quite revolutionary discovery that at all ages the brain is plastic or flexible - that's to say it's shaped by experience, what we do and how we think.
The human brain of all ages is plastic, that is, it is shaped by what you do, what you learn and what you think, ... There is strong evidence that, particularly in the over-50s, the degree to which you retain your mental faculties depends on a number of simple behavioural factors.