The ancient Greeks prayed to the muses for creative inspiration.  (They also practiced alchemy and believed the human body was made of four humors.)  And while our understanding of science has become more refined over the millennia, the source of creativity is as mysterious to us today as it was in the age of mythical gods and goddesses.  That might be about to change, though, as science tunes in to the human brain – at play.  The Signal’s Aaron Henkin reports…