Smarts or just different wiring?

NPR's Radiolab aired an interesting bit about how the mind works, and featured Bob Milne's "A 4-Track Mind", alongside a piece called "Inner Voices".

What's been interesting about the Bob Milne bit is its discussion of ragtime music, of historical interest to me.  Please do give this presentation a listen, as it discusses the different layers of timing between left hand and right hand when playing rag. I have no doubt that the invention of the player piano assisted those who could play the piano but not like that.  It brings about a fuller appreciation of the genius of Scott Joplin, among others.  It also explains (to me, at least) why Debussy attempted "Gollywog's Cakewalk", a complete departure from the usual classical compositions.

I have to wonder if Alzheimer's might become an issue eventually, as Bob advances in age. I know that even though my dad was bright (college math teacher, chemist, electronics teacher to the military, English was second language), it was for him--as it is for me, given the genetic factor.  He forgot his mother tongue altogether in his 80s.  "If you don't use it, you lose it".  Generally true, but especially true of Alzheimer's victims who will even lose what they do use.