RESUMEN
Synesthesia is a condition in which the perception of a stimulus in one modality automatically triggers a secondary sensation in another modality or processing stream. Our study focused on grapheme-color synesthesia, in which the visual perception of letters or numbers (graphemes) induces a specific color sensation (the synesthetic color). Grapheme-color synesthetes do not typically experience colors for novel graphemes. However, synesthetic colors associated with familiar graphemes can be transferred to graphemes learned later, even in adulthood. A previous study has shown that such a transfer can take place after only a 10-min writing exercise. In this study, we found that this immediate transfer occurs only when the synesthetic colors for familiar graphemes contribute to the discrimination of the graphemes to be learned. Synesthetes learned six novel graphemes, each of which was arbitrarily associated with one of six familiar graphemes. Half of the synesthetes were assigned to the heterogeneous condition, in which the synesthetic colors of one group of familiar graphemes were different from one another. The other half of the synesthetes were assigned to the homogeneous condition, in which the various colors of a whole group of familiar graphemes were categorically the same. After this learning session, less transfer of synesthetic colors to novel graphemes from the corresponding familiar graphemes occurred in the homogeneous condition than in the heterogeneous condition. These results support the view that synesthetic colors for graphemes may function as a grapheme acquisition aid.
Asunto(s)
Aprendizaje por Asociación , Percepción de Color , Sinestesia/psicología , Adulto , Femenino , Humanos , MasculinoRESUMEN
One of the fundamental questions about grapheme-colour synaesthesia is how specific associations between the graphemes and colours are formed. We addressed this question by focusing on the determinants of synaesthetic colours for Japanese Kanji characters (logographic characters) using a psycholinguistic approach. Study 1 explored the influence meaning has on synaesthetic colours for Kanji characters representing abstract meanings by examining synaesthetic colours for antonym pairs (i.e. characters with meanings opposed to each other) in Japanese synaesthetes. Results showed that semantic relations influenced the grapheme-colour associations for characters representing abstract meanings in the early stages of learning abstract Kanji, while the influence was reduced in the grapheme-colour associations for those learned later. Study 2 examined the effect that learning new sounds or meanings of graphemes has on synaesthetic colours for those graphemes. Japanese synaesthetes were taught new sounds or new meanings for familiar Kanji characters. Results indicated that acquiring new information for graphemes slightly but significantly reduced the test-retest grapheme-colour association consistency, suggesting that synaesthetic colours can be modulated to reflect the synaesthete's latest knowledge about graphemes. Implications of these findings are discussed from the perspective of the relationship between synaesthesia and grapheme learning. This article is part of a discussion meeting issue 'Bridging senses: novel insights from synaesthesia'.