My copy isn't so near, but I think my "intuitions" were informed somewhere in one of his "Reverse Engineering the Human Brain" sections. (Sorry I can't provide a more precise reference.)

His book is well footnoted, and if there are in fact scientific studies reinforcing what I claim to remember him having written, I'm sure they would be documented there.

If you haven't read it, and your looking for some hyper-tech sort of inspiration, I highly recommend it. It is maybe a bit exhaustive for the casual reader, but well worth it considering it's detail and scope.

(And my apologies to RayK if I'm entirely mistaken in my understanding.)