Mind & Brain Humans Possess Exotic Sensory Abilities Unusual cases reveal that the famous "five senses" are not as distinct as once thought By Ariel Bleicher THIS IS A PREVIEW. Buy this digital issue or subscribe to access the full article. Already a subscriber or purchased this issue? Sign In iStockPhoto For as long as he can remember, Bryan Alvarez has thought his mother resembled a Mark Rothko painting. The likeness is not just a metaphor he conjured up one day. Whenever he conceives of her name, Marla, he literally sees, in his mind's eye, blocks of colors, each one blending into the next—grainy, brick red for the M, bright, blood red for the A, eggplant purple for the R, plum purple for the L and red again for the final A. Growing up, Alvarez never thought it unusual that letters have inherent colors. He was in high school when he learned that his peers did not perceive the world as he did. Alvarez has a condition called synesthesia, in which otherwise normal people feel shapes when they taste foods, smell odors when they hear musical notes or see colors when they read words. THIS IS A PREVIEW. Buy this digital issue or subscribe to access the full article. Already a subscriber or purchased this issue? Sign In Buy Digital Issue $7.95 Add To Cart Browse all subscription options! Subscribe ADVERTISEMENT Scientific American is a trademark of Scientific American, Inc., used with permission © 2015 Scientific American, a Division of Nature America, Inc. All Rights Reserved.