The Emergence of a Phoneme-Sized Unit in L2 Speech Production: Evidence from Japanese-English Bilinguals

Phonological encoding in Tongan: An experimental investigation

This study is the first to report chronometric evidence on Tongan language production. It has been speculated that the mora plays an important role during Tongan phonological encoding. A mora follows the (C)V form, so /a/ and /ka/ (but not /k/) denote a mora in Tongan. Using a picture-word naming paradigm, Tongan native speakers named pictures containing superimposed non-word distractors. This task has been used before in Japanese, Korean, and Vietnamese to investigate the initially selected unit during phonological encoding (IPU). Compared with control distractors, both onset and mora overlapping distractors resulted in faster naming latencies. Several alternative explanations for the pattern of results-proficiency in English, knowledge of Latin script, and downstream effects-are discussed. However, we conclude that Tongan phonological encoding likely natively uses the phoneme, and not the mora, as the IPU.

Word learning and lexicalization in a second language: Evidence from the Prime lexicality effect in masked form priming

In a masked form priming lexical decision task, orthographically related word primes cause null or inhibitory priming relative to unrelated controls because of lexical competition between primes and targets, whereas orthographically related nonword primes lead to facilitation because nonwords are not lexically represented and hence do not evoke lexical competition. This prime lexicality effect (PLE) has been used as an index of new word lexicalization in the developing lexicon by using to-be-learned words and their orthographic neighbors as primes and targets, respectively. Experiment 1 confirmed an inhibitory effect of −46 ms among native English speakers and faciliatory effects of 52 ms by Japanese English learners without critical word training. In Experiment 2, Japanese English learners studied novel English words while performing a meaning-based, form-based, or no task during learning. Recall measures indicated a dissociation between these two types of processing, with a form-based task leading to greater recall of L2 words and a meaning-based task leading to greater recall of L1 words. Results indicated that all three learning conditions produced neither facilitation nor inhibition (null priming effect). Taken together, the results of the two experiments demonstrate that the PLE can occur in a second language (L2) and that the training procedure can yield at least partial lexicalization of new L2 words.

Phonological encoding in Vietnamese: An experimental investigation

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.

Orthographic properties of distractors do influence phonological Stroop effects: Evidence from Japanese Romaji distractors

In attempting to understand mental processes, it is important to use a task that appropriately reflects the underlying processes being investigated. Recently, Verdonschot and Kinoshita (Memory & Cognition, 46, 410-425, 2018) proposed that a variant of the Stroop task-the "phonological Stroop task"-might be a suitable tool for investigating speech production. The major advantage of this task is that the task is apparently not affected by the orthographic properties of the stimuli, unlike other, commonly used, tasks (e.g., associative-cuing and word-reading tasks). The viability of this proposal was examined in the present experiments by manipulating the script types of Japanese distractors. For Romaji distractors (e.g., "kushi"), color-naming responses were faster when the initial phoneme was shared between the color name and the distractor than when the initial phonemes were different, thereby showing a phoneme-based phonological Stroop effect (Experiment 1). In contrast, no such effect was observed when the same distractors were presented in Katakana (e.g., "くし"), replicating Verdonschot and Kinoshita's original results (Experiment 2). A phoneme-based effect was again found when the Katakana distractors used in Verdonschot and Kinoshita's original study were transcribed and presented in Romaji (Experiment 3). Because the observation of a phonemic effect directly depended on the orthographic properties of the distractor stimuli, we conclude that the phonological Stroop task is also susceptible to orthographic influences.

Syllable retrieval precedes sub-syllabic encoding in Cantonese spoken word production

Two experiments were conducted to investigate the time course of syllabic and sub-syllabic processing in Cantonese spoken word production by using the picture-word interference task. Cantonese-speaking participants were asked to name individually presented pictures aloud and ignore an auditory word distractor. The targets and distractors were either phonologically related (i.e., sharing two identical word-initial phonemes) or unrelated. In Experiment 1, the target syllables were all consonant-vowel (CV)-structured. The phonological distractor was either a CV syllable (i.e., Full Syllable Overlap) or a CVC (consonant-vowel-consonant) syllable (i.e., Sub-syllable Overlap). Relative to the unrelated control, Full Syllable Overlap distractors facilitated naming in all stimuli onset asynchronies (SOAs) (-175, 0, or +175 ms) whereas Sub-syllable Overlap distractors exhibited facilitation only at 0-ms and +175-ms SOAs. Experiment 2 adopted a similar design to examine the possible influence of syllabic structure similarity on the results of Experiment 1. The target syllables were all CVC-structured. The phonological distractor was either a CVC (i.e., Syllable-structure Consistent) or CV (i.e., Syllable-structure Inconsistent) syllable. Comparable priming was observed between the two distractor conditions across the three SOAs. These results indicated that an earlier priming effect was observed with full syllable overlap than sub-syllabic overlap when the degree of segmental overlap was held constant (Experiment 1). The earlier syllable priming observed in Experiment 1 could not be attributed to the effect of syllabic-structure (Experiment 2), thereby suggesting that the syllable unit is important in Cantonese and is retrieved earlier than sub-syllabic components during phonological encoding.

Orthographic and phonological priming effects in the same-different task

Masked priming tasks have been used widely to study early orthographic processes-the coding of letter position and letter identity. Recently, using masked priming in the same-different task Lupker, Nakayama, and Perea (2015a) reported finding a phonological priming effect with primes presented in Japanese Katakana, and English target words presented in the Roman alphabet, and based on this finding, suggested that previously reported effects in the same-different task in the literature could be based on phonology rather than orthography. In this article, the authors explain why the design of Lupker et al.'s experiment does not address this question; they then report 2 new experiments that do. The results indicate that the priming produced by orthographically similar primes in the same-different task for letter strings presented in the Roman alphabet is almost exclusively orthographic in origin, and phonology makes little contribution. The authors offer an explanation for why phonological priming was observed when the prime and target are presented in different scripts but not when they are presented in the same script. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Sumacku or Smack? The value of analyzing acoustic signals when investigating the fundamental phonological unit of language production

An ongoing debate in the speech production literature suggests that the initial building block to build up speech sounds differs between languages. That is, Germanic languages are suggested to use the phoneme, but Japanese and Chinese are proposed to use the mora or syllable, respectively. Several studies investigated this matter from a chronometric perspective (i.e., RTs and accuracy). However, a less attention has been paid to the actual acoustic utterances. The current study investigated the verbal responses of two Japanese-English bilingual groups of different proficiency levels (i.e., high and low) when naming English words and found that the presence or absence of vowel epenthesis depended on proficiency. The results indicate that: (1) English word pronunciation by low-proficient Japanese English bilinguals is likely based on their L1 (Japanese) building block and (2) that future studies would benefit from analyzing the acoustic data as well when making inferences from chronometric data.

Mora or more? The phonological unit of Japanese word production in the Stroop color naming task

In English, Dutch, and other European languages, it is well established that the fundamental phonological unit in word production is the phoneme; in contrast, recent studies have shown that in Chinese it is the (atonal) syllable and in Japanese the mora. The present study investigated whether this cross-language variation in the size of the unit of word production is due to the type of script used in the language (i.e., alphabetic, morphosyllabic, or moraic). Capitalizing on the multiscriptal nature of Japanese, and using the Stroop color naming task, we show that the overlap in the initial mora between the color name and the written distractor facilitates color naming independent of script type. These results confirm the mora as the phonological unit of word production in Japanese, and establish the Stroop color naming task as a useful task for investigating the fundamental (or "proximate") phonological unit used in speech production.

Dutch-Cantonese Bilinguals Show Segmental Processing during Sinitic Language Production

This study addressed the debate on the primacy of syllable vs. segment (i.e., phoneme) as a functional unit of phonological encoding in syllabic languages by investigating both behavioral and neural responses of Dutch-Cantonese (DC) bilinguals in a color-object picture naming task. Specifically, we investigated whether DC bilinguals exhibit the phonemic processing strategy, evident in monolingual Dutch speakers, during planning of their Cantonese speech production. Participants named the color of colored line-drawings in Cantonese faster when color and object matched in the first segment than when they were mismatched (e.g., 藍駱駝, /laam4/ /lok3to4/, “blue camel;” 紅饑駝, /hung4/ /lok3to4/, “red camel”). This is in contrast to previous studies in Sinitic languages that did not reveal such phoneme-only facilitation. Phonemic overlap also modulated the event-related potentials (ERPs) in the 125–175, 200–300, and 300–400 ms time windows, suggesting earlier ERP modulations than in previous studies with monolingual Sinitic speakers or unbalanced Sinitic-Germanic bilinguals. Conjointly, our results suggest that, while the syllable may be considered the primary unit of phonological encoding in Sinitic languages, the phoneme can serve as the primary unit of phonological encoding, both behaviorally and neurally, for DC bilinguals. The presence/absence of a segment onset effect in Sinitic languages may be related to the proficiency in the Germanic language of bilinguals.