Four experiments investigated the role of the syllable in Chinese spoken word production. Chen, Chen and Ferrand (2003) reported a syllable priming effect when primes and targets shared the first syllable using a masked priming paradigm in Chinese. Our Experiment 1 was a direct replication of Chen et al.’s (2003) Experiment 3 employing CV (e.g., 拔营,/ba2.ying2/, strike camp) and CVG (e.g., 白首,/bai2.shou3/, white haired) syllable types. Experiment 2 tested the syllable priming effect using different syllable types: e.g., CV (气球,/qi4.qiu2/, balloon) and CVN (蜻蜓,/qing1.ting2/, dragonfly). Experiment 3 investigated this issue further using line drawings of common objects as targets that were preceded either by a CV (e.g., 企,/qi3/, attempt), or a CVN (e.g., 情,/qing2/, affection) prime. Experiment 4 further examined the priming effect by a comparison between CV or CVN priming and an unrelated priming condition using CV-NX (e.g., 迷你,/mi2.ni3/, mini) and CVN-CX (e.g., 民居,/min2.ju1/, dwellings) as target words. These four experiments consistently found that CV targets were named faster when preceded by CV primes than when they were preceded by CVG, CVN or unrelated primes, whereas CVG or CVN targets showed the reverse pattern. These results indicate that the priming effect critically depends on the match between the structure of the prime and that of the first syllable of the target. The effect obtained in this study was consistent across different stimuli and different tasks (word and picture naming), and provides more conclusive and consistent data regarding the role of the syllable in Chinese speech production.

An essential step to create phonology according to the language production model by Levelt, Roelofs and Meyer is to assemble phonemes into a metrical frame. However, recently, it has been proposed that different languages may rely on different grain sizes of phonological units to construct phonology. For instance, it has been proposed that, instead of phonemes, Mandarin Chinese uses syllables and Japanese uses moras to fill the metrical frame. In this study, we used a masked priming-naming task to investigate how bilinguals assemble their phonology for each language when the two languages differ in grain size. Highly proficient Mandarin Chinese-English bilinguals showed a significant masked onset priming effect in English (L2), and a significant masked syllabic priming effect in Mandarin Chinese (L1). These results suggest that their proximate unit is phonemic in L2 (English), and that bilinguals may use different phonological units depending on the language that is being processed. Additionally, under some conditions, a significant sub-syllabic priming effect was observed even in Mandarin Chinese, which indicates that L2 phonology exerts influences on L1 target processing as a consequence of having a good command of English.

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The degree to which phonological codes constrain handwriting is at present controversial. Two experiments used a picture-word interference paradigm in which participants wrote down the names of pictures while attempting to ignore visual distractor words presented at various time intervals (SOAs). Distractors could be orthographically and phonologically related, orthographically related only, or unrelated. We found an exclusive effect of phonology at an early SOA, and orthographic priming at a later SOA. In a second experiment, we showed that the effect of phonology was diminished when writers engaged in concurrent articulatory suppression. The results suggest a role of phonology in the generation of handwritten words that is to some extent dependent on situational circumstances.

Plant metacaspases mediate programmed cell death in development, biotic and abiotic stresses, damage-induced immune response, and resistance to pathogen attack. Most metacaspases require Ca2+ for their activation and substrate processing. However, the Ca2+-dependent activation mechanism remains elusive. Here we report the crystal structures of Metacaspase 4 from Arabidopsis thaliana (AtMC4) that modulates Ca2+-dependent, damage-induced plant immune defense. The AtMC4 structure exhibits an inhibitory conformation in which a large linker domain blocks activation and substrate access. In addition, the side chain of Lys225 in the linker domain blocks the active site by sitting directly between two catalytic residues. We show that the activation of AtMC4 and cleavage of its physiological substrate involve multiple cleavages in the linker domain upon activation by Ca2+. Our analysis provides insight into the Ca2+-dependent activation of AtMC4 and lays the basis for tuning its activity in response to stresses for engineering of more sustainable crops for food and biofuels.

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Is the production of written words affected by their phonological properties? Most researchers agree that orthographic codes can be accessed directly from meaning, but the contribution of phonological codes to written word production remains controversial, mainly because studies have focused on languages with alphabetic scripts, and it is difficult to dissociate sound from spelling in such languages. We report results from a picture-word interference task in which Chinese participants wrote the names of pictures while attempting to ignore written distractor words. On some trials, the distractors were phonologically and orthographically related to the picture names; on other trials, the distractors were only phonologically related to the picture names; and on still other trials, the distractors and picture names were unrelated. Priming effects were found for both types of related distractors relative to unrelated distractors. This result constitutes clear evidence that phonological properties constrain orthographic output. Additionally, the results speak to the nature of Chinese orthography, suggesting subsemantic correspondences between sound and spelling.

General rightsThis document is made available in accordance with publisher policies. Please cite only the published version using the reference above. Full terms of use are available: http://www.bristol.ac.uk/pure/about/ebr-terms AbstractPrevious studies of spoken picture naming using event-related potentials (ERPs) have shown that speakers initiate lexical access within 200 ms after stimulus onset. In the present study, we investigated the time course of lexical access in written, rather than spoken, word production. Chinese participants wrote target object names which varied in word frequency, and written naming times and ERPs were measured. Writing latencies exhibited a classical frequency effect (faster responses for high-than for low-frequency names). More importantly, ERP results revealed that electrophysiological activity elicited by high-and low frequency target names started to diverge as early as 168 ms post picture onset. We conclude that lexical access during written word production is initiated within 200 ms after picture onset. This estimate is compatible with previous studies on spoken production which likewise showed a rapid onset of lexical access (i.e., within 200 ms after stimuli onset). We suggest that written and spoken word production share the lexicalization stage.