Graphemes Sharing Phonetic Features Tend to Induce Similar Synesthetic Colors

Abstract

Individuals with grapheme-color synesthesia experience idiosyncratic colors when viewing achromatic letters or digits. Despite large individual differences in grapheme-color association, synesthetes tend to associate graphemes sharing a perceptual feature with similar synesthetic colors. Sound has been suggested as one such feature. In the present study, we investigated whether graphemes of which representative phonemes have similar phonetic features tend to be associated with analogous synesthetic colors. We tested five Korean multilingual synesthetes on a color-matching task using graphemes from Korean, English, and Japanese orthography. We then compared the similarity of synesthetic colors induced by those characters sharing a phonetic feature. Results showed that graphemes associated with the same phonetic feature tend to induce synesthetic color in both within- and cross-script analyses. Moreover, this tendency was consistent for graphemes that are not transliterable into each other as well as graphemes that are. These results suggest that it is the perceptual—i.e., phonetic—properties associated with graphemes, not just conceptual associations such as transliteration, that determine synesthetic color.

Why is the synesthete's “A” red? Using a five-language dataset to disentangle the effects of shape, sound, semantics, and ordinality on inducer–concurrent relationships in grapheme-color synesthesia

“…However, using the framework of Asano and Yokosawa (2013), it is also possible that in Korean other EFs are more salient than the ordinal EF. For example, the exceptional amount of structure in the orthography-to-c o r t e x 9 9 ( 2 0 1 8 ) 3 7 5 e3 8 9 phonology relationship in Hangul (Hangul is the only commonly-used featural orthography) might lead the Acoustic EF to play a larger role (indeed, this has been reported in Kang et al, 2017). If the Acoustic EF causes graphemes encoding sounds similar to "ㄱ"(/g/) to be associated with a similar color to "ㄱ", then the distinctiveness of "ㄱ"(/g/) would be reduced.…”

“…There is also mixed evidence that acoustic similarity exerts second-order effects: similarly-pronounced letters are associated with similar colors in Japanese (Asano & Yokosawa, 2011) and Korean (Kang, Kim, Shin, & Kim, 2017), but not in English (Watson et al, 2012).…”

“…Some Explanatory Factors might exert more influences in languages with particular properties. For example, the Acoustic EF correctly predicts inducereconcurrent relationships in Japanese Hiragana characters (Asano & Yokosawa, 2011) and Korean Hangul characters (Kang et al, 2017), but not in English letters (Watson et al, 2012). Asano and Yokosawa (2013) propose a model for this discrepancy that invokes the linguistic property of orthographic depth e the degree to which graphemes' pronunciation is consistent and predictable.…”

Do the colors of your letters depend on your language? Language-dependent and universal influences on grapheme-color synesthesia in seven languages.

“…As with the Color Name RF, one potential confound is that a stronger RF in Korean overpowers any influence of the Index Route. For example, Hangul is a "featural" alphabet that is heavily structured around sound (Haarmann, 1993), and sound similarity exerts a very strong influence on Korean grapheme-color associations (Kang et al, 2017), and the predictions of this RF could be particularly incongruent with those of the Index Route. We also noticed that some statistical features of the Index Route data itself seemed to be related to RF strength.…”

Synaesthetic colour associations for Japanese Kanji characters: from the perspective of grapheme learning

“…Such regularities provide important clues for clarifying mechanisms underlying synaesthesia. Previous studies have shown that psycholinguistic factors, such as grapheme frequency or familiarity [11,27,28], visual shape [12,15,29], grapheme sound [9][10][11]30], positions in a grapheme sequence (ordinality, [11,15,28,31]), and meaning or concepts [10,13,32], contribute to forming the synaesthetic colours for graphemes, suggesting that grapheme-colour synaesthesia is a fundamentally psycholinguistic phenomenon.…”