What is Synesthesia?

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At least 3 percent of the population is thought to have some form of synesthesia—the phenomenon of blended senses, where a stimulus, like letters or numbers, can trigger a nominally unrelated sensation, like color or sound. Neuroscientist David Eagleman explains some of the amazing forms synesthesia can take, and the surprising advantages it grants to some people, in this clip from “What Is Color?,” a program of the 2014 World Science Festival.

[Source: World Science Festival YouTube link]