Do you taste strawberries when you hear the sound of a guitar? Are you convinced that Fridays are
Yellow? When you see the number 7 do you see it in Light blue? Approximately 2%–4% of the
population has some form of synesthesia, perhaps you do, too!
What is synesthesia?
Synesthesia is a perceptual condition in which one sense (for example, hearing) is simultaneously
perceived as if by one or more additional senses such as sight. Another form of synesthesia joins
objects such as letters, numbers or shapes with a sensory perception such as smell, color or flavor.
Synesthesia can involve any of the senses. The most common form, colored letters and numbers,
occurs when someone always sees a certain color in response to a certain letter of the alphabet or
number. For example, seeing the word “dog” as forest green or the number “9! as light purple .
There are also synesthetes who hear sounds in response to smell, who smell in response to touch,
or who feel something in response to sight, Some even taste sound! Just about any combination of
the senses is possible.
Scientists hypothesize that in synesthetes, neurons and synapses that are “supposed” to be
contained within one sensory system cross to another sensory system. It is unclear why this might
happen but some researchers believe that these crossed connections are present in everyone at
birth, and only later are the connections refined. In some studies, infants respond to sensory
stimuli in a way that researchers think may involve synesthetic perceptions. It is hypothesized by
these researchers that many children have crossed connections and later lose them. Adult
synesthetes may have simply retained these crossed connections.
Although there is no officially established method of diagnosing synesthesia, some guidelines have
been developed by Richard Cytowic, MD, a leading synesthesia researcher. Not everyone agrees on
these standards, but they provide a starting point for diagnosis.
Synesthetes do not actively think about their perceptions; they just happen.
Rather than experiencing something in the “mind’s eye,” as might happen when you are
asked to imagine a color, a synesthete often actually sees a color projected outside of the
the perception must be the same every time; for example, if you taste chocolate when you
hear Beethoven’s Violin Concerto, you must always taste chocolate when you hear it; also,
the perception must be generic — that is, you may see colors or lines or shapes in response
to a certain smell, but you would not see something complex such as a room with people and
furniture and pictures on the wall.
Often, the secondary synesthetic perception is remembered better than the primary
perception; for example, a synesthete who always associates the color purple with the name
“Laura” will often remember that a woman’s name is purple rather than actually remembering