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Diseases & Conditions - Synesthesia

  1. What is synesthesia?

    Synesthesia is a neurological condition in which one sense, such as hearing, is simultaneously perceived by one or more additional senses such as sight. The word synesthesia comes from two Greek words, syn (together) and aisthesis (perception); literally, “joined perception.” People who report such experiences are known as synesthetes.

  2. What are the symptoms?

    Synesthesia can involve any of the senses. The most common form occurs when someone sees a certain color in response to a certain letter of the alphabet or number. For example, a synesthete might see the word “plane”as green or the number “4” as brown. Some synesthetes hear sounds in response to smell, who smell in response to touch or feel something in response to sight.

  3. Who has it?

    Most synesthetes are born with this condition. There has been only one previously reported case of someone acquiring synesthesia as a result of an accident or other medical condition such as a stroke. This is the first reported case of acquired synesthesia manifesting itself in multiple senses.

    Some celebrated people who may have had developmental synesthesia (meaning they were born with it) include:

    • Russian author Vladimir Nabokov describes his relationship with letters and colours, which he called “coloured hearing,” in his autobiography, Speak, Memory : “The long a of the English alphabet ... has for me the tint of weathered wood, but the French a evokes polished ebony. This black group also includes hard g  (vulcanized rubber) and (a sooty rag being ripped).”

    • British painter David Hockney , who perceives music as color, shape, and configuration, and who uses these perceptions when painting opera stage sets but not while creating his other artworks

    • Duke Ellington, who saw notes in colours and textures. Saxophonist Harry Carney playing D was dark blue burlap, while Johnny Hodge playing G was light blue satin

    • Billy Joel, who associates musical genres and letters -- particularly vowels -- with color. He has said that softer, more intimate songs such as “Lullaby (Goodnight My Angel)” and “And So It Goes,” are blues or greens, while songs with a heavier beat and faster rhythm such as “It’s Still Rock n Roll to Me” suggest the red-orange-yellow end of the spectrum.

    • The only previously reported case of acquired synesthesia was a 35-year-old American woman who felt tingling on her body in response to sounds after suffering a stroke.

  4. What causes it?

    Scientists believe that synesthesia results from “crossed-wiring” in the brain. They hypothesize that in synesthetes, neurons and synapses that are supposed to be contained within one sensory system cross to another sensory system.