synæsthesia

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.