Stroop phenomena in the Japanese language: the case of ideographic characters (kanji) and syllabic characters (kana).

Utilizing a unique feature of the Japanese languages--that besides two syllabic orthographies, which have identical pronunciations, words with the same pronunciation may also be written in an orthography composed of ideographic characters--we have conducted an investigation of Stroop phenomena. The fact that pronunciations of the three Japanese orthographies are identical means that, if there are any differences between them in the Stroop phenomena observed, we can place the locus of this interference effect in the perceptual process. Five color names were written in the ideographic characters (kanji) and the two syllabic orthographies (hiragana and katakana). Color-congruent cards and incongruent cards were utilized in a color-naming task and a word-reading task. Mean required times for the color-naming condition and the word-reading conditions were compared with those for control conditions. Stroop phenomena were observed in both ideographic and syllabic orthographies. Significant differences in mean required times were observed between the ideographic and syllabic orthographies but not between the two syllabic orthographies. Interferences in comparisons of Japanese orthographies and color patch control conditions were much smaller than in the case of Stroop's (1935) experiment. A "Reverse Stroop Phenomenon" was observed only in the case of kanji on incongruent cards in the word-reading condition. The results support the hypothesis that both ideographic characters (in this case, kanji) and colors are processed in a parallel fashion in the non-dominant right cerebral hemisphere, while syllabic or phonetic characters are processed in the dominant left cerebral hemisphere.