Hector Aguilar puts the cat among the pigeons:

>Then my question is, what about "modern" classical music? What does
>the new appreciation of some of the less tonal composers say about
>brain function?

In the absence of evidence or any real physical understanding of how the
mind appreciates art, absolutely nothing.

> I think this is a legitmate question, because a lot of people-- smart
>people-- who like "classical" music are not that enthralled by Bartok or
>Piston (I know some of you might not consider Bartok and Piston "modern",
>but for the purposes of this posting let us please agree that they are!).

Hey, a lot of very smart people don't like classical music at all.
Furthermore, some who like Medieval, Renaissance, and Modern music don't
like Classical or Romantic.  I'm sure there are various permutations
of this.  Until we can account for several non-musical factors that
have arisen in the culture since the 20th century began regarding the
dissemination of classical music, there's absolutely no valid leap one
can yet make about the nature of music -- tonal or atonal, Common Practice
period or not -- in esse.

> So, if I've been a lifelong adherent of tonality, and then one day
>I realize that Haydn,Mozart and Bach are kind of boring, but instead of
>finding an interest in pop music I gravitate towards Bartok and the like,
>does this mean that a change has occured in my cognitive functions? And if
>so, in what direction?

Again, who knows? I'll ask another question:  the first time you read
Sophocles, did you completely understand it? The corollary to this question
is -- and I'll undoubtedly get flack for saying this -- that, God forbid,
you may have learned something about listening to other, less familiar
music, rather than have had an immediate, intuitive spark ignite your soul,
Which As We All Know, All Great Art Generates.

Steve Schwartz