Synesthesia, << sihn ehs THEE zhuh, >> is an unusual perceptual condition in which the stimulation of one sense produces a mental impression associated with another sense or stimulus. For example, a person may report seeing shapes when listening to music. In one common form of synesthesia, a person sees colors associated with particular letters of the alphabet. A person with synesthesia is known as a synesthete << sihn ehs THEET >> .
A synesthetic sensation may be triggered by seeing a number, a letter, or a word. Such a sensation may also be caused by hearing a word, a voice, or music. Less commonly, synesthesia may be triggered by touch, taste, smell, or pain. The sensations themselves are often colors, but they may also be shapes, sounds, tastes, smells, or pains. Thus, a smell may arouse a sensation of sound, a word may arouse a flavor, or a pain may arouse a sensation of color. Synesthetic experiences are typically simple sensations rather than perceptions of fully realized objects.
Scientists have identified more than 60 forms of synesthesia. A person with synesthesia may experience just one of these forms or several of them. Synesthesia usually begins in childhood and can last a lifetime.
Most scientific studies of synesthesia have involved synesthetes in whom color sensations are triggered by letters of the alphabet. Such studies include monitoring brain activity in these synesthetes as they read or hear such letters. The studies reveal neural activity in regions of the brain associated with the perception of color as wells as in brain regions associated with letters or sounds. Such findings indicate that synesthesia is a genuine perceptual experience, although an unusual and harmless one.
Synesthesia tends to run in families. Researchers believe that as many as 1 in 25 people experiences some form of synesthesia. Synesthetes are especially likely to engage in creative activities, including painting, sculpture, architecture, music, dance, and writing. A synesthete may make use of the condition in creative works. Researchers believe many famous artists were synesthetes. These people include the Hungarian composer Franz Liszt , the American actress Marilyn Monroe , the Russian-born author Vladimir Nabokov , and the painters Wassily Kandinsky of Russia and Joan Mitchell of the United States.
See also Autonomous sensory meridian response (ASMR) .
