Mental stimulation and Alzheimer's

Some recent research suggests that mental stimulation does stave off the onset of Alzheimer's, but the final deterioration is faster. This would be consistent with the disease beginning at the same time in both samples (mentally active and inactive), but that the mentally active group's brains "rewire around" the damage until it becomes too great. We know the brain is somewhat "plastic," and can reorganize to a surprising degree: see an early story and the followup on London cabdriver brains.

It might be interesting to compare brain activity and development between other different groups: parents and the childless (not involved in teaching or care); police and assembly-line workers; and so on.

I was going to write "police and nurses" but it occurred to me that both professions demand extreme attentiveness to details of other people's actions and appearance. The element of personal danger is much higher for the policeman, but an empathetic nurse might feel the danger to the patient too.