Ever caught a whiff of the color blue? Or tasted a symphony? If that sounds completely bonkers to you, you’re in the majority. But for a small slice of humanity, these cross-sensory experiences are ...

Pupil size in people with synesthesia changed depending on how bright or dark the perceived colors were.

Ever since I can remember, numbers have appeared to me in specific colors. The number 2 is baby pink, 3 is sunshine yellow, 4 is royal blue-the list goes on. Its not just that they look a certain way, ...

Vladimir Nabokov first noticed, at age 7, his special gift of synesthesia when playing with colorful alphabet blocks that "were all the wrong color." Source: Contributor: Neil Overy/Alamy Stock Photo.