 This is Hidden Brain. I'm Shankar Vedantam. Norman Farb is a psychologist and neuroscientist at the University of Toronto. With Zindel Siegel, he's the author of Better in Every Sense, How the New Science of Sensation Can Help You Reclaim Your Life. Pop psychology talks a lot about the differences between the left brain and the right brain. But Norm says the more important distinction might be between the front of the brain and the back of the brain.