synaesthesia

1. (neurology, psychology) A neurological or psychological phenomenon whereby a particular sensory stimulus triggers a second kind of sensation.Examples: "M. [Théodore] Flournoy includes all the phenomena of "Colored Hearing" and of "Mental Forms" under the convenient and adequate name Synæsthesia—in place of which, to be sure, he himself usually employs the less defensible term Synopsie. […] The phenomena of synæsthesia are divided into three main groups: "photisms," among which are included, as by [Eugen] Bleuler and Lehmann, all the varieties of pseudo-chromesthesia; "Schemes," comprising not only "forms" (diagrammes) associated with series of words or numbers, but "symbols," or particular figures associated with single letters, numerals, colors and the like; and "personifications," in which the associated factor is no mere color or form, but has become richer and more concrete."; "Probably in all of us, though in some men much more distinctly than in others, there exist certain synæsthesiæ or concomitances of sense-impression, which are at any rate not dependent on any recognisable link of association."; "[…] R. H. Gault's case of synesthesia in a deaf and blind girl, who could distinguish colors by the sense of smell, […]"countableuncountable

2. (by extension) The association of one sensory perception with, or description of it in terms of, a different perception that is not experienced at the same time.Examples: "On a phonemic level, phenomena of synesthesia have often been described and studied. Practically all children and a good many adults—though for the most part adults will deny it—spontaneously associate sounds, whether phonemes or the timbre of musical instruments, with colors and forms."; "For one of the enigmatic features of synaesthesia is that, within a given cultural group, the kinds of associations made by different subjects occur according to statistically verifiable recurring patterns. As Jakobson explains, ‘when we ask whether /i/ or /u/ is darker, testing such phonic oppositions as grave vs. acute, some of the subjects may respond that this question makes no sense to them, but hardly one will respond that /i/ is the darker of the two’[…]."broadlycountableuncountable

3. (art, literature) A literary or artistic device whereby one kind of sensation is described in the terms of another.Examples: "Linking moods with colours is one example of synaesthesia. […] As a tool for improving writing, the idea of synaesthesia is versatile and innovative. Why use only visual references to describe visual impressions? Why just describe sounds using sound-related words? Play with cross-matching the senses."; "[I]t may be stated that the concept of synaesthesia is instrumental for understanding music videos, since videos are based on the soundtrack's visual associations. Yet to discuss associations here may cause some problems. […] [Nicholas Cook] seems to be relying on a rather normative conception of synaesthesia, which for its part supports the idea of absolute, nonrepresentational music. The implication of his discussion is that the "true" forms of music–image synaesthesia come only in the forms of perception of color or light when hearing a certain musical sound."countableuncountable