In English, Dutch, and other Germanic languages the initial phonological unit used in word production has been shown to be the phoneme; conversely, others have revealed that in Chinese this is the atonal syllable and in Japanese the mora. The current paper is, to our knowledge, the first to report chronometric data on Vietnamese phonological encoding. Vietnamese, a tonal language, is of interest as, despite its Austroasiatic roots, it has clear similarities with Chinese through extended contact over a prolonged period. Four experiments (i.e., masked priming, phonological Stroop, picture naming with written distractors, picture naming with auditory distractors) have been conducted to investigate Vietnamese phonological encoding. Results show that in all four experiments both onset effects as well as whole syllable effects emerge. This indicates that the fundamental phonological encoding unit during Vietnamese language production is the phoneme despite its apparent similarities to Chinese. This result might have emerged due to tone assignment being a qualitatively different process in Vietnamese compared to Chinese.
Are letters with a diacritic (e.g., â) recognized as a variant of the base letter (e.g., a), or as a separate letter identity? Two recent masked priming studies, one in French and one in Spanish, investigated this question, concluding that this depends on the language-specific linguistic function served by the diacritic. Experiment 1 tested this linguistic function hypothesis using Japanese kana, in which diacritics signal consonant voicing, and like French and unlike Spanish, provide lexical contrast. Contrary to the hypothesis, Japanese kana yielded the pattern of diacritic priming like Spanish. Specifically, for a target kana with a diacritic (e.g., ガ, /ga/), the kana prime without the diacritic (e.g., カ, /ka/) facilitated recognition almost as much as the identity prime (e.g., ガ–ガ = カ–ガ), whereas for a target kana without a diacritic, the kana prime with the diacritic produced less facilitation than the identity prime (e.g., カ–カ < ガ–カ). We suggest that the pattern of diacritic priming has little to do with linguistic function, and instead it stems from a general property of visual object recognition. Experiment 2 tested this hypothesis using visually similar letters of the Latin alphabet that differ in the presence/absence of a visual feature (e.g., O and Q). The same asymmetry in priming was observed. These findings are consistent with the noisy channel model of letter/word recognition.