"Synesthesia is the blending or mixing of senses. A synesthete, for example, might see colors when listening to music or taste flavors when hearing a word. Dr. David Eagleman of Baylor College of Medicine explains this strange condition, and four synesthetes explain how they perceive the world."
http://www.researchchannel.org/prog/displayevent.aspx?fID=572&rID=29222
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