Several things based on my experience with people with Dementia:
Living alone makes it worse
Refusing to learn new things makes it worse
Refusing to socialize makes it worse
Endless amounts of TV makes it worse, even if it is just background noise
Doing research makes it better
Exercise makes it better
Doing things that are hard for you to do makes it better
Something to the effect of establishing new neural pathways mitigates the disease. The opposite could be considered atrophy.