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, EXACTLY?

Synesthesia is a brain condition that may link a person’s senses together in an uncommon manner. For example, sounds might be heard but also seen, or flavors that can be tasted are also visualized. As the inimitable Dr. Oliver Sacks explained to American Public Media in 2009, the effect is “almost as if there’s some excessive connection, or abnormal connection between sensory areas which are normally separate.”

Every synesthete’s experience is different, but they generally fall into one of two types: projective or associative. Projective sensory experiences seem to present tangibly—say, a blob of red appears in the room, or the skin grows hot. Associative experiences draw to mind other concepts, moods, or memories.

The possible combinations of senses and stimuli are endless, but the most common types of synesthesia include grapheme-color synesthesia, in which numbers or letters bring about certain colors; chromesthesia, in which sounds (and often music) bring about colors; spatial sequence synesthesia, in which a person’s sense of a number is aligned in their sense of surrounding space; and number form synesthesia, which can bring up a mental map of numbers.

DIAGNOSIS

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 body.
  • 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 “Laura.”

WHAT’S SYNESTHESIA LIKE?

Whether it’s seeing a patch of mauve hanging in the air during a Metallica encore or simplyknowing that the number 12 is green, each synesthete’s special sensory link is different.Pitchfork explains that, in the mind of Duke Ellington, “a D note looked like dark blue burlap [and] a G was light blue satin,” while a young Pharrell Williams saw baby blue and burgundy hues when he first heard the music of Earth, Wind & Fire.

Synesthesia researcher Dr. Carol Crane feels guitar music “[brush] softly against her ankles” and hears trumpets as they “make themselves known on the back of her neck,” she toldMonitor on Psychology. Day, the ASA president, who is also a linguistics professor in Taiwan, told the publication that, for him, the taste of steak incites “a rich blue,” while steamed gingered squid “produces a large glob of bright orange foam, about four feet away, directly in front of me.”