I got the idea after reading the essays at the back of The Man Who Tasted Shapes by Richard E. Cytowic, MD. (read circa 1994) A lot of new ground-breaking research has been done into the brain. Some scientist now think it is our limbic region, and not the cortex, that makes humans different than other animals. The ability to have concepts such as love, money, and language where symbols stand for other things - some concrete and some abstratct. So without further ado...

The limbic region is the area of the brain where creative thought is spawned.