Joined by synesthete, Sean Day Ph.D.  Synesthesia is a sensorial phenomenon whereby exposure to certain stimuli results in other senses being triggered.  For Sean, the sound of piano music evokes the visual experience of seeing a blue cloud floating, and tenor saxophones "look like" purple neon lights.  Sean describes some of the most interesting cases he's seen during his years of research. Dr. Drew and Dr. Bruce discuss the mechanisms by which the brain produces these sensorial perceptions. Sean's book: The Synesthete's Handbook. Sponsored by Bergamet Pro Plus.