Andus Wing-Kuen Wong

Processing Segmental and Prosodic Information in Cantonese Word Production

Five experiments were conducted to investigate how subsyllabic, syllabic, and prosodic information is processed in Cantonese monosyllabic word production. A picture-word interference task was used in which a target picture and a distractor word were presented simultaneously or sequentially. In the first 3 experiments with visually presented distractors, null effects on naming latencies were found when the distractor and the picture name shared the onset, the rhyme, the tone, or both the onset and tone. However, significant facilitation effects were obtained when the target and the distractor shared the rhyme + tone (Experiment 2), the segmental syllable (Experiment 3), or the syllable + tone (Experiment 3). Similar results were found in Experiments 4 and 5 with spoken rather than visual distractors. Moreover, a significant facilitation effect was observed in the rhyme-related condition in Experiment 5, and this effect was not affected by the degree of phonological overlap between the target and the distractor. These results are interpreted in an interactive model, which allows feedback sending from the subsyllabic to the lexical level during the phonological encoding stage in Cantonese word production.

What are effective phonological units in Cantonese spoken word planning

Two picture—word interference experiments were conducted to investigate the nature of effective phonological units in Cantonese spoken word production. The names of the pictures were Cantonese monosyllables with a consonant 1 vowel 1 consonant (CVC) structure. Participants’ picture-naming responses were faster when the target (e.g., “star” /sing1/) and the distractor shared the same CVC component (e.g., /sing4/, meaning “city”), the same CV component (e.g., /sik6/, “eat”), or the same VC component (e.g., /ging2/, “region”), as opposed to when they were unrelated, and the facilitation effects observed were comparable in size. Also, similar facilitation effects were obtained across the CV1tone-related and the VC1tone-related conditions, whereas no reliable effect was found in the V1tone-related condition. These results indicate that an effective phonological unit in spoken word planning is neither a syllable (without tone) nor a segmental unit, and that the possible candidates lie between the two, at least in Cantonese.

Effects of practice schedules on speech motor learning

Abstract The aim of this study was to evaluate the effects of various practice schedules on learning a novel speech task. Forty healthy Cantonese speakers were asked to learn to produce a Cantonese phrase with two target utterance durations (2500 and 3500 milliseconds). They were randomly assigned to one of four learning conditions, each completing a different practice schedule, namely Blocked only, Random only, Blocked-then-Random, and Random-then-Blocked. Two retention tests (one immediate and one delayed) and a transfer test were administered. The four groups of participants showed different patterns of learning, but achieved comparable levels of performance at the end of the acquisition phase. However, participants in the Blocked only condition were less able to differentiate the two target durations than those in the Random only condition during retention. Furthermore, participants who received both blocked and random practice were less adversely affected by the secondary task during the transfer test than those who received either blocked or random practice alone. These findings suggest that mixed practice schedules are more effective than either blocked or random practice, especially in transferring the acquired speech motor skills to a cognitively demanding situation. The results have clinical implications regarding optimal practice schedules for treatment intervention.

Analogy Instruction and Speech Performance Under Psychological Stress

To examine the efficacy of explicit and implicit forms of instruction for speech motor performance under conditions of psychological stress. In experiment 1, 20 participants were asked to deliver a formal presentation to validate the modified Trier Social Stress Test (TSST). In experiment 2, 40 participants were instructed explicitly by verbal explanation or implicitly by analogy to speak with minimum pitch variation and were subjected to psychological stress using the modified TSST. Acoustic correlates of pitch height (mean fundamental frequency) and pitch variation (standard deviation of fundamental frequency) significantly increased in experiment 1 when participants delivered a speech under modified TSST condition. In experiment 2, explicitly instructed participants were unable to maintain minimum pitch variation under psychological pressure caused by the modified TSST, whereas analogy-instructed participants maintained minimal pitch variation. The findings are consistent with existing evidence that analogy instructions may result in characteristics of implicit motor learning, such as greater stability of performance under pressure. Analogy instructions may therefore benefit speech motor performance and might provide a useful clinical tool for treatment of speech-disordered populations.

Is Syntactic-Category Processing Obligatory in Visual Word Recognition? Evidence from Chinese.

Three experiments were conducted to investigate how syntactic-category and semantic information is processed in visual word recognition. The stimuli were two-character Chinese words in which semantic and syntactic-category ambiguities were factorially manipulated. A lexical decision task was employed in Experiment 1, whereas a semantic relatedness judgment task and a syntactic-category judgment task were adopted in Experiments 2 and 3, respectively. A semantic ambiguity disadvantage was observed in all three experiments, whereas a syntactic-category ambiguity disadvantage was only found in Experiment 3. In addition, no significant semantic ambiguity×syntactic-category ambiguity interaction was obtained across the three experiments. These results are consistent with the view that in isolated visual word recognition, the semantic information is crucial, but the syntactic-category information is not, at least in Chinese.

Limited role of phonology in reading Chinese two-character compounds: evidence from an ERP study.

This study investigates the role of phonology in reading logographic Chinese. Specifically, whether phonological information is obligatorily activated in reading Chinese two-character compounds was examined using the masked-priming paradigm with event-related potential (ERP) recordings. Twenty-two native Cantonese Chinese speakers participated in a lexical decision experiment. The targets were visually presented Chinese two-character strings and the participants were asked to judge whether the target in each trial was a legitimate compound word in Chinese. Each target was preceded by a briefly presented word prime. The prime and target shared an identical constituent character in the Character-related condition, a syllable in the Syllable-related condition, were semantically related in the Semantic-related condition, and were unrelated (both phonologically and semantically) in the control condition. The prime–target relationship was manipulated to probe the effects of word-form (i.e., character- or syllable-relatedness) and word-semantic relatedness on phonological (as indexed by an N250 ERP component) and semantic (as indexed by an N400 ERP component) processing. Significant and comparable facilitation effects in reaction time, relative to the control, were observed in the Character-related and the Semantic-related conditions. Furthermore, a significant reduction in ERP amplitudes (N250), relative to the control, was obtained in the Character-related condition in the time window of 150-250 ms post target. In addition, attenuation in ERP amplitudes was found in the Semantic-related condition in the window of 250-500 ms (N400). However, no significant results (neither behavioral nor ERP) were found in the Syllable-related condition. These results suggest that phonological activation is not mandatory and the role of phonology is minimal at best in reading Chinese two-character compounds.

Morpho-orthographic and morpho-semantic processing in word recognition and production: evidence from ambiguous morphemes

Two sets of experiments were conducted to investigate the role of morphemes in word recognition and production. These experiments employed three priming procedures (i.e., masked, unmasked and long lag) to study the relatively early to late stages of morphological processing. Targets were Chinese compound words containing an ambiguous morpheme (analogous to “chair” in “chairman” vs. “armchair”). Primes and targets shared the same ambiguous morpheme with the same interpretation (S), a different interpretation (D) or were completely unrelated (U). For word recognition, the facilitation by the S and the D primes was statistically identical in the masked priming procedure. But only the S primes continued to facilitate word recognition in the unmasked and the long-lag priming procedures. In contrast, for word production, only the D primes produced significant facilitation in masked priming. In unmasked priming, both the S and D primes facilitated the naming reaction times, as compared with the unrelated baseline. But the facilitation was stronger in the S than in the D conditions. Finally, in the long-lag priming procedure, both the S and the D primes produced facilitation of equal strength. These results indicate that the processing of ambiguous morpheme involves both morphemic form and meaning, and that the temporal dynamics of the two effects differ in recognition and production.

The processing of homographic morphemes in Chinese: an ERP study

ABSTRACT The processing of homographic morphemes during Chinese word recognition was investigated by recording event-related potentials (ERPs) in a masked priming lexical decision experiment. There were four conditions. In the morpheme condition, the homographic morphemes in primes and targets had the same interpretations (e.g. “公園-public garden/park” and “公眾-public people/the public”). In the homograph condition, they had different interpretations (e.g. “公雞-male chicken/cock”). Semantic-sharing (e.g. “草地-lawn”) and unrelated (e.g. “嗅覺-olfaction”) conditions were also included. Compared to the unrelated condition, the morpheme and homograph primes produced a comparable P200. In contrast, N400 priming was identified only in the morpheme condition. Semantic sharing produced relatively weaker effects. These findings indicate that homographic morphemes are activated during word recognition even though in principle, whole-word processing is more efficient. The results are discussed with reference to morpho-orthographic and morpho-semantic processing.

Examining the cognitive demands of analogy instructions compared to explicit instructions

Abstract Purpose: In many learning domains, instructions are presented explicitly despite high cognitive demands associated with their processing. This study examined cognitive demands imposed on working memory by different types of instruction to speak with maximum pitch variation: visual analogy, verbal analogy and explicit verbal instruction. Method: Forty participants were asked to memorise a set of 16 visual and verbal stimuli while reading aloud a Cantonese paragraph with maximum pitch variation. Instructions about how to achieve maximum pitch variation were presented via visual analogy, verbal analogy, explicit rules or no instruction. Pitch variation was assessed off-line, using standard deviation of fundamental frequency. Immediately after reading, participants recalled as many stimuli as possible. Result: Analogy instructions resulted in significantly increased pitch variation compared to explicit instructions or no instructions. Explicit instructions resulted in poorest recall of stimuli. Visual analogy instructions resulted in significantly poorer recall of visual stimuli than verbal stimuli. Conclusion: The findings suggest that non-propositional instructions presented via analogy may be less cognitively demanding than instructions that are presented explicitly. Processing analogy instructions that are presented as a visual representation is likely to load primarily visuospatial components of working memory rather than phonological components. The findings are discussed with reference to speech therapy and human cognition.

Primary phonological planning units in spoken word production are language-specific: Evidence from an ERP study

It is widely acknowledged in Germanic languages that segments are the primary planning units at the phonological encoding stage of spoken word production. Mixed results, however, have been found in Chinese, and it is still unclear what roles syllables and segments play in planning Chinese spoken word production. In the current study, participants were asked to first prepare and later produce disyllabic Mandarin words upon picture prompts and a response cue while electroencephalogram (EEG) signals were recorded. Each two consecutive pictures implicitly formed a pair of prime and target, whose names shared the same word-initial atonal syllable or the same word-initial segments, or were unrelated in the control conditions. Only syllable repetition induced significant effects on event-related brain potentials (ERPs) after target onset: a widely distributed positivity in the 200- to 400-ms interval and an anterior positivity in the 400- to 600-ms interval. We interpret these to reflect syllable-size representations at the phonological encoding and phonetic encoding stages. Our results provide the first electrophysiological evidence for the distinct role of syllables in producing Mandarin spoken words, supporting a language specificity hypothesis about the primary phonological units in spoken word production.