This article is about the perceptual phenomenon. For the piano keyboard video game, see Synthesia. This article cites its sources projective methods of research of the child does not provide page references.
How someone with synesthesia might perceive certain letters and numbers. Synesthesia is a perceptual phenomenon in which stimulation of one sensory or cognitive pathway leads to automatic, involuntary experiences in a second sensory or cognitive pathway. In one common form of synesthesia, known as grapheme-color synesthesia or color-graphemic synesthesia, letters or numbers are perceived as inherently colored. Little is known about how synesthesia develops.
It has been suggested that synesthesia develops during childhood when children are intensively engaged with abstract concepts for the first time. Only a few types of synesthesia have been scientifically evaluated. Awareness of synesthetic perceptions varies from person to person. Difficulties have been recognized in adequately defining synesthesia.
Some synesthetes often report that they were unaware their experiences were unusual until they realized other people did not have them, while others report feeling as if they had been keeping a secret their entire lives. The automatic and ineffable nature of a synesthetic experience means that the pairing may not seem out of the ordinary. Though often stereotyped in the popular media as a medical condition or neurological aberration, many synesthetes themselves do not perceive their synesthetic experiences as a handicap. To the contrary, some report it as a gift—an additional “hidden” sense—something they would not want to miss. Most synesthetes become aware of their distinctive mode of perception in their childhood.