title: Biases and regularities of grapheme-colour associations in Japanese nonsynaesthetic population.
abstract: Associations between graphemes and colours in a nonsynaesthetic Japanese population were investigated. Participants chose the most suitable colour from 11 basic colour terms for each of 40 graphemes from the four categories of graphemes used in the Japanese language (kana characters, English alphabet letters, and Arabic and kanji numerals). This test was repeated after a three-week interval. In their responses, which were not as temporally consistent as those of grapheme-colour synaesthetes, participants showed biases and regularities that were comparable to those of synaesthetes reported in past studies. Although it has been believed that only synaesthetes, and not nonsynaesthetes, tended to associate graphemes with colours based on grapheme frequency, Berlin and Kay's colour typology, and colour word frequency, participants in this study tended in part to associate graphemes with colours based on the above factors. Moreover, participants that were nonsynaesthetes tended to associate different graphemes that shared sounds and/or meanings (e.g., Arabic and kanji numerals representing the same number) with the same colours, which was analogous to the findings in Japanese synaesthetes. These results support the view that grapheme-colour synaesthesia might have its origins in cross-modal association processes that are shared with the general population.
authors.affiliation: a Department of Psychology , University of the Sacred Heart , Tokyo , Japan.
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Nagai
authors.affiliation: b Department of Psychology, Graduate School of Humanities and Sociology , The University of Tokyo , Tokyo , Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Yokosawa
authors.affiliation: c Department of Psychology, College of Contemporary Psychology , Rikkyo University , Saitama , Japan.
authors.forename: Michiko
authors.initials: M
authors.lastname: Asano
mesh_terms: D000293:Adolescent; D001244:Association; D015982:Bias; D003118:Color Perception / Q000502:physiology*; D005260:Female; D006801:Humans; D007092:Imagination; D007564:Japan; D007802:Language; D008433:Mathematics; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010468:Perceptual Disorders / Q000503:physiopathology; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology; D013223:Statistics as Topic; D011795:Surveys and Questionnaires; D000080311:Synesthesia; D055815:Young Adult
keywords: Grapheme–colour association; Grapheme–colour synaesthesia; Japanese population; Nonsynaesthetes; Synaesthesia