RESUMO
The beginnings of words are, in some informal sense, special. This intuition is widely shared, for example, when playing word games. Less apparent is whether the intuition is substantiated empirically and what the underlying organizational principle(s) might be. Here, we answer this seemingly simple question in a quantitatively clear way. Based on arguments about the interplay between lexical storage and speech processing, we examine whether the distribution of information among different speech sounds of words is governed by a critical computational unit for online speech perception and production: syllables. By analyzing lexical databases of twelve languages, we demonstrate that there is a compelling asymmetry between syllable beginnings (onsets) versus ends (codas) in their involvement in distinguishing words stored in the lexicon. In particular, we show that the functional advantage of syllable onset reflects an asymmetrical distribution of lexical informativeness within the syllable unit but not an effect of a global decay of informativeness from the beginning to the end of a word. The converging finding across languages from a range of typological families supports the conjecture that the syllable unit, while being a critical primitive for both speech perception and production, is also a key organizational constraint for lexical storage.
Assuntos
Dissidências e Disputas , Intuição , Humanos , Bases de Dados Factuais , Idioma , FalaRESUMO
A network of left frontal and temporal brain regions supports language processing. This "core" language network stores our knowledge of words and constructions as well as constraints on how those combine to form sentences. However, our linguistic knowledge additionally includes information about phonemes and how they combine to form phonemic clusters, syllables, and words. Are phoneme combinatorics also represented in these language regions? Across five functional magnetic resonance imaging experiments, we investigated the sensitivity of high-level language processing brain regions to sublexical linguistic regularities by examining responses to diverse nonwords-sequences of phonemes that do not constitute real words (e.g. punes, silory, flope). We establish robust responses in the language network to visually (experiment 1a, n = 605) and auditorily (experiments 1b, n = 12, and 1c, n = 13) presented nonwords. In experiment 2 (n = 16), we find stronger responses to nonwords that are more well-formed, i.e. obey the phoneme-combinatorial constraints of English. Finally, in experiment 3 (n = 14), we provide suggestive evidence that the responses in experiments 1 and 2 are not due to the activation of real words that share some phonology with the nonwords. The results suggest that sublexical regularities are stored and processed within the same fronto-temporal network that supports lexical and syntactic processes.
Assuntos
Mapeamento Encefálico , Idioma , Mapeamento Encefálico/métodos , Índia , Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Linguística , Imageamento por Ressonância MagnéticaRESUMO
The growing trend of bilingual education between Chinese and English has contributed to a rise in the number of early bilingual children, who were exposed to L2 prior to formal language instruction of L1. The L2-L1 transfer effect in an L1-dominant environment has been well established. However, the threshold of L2 proficiency at which such transfer manifests remains unclear. This study investigated the behavioral and neural processes involved when manipulating phonemes in an auditory phonological task to uncover the transfer effect in young bilingual children. Sixty-two first graders from elementary schools in Taiwan were recruited in this study (29 Chinese monolinguals, 33 Chinese-English bilinguals). The brain activity was measured using fNIRS (functional near-infrared spectroscopy). Bilingual children showed right lateralization to process Chinese and left lateralization to process English, which supports more on the accommodation effect within the framework of the assimilation-accommodation hypothesis. Also, compared to monolinguals, bilingual children showed more bilateral frontal activation in Chinese, potentially reflecting a mixed influence from L2-L1 transfer effects and increased cognitive load of bilingual exposure. These results elucidate the developmental adjustments in the neural substrates associated with early bilingual exposure in phonological processing, offering valuable insights into the bilingual learning process.
Assuntos
Multilinguismo , Criança , Humanos , Linguística , ChinaRESUMO
BACKGROUND: Word-finding difficulty is prevalent but poorly understood in persons with relapsing-remitting multiple sclerosis (RRMS). OBJECTIVE: The objective was to investigate our hypothesis that phonological processing ability is below expectations and related to word-finding difficulty in patients with RRMS. METHOD: Data were analyzed from patients with RRMS (n = 50) on patient-reported word-finding difficulty (PR-WFD) and objective performance on Wechsler Individual Achievement Test, Fourth Edition (WIAT-4) Phonemic Proficiency (PP; analysis of phonemes within words), Word Reading (WR; proxy of premorbid literacy and verbal ability), and Sentence Repetition (SR; auditory processing of word-level information). RESULTS: Performance (mean (95% confidence interval)) was reliably lower than normative expectations for PP (-0.41 (-0.69, -0.13)) but not for WR (0.02 (-0.21, 0.25)) or SR (0.08 (-0.15, 0.31). Within-subjects performance was worse on PP than on both WR (t(49) = 4.00, p < 0.001, d = 0.47) and SR (t(49) =3.76, p < 0.001, d = 0.54). Worse PR-WFD was specifically related to lower PP (F2,47 = 6.24, p = 0.004, η2 = 0.21); worse PP performance at PR-WFD Often (n = 13; -1.16 (-1.49, -0.83)) than Sometimes (n = 17; -0.14 (-0.68, 0.41)) or Rarely (n = 20; -0.16 (-0.58, 0.27). PR-WFD was unrelated to WR or SR (ps > 0.25). CONCLUSION: Phonological processing was below expectations and specifically linked to word-finding difficulty in RRMS. Findings are consistent with early disease-related cortical changes within the posterior superior temporal/supramarginal region. Results inform our developing model of multiple sclerosis-related word-finding difficulty.
RESUMO
The exploration of naming error patterns in aphasia provides insights into the cognitive processes underlying naming performance. We investigated how semantic and phonological abilities correlate and how they influence naming performance in aphasia. Data from 296 individuals with aphasia, drawn from the Moss Aphasia Psycholinguistics Project Database, were analyzed using a structural equation model. The model incorporated latent variables for semantics and phonology and manifest variables for naming accuracy and error patterns. There was a moderate positive correlation between semantics and phonology after controlling for overall aphasia severity. Both semantic and phonological abilities influenced naming accuracy. Semantic abilities negatively related to semantic, mixed, unrelated errors, and no responses. Interestingly, phonology positively affected semantic errors. Additionally, phonological abilities negatively related to each of phonological and neologism errors. These results highlight the role of semantic and phonological skills on naming performance in aphasia and reveal a relationship between these cognitive processes.
RESUMO
The present longitudinal study investigated the hypothesis that early musical skills (as measured by melodic and rhythmic perception and memory) predict later literacy development via a mediating effect of phonology. We examined 130 French-speaking children, 31 of whom with a familial risk for developmental dyslexia (DD). Their abilities in the three domains were assessed longitudinally with a comprehensive battery of behavioral tests in kindergarten, first grade, and second grade. Using a structural equation modeling approach, we examined potential longitudinal effects from music to literacy via phonology. We then investigated how familial risk for DD may influence these relationships by testing whether atypical music processing is a risk factor for DD. Results showed that children with a familial risk for DD consistently underperformed children without familial risk in music, phonology, and literacy. A small effect of musical ability on literacy via phonology was observed, but may have been induced by differences in stability across domains over time. Furthermore, early musical skills did not add significant predictive power to later literacy difficulties beyond phonological skills and family risk status. These findings are consistent with the idea that certain key auditory skills are shared between music and speech processing, and between DD and congenital amusia. However, they do not support the notion that music perception and memory skills can serve as a reliable early marker of DD, nor as a valuable target for reading remediation. RESEARCH HIGHLIGHTS: Music, phonology, and literacy skills of 130 children, 31 of whom with a familial risk for dyslexia, were examined longitudinally. Children with a familial risk for dyslexia consistently underperformed children without familial risk in musical, phonological, and literacy skills. Structural equation models showed a small effect of musical ability in kindergarten on literacy in second grade, via phonology in first grade. However, early musical skills did not add significant predictive power to later literacy difficulties beyond phonological skills and family risk status.
RESUMO
We examined the reliance on phonological decoding and morpho-orthographic decomposition strategies in developing and skilled readers of French. A lexical decision experiment was conducted where the critical stimuli were four types of nonwords, all derived from the same base word, such as the French word visage (face) in the following examples: (a) pseudo-homophone (PsH) nonwords (e.g., visaje), (b) orthographic controls for PsH nonwords (e.g., visape), (c) pseudo-morphemic (PsM) nonwords (e.g., visageable), and (d) orthographic controls for PsM nonwords (e.g., visagealle, where alle is not a suffix in French). Responses to PsH and PsM nonwords and their controls were studied in three groups of school children (Grades 1, 2, and 5) and one group of skilled adult readers. PsH interference effects (i.e., more errors to PsH nonwords than to the corresponding controls) decreased during reading acquisition to become nonsignificant in skilled readers. Interestingly, the opposite pattern was seen in PsM interference effects (also measured in terms of accuracy), which were already significant in Grade 1 and increased during reading development to reach their maximum in skilled readers. These results point toward opposing learning trajectories in the use of phonological and morphological information when learning to silently read for meaning.
Assuntos
Fonética , Leitura , Adulto , Criança , Humanos , Idioma , Aprendizagem/fisiologiaRESUMO
Learning to spell in an inconsistent orthographic system is a true challenge for primary school children. Previous empirical studies have highlighted three main skills involved in this learning process: phonological skills, morphological skills, and children's sensitivity to graphotactic regularities. However, the literature shows contradictions in the exact nature of the contribution of each skill at different stages of the learning process. So, the aim of our study was to test the contribution of this set of skills in the acquisition of lexical spelling as a function of children's grade level. For this purpose, we assessed these dimensions in a cross-sectional sample of 1101 French-speaking children from Grade 1 to Grade 5. The analyses were conducted using data-driven exploratory network modeling. The results showed (a) a predominant role of phonological skills at the beginning of learning, which tends to decrease with advancing schooling; (b) an increasing contribution of morphological skills from Grade 1 to Grade 5 with a drop in Grade 4, which is the only contribution that continues to increase in Grade 5; and (c) a contribution of the sensitivity to graphotactic regularities that tends to be stable until Grade 4 before decreasing in Grade 5. Our findings show the importance of all three skills in a dynamic process in learning to spell. The implications of these results are discussed in light of the integration of multiple patterns model of learning to spell.
Assuntos
Fonética , Humanos , Estudos Transversais , Masculino , Feminino , Criança , França , Desenvolvimento da Linguagem , Aprendizagem , Instituições Acadêmicas , IdiomaRESUMO
Purpose: The lexical quality (LQ) hypothesis predicts that a skilled reader's lexicon will be inhabited by a range of low- to high-quality items, and the probability of representing a word with high quality varies as a function of person-level, word-level, and item-specific variables. These predictions were tested with spelling accuracy as a gauge of LQ. Method: Item-response based crossed random effects models explored simultaneous contributions of person-level (e.g., participant's decoding skill), word-level (e.g., word's transparency rating), item-specific (e.g., participant's familiarity with specific word), and person-by-word interaction predictors (e.g., decoding by transparency rating interaction) to the spelling of 25 commonly misspelled irregular English words in 61 undergraduate university students (M = 19.4 years, 70.49% female, 39.34% Hispanic, 81.97% White). Results: Substantial variance among individuals in item-level spelling accuracy was accounted for by person-level decoding skill; item-specific familiarity, proportion of schwas correctly represented, and correctly identifying the word from its mispronunciation; and an interaction of transparency rating by general decoding skill. Conclusions: Consistent with the LQ hypothesis, results suggest that one's ability to form a high-quality lexical representation of a given word depends on a complex combination of person-level abilities, word-level characteristics, item-specific experiences, and an interaction between person- and word-level influences.
RESUMO
BACKGROUND: Within cohorts of children with autism spectrum disorder (ASD) there is considerable variation in terms of language ability. In the past, it was believed that children with ASD either had delayed articulation and phonology skills or excelled in those areas compared to other language domains. Very little is known about speech sound ability in relation to language ability and non-verbal ability in Swedish preschool children with ASD. AIM: The current study aimed to describe language variation in a group of 4-6-year-old children with ASD, focusing on in-depth analyses of speech sound error patterns with and without non-phonological language disorder and concomitant non-verbal delays. METHOD & PROCEDURES: We examined and analysed the speech sound skills (including consonant inventory, percentage of correct consonants and speech sound error patterns) in relation to receptive language skills in a sample of preschool children who had screened positive for ASD in a population-based screening at 2.5 years of age. Seventy-three children diagnosed with ASD participated and were divided into subgroups based on their receptive language (i.e., non-phonological language) and non-verbal abilities. OUTCOMES & RESULTS: The subgroup division revealed that 29 children (40%) had language delay/disorder without concurrent non-verbal general cognitive delay (ALD), 27 children (37%) had language delay/disorder with non-verbal general cognitive delay (AGD), and 17 children (23%) had language and non-verbal abilities within the normal range (ALN). Results revealed that children with ALD and children with AGD both had atypical speech sound error patterns significantly more often than the children with ALN. CONCLUSIONS & IMPLICATIONS: This study showed that many children who had screened positive for ASD before age 3 years - with or without non-verbal general cognitive delays - had deficits in language as well as in speech sound ability. However, individual differences were considerable. Our results point to speech sound error patterns as a potential clinical marker for language problems (disorder/delay) in preschool children with ASD. WHAT THIS PAPER ADDS: What is already known on the subject Children with autism spectrum disorder (ASD) have deficits in social communication, restricted interests and repetitive behaviour. They show very considerable variation in both receptive and expressive language abilities. Previously, articulation and phonology were viewed as either delayed in children with ASD or superior compared with other (non-phonological) language domains. What this paper adds to existing knowledge Children with ASD and language disorders also have problems with speech sound error patterns. What are the potential or actual clinical implications of this work? About 75% of children with ASD experience language delays/disorders, as well as speech sound problems, related to speech sound error patterns. Understanding/acknowledging these phonological patterns and their implications can help in the diagnosis and intervention of speech sound disorders in children with ASD. Direct intervention targeting phonology might lead to language gains, but more research is needed.
RESUMO
The tone values of a Tone 4 (T4) syllable are conventionally assumed to change from '51' to '53' when the syllable is followed by another T4 syllable in Mandarin Chinese. Literature focusing on T4 alternation is still inconclusive regarding the contexts for the alternations and whether the phenomenon should be better categorized as tone sandhi (i.e., represented as an abstract phonological rule in mental grammar) or tonal coarticulation (i.e., a natural articulation phenomenon at the phonetic level). The current study probes into these issues by focusing on disyllabic pseudowords, right-branching trisyllabic words as well as unstructured trisyllabic and quadrisyllabic digits. Productions from a total of 148 participants were collected and fundamental frequency (f0) contours, vowel lengths and f0 slopes were included in the analysis. The results from the experiments supported the tonal coarticulation view and showed that the trigger for the alternations was the high-onset tones following T4. Implications to the phonological analysis on tonal alternations in Mandarin Chinese are discussed.
Assuntos
Idioma , Fonética , Acústica da Fala , Humanos , Feminino , Masculino , Taiwan , Medida da Produção da Fala , Adulto , Adulto JovemRESUMO
This study examined the effect of a shape cue (i.e., co-speech gesture) on word depth. We taught 23 preschoolers (M = 3;5 years, SD = 5.82) novel objects with either shape (SHP) or indicator (IND) gestures. SHP gestures mimicked object form, but IND gestures were not semantically related to the object (e.g., an upward-facing palm, extended toward the object). Each object had a unique IND or SHP gesture. Outcome measures reflected richer semantic and phonological learning in the SHP than in the IND condition. In the SHP condition, preschoolers (a) expressed more semantic knowledge, (b) said more sounds in names, and (c) generalized more names to untaught objects. There were also fewer disruptions to prime picture names in the SHP condition; we discuss the benefit of a co-speech shape gesture to capitalize on well-established statistical word learning patterns.
Assuntos
Desenvolvimento da Linguagem , Aprendizagem , Humanos , Semântica , Aprendizagem Verbal , Fala , GestosRESUMO
This contribution presents tools for the assessment of phonological development of Polish-learning children and an initial qualitative evaluation thereof. The tools are consistent with those developed for 16 other languages in a cross-linguistic study of phonological development that is embedded in the framework of constraint-based nonlinear phonology. This theoretical foundation underlies the composition of a Polish word list for elicitation plus a supplementary analysis and intervention planning form (where intervention is warranted). A qualitative pilot study evaluated the tools in terms of adherence to underlying theoretical constructs, coverage of Polish phonology in the developmental context and utility for testing two children, one of whom was characterised by protracted phonological development. Further steps are required to develop the test into a norm-referenced instrument for clinical and research purposes, including quantitative evaluations of the tools' psychometric properties.
RESUMO
Gradient speech change, where speech sound production develops in a broadly step-wise fashion towards the standard adult form, is a well-recognised phenomenon in children developing typical speech, but is much less studied in speakers with developmental speech sound disorders. Instrumental techniques, such as electropalatography (EPG), may be useful for identifying gradient speech change and may supplement phonetic transcription in important ways. This study investigated whether gradient speech change occurred in six participants with cleft palate ± lip undergoing intervention within a usage-based phonology framework (2/6 participants with speech distortions; 4/6 with pattern-based speech substitutions; combined total of 25 speech sounds targeted for intervention). Participants received weekly therapy in a hospital setting and were aged 10-27 years. Gradient speech change with target speech sounds was examined using EPG analysis, which was undertaken after every fifth session of therapy. The presence of gradient change was determined by visually examining EPG palatograms and EPG indices for target speech sounds across successive EPG test points. This study found gradient speech change occurred in 22/25 target sounds over the course of intervention. This gradient change occurred for both speech distortions and pattern-based speech substitutions. The remaining 3/25 target sounds showed categorical change. Usage-based phonology was suggested as a theory with potential for explaining gradient speech change, with both typical and atypical speech, and with speech distortions and pattern-based speech substitutions. This finding adds to other research showing that the objective data provided by instrumental techniques, such as EPG, may be a valuable complement to phonetic transcription.
RESUMO
The left temporo-parietal cortex (TPC) is crucial for phonological decoding, i.e., for learning and retaining sound-letter mappings, and appears hypoactive in dyslexia. Here, we tested the causal contribution of this area for reading in typical readers with transcranial magnetic stimulation (TMS) and explored the reading network's response with fMRI. By investigating the underlying neural correlates of stimulation-induced modulations of the reading network, we can help improve targeted interventions for individuals with dyslexia. 28 typical adult readers overtly read simple and complex words and pseudowords during fMRI after effective and sham TMS over the left TPC. To explore differences in functional activation and effective connectivity within the reading network, we performed univariate and multivariate analyses, as well as dynamic causal modeling. While TMS-induced effects on reading performance and brain activation showed large individual variability, multivariate analyses revealed a shift in activation in the left inferior frontal cortex for pseudoword reading after effective TMS. Furthermore, TMS increased effective connectivity from the left ventral occipito-temporal cortex to the left TPC. In the absence of effects on reading performance, the observed changes in task-related activity and the increase in functional coupling between the two core reading nodes suggest successful short-term compensatory reorganization in the reading network following TMS-induced disruption. This study is the first to explore neurophysiological changes induced by TMS to a core reading node in typical readers while performing an overt reading task. We provide evidence for remote stimulation effects and emphasize the relevance of functional interactions in the reading network.
Assuntos
Mapeamento Encefálico , Dislexia , Adulto , Humanos , Encéfalo/fisiologia , Estimulação Magnética Transcraniana , Lobo Frontal , Imageamento por Ressonância MagnéticaRESUMO
The arcuate fasciculus has been considered a major dorsal fronto-temporal white matter pathway linking frontal language production regions with auditory perception in the superior temporal gyrus, the so-called Wernicke's area. In line with this tradition, both historical and contemporary models of language function have assigned primacy to superior temporal projections of the arcuate fasciculus. However, classical anatomical descriptions and emerging behavioural data are at odds with this assumption. On one hand, fronto-temporal projections to Wernicke's area may not be unique to the arcuate fasciculus. On the other hand, dorsal stream language deficits have been reported also for damage to middle, inferior and basal temporal gyri that may be linked to arcuate disconnection. These findings point to a reappraisal of arcuate projections in the temporal lobe. Here, we review anatomical and functional evidence regarding the temporal cortical terminations of the left arcuate fasciculus by incorporating dissection and tractography findings with stimulation data using cortico-cortical evoked potentials and direct electrical stimulation mapping in awake patients. First, we discuss the fibres of the arcuate fasciculus projecting to the superior temporal gyrus and the functional rostro-caudal gradient in this region where both phonological encoding and auditory-motor transformation may be performed. Caudal regions within the temporoparietal junction may be involved in articulation and associated with temporoparietal projections of the third branch of the superior longitudinal fasciculus, while more rostral regions may support encoding of acoustic phonetic features, supported by arcuate fibres. We then move to examine clinical data showing that multimodal phonological encoding is facilitated by projections of the arcuate fasciculus to superior, but also middle, inferior and basal temporal regions. Hence, we discuss how projections of the arcuate fasciculus may contribute to acoustic (middle-posterior superior and middle temporal gyri), visual (posterior inferior temporal/fusiform gyri comprising the visual word form area) and lexical (anterior-middle inferior temporal/fusiform gyri in the basal temporal language area) information in the temporal lobe to be processed, encoded and translated into a dorsal phonological route to the frontal lobe. Finally, we point out surgical implications for this model in terms of the prediction and avoidance of neurological deficit.
Assuntos
Substância Branca , Lobo Frontal/diagnóstico por imagem , Humanos , Idioma , Rede Nervosa , Vias Neurais , Lobo Temporal/diagnóstico por imagem , Substância Branca/diagnóstico por imagemRESUMO
Teaching phoneme awareness to children at risk for early reading difficulties has been recognized as successful in several studies. In this randomized controlled trial (RCT)-study, we add to this research by optimizing core procedural as well as teaching components in a phonics-directed intervention and extend the RCT reading intervention research into a semi-transparent language context. The aim of the present study was to evaluate the effects of a novel Swedish intensive phonics program. This randomized controlled pre-test and post-test intervention study targeted second-grade students with early reading difficulties. Students were identified by a repeated screening procedure and allocated to intervention (n = 34) and control (n = 34) conditions. A 9-week intensive phonics-based program was administrated one-to-one, by special education teachers in Swedish mainstream elementary schools. Results show an improvement in the intervention group, compared with the controls on all outcome measures. Findings indicate that the supplementary phonics program, delivered with high intensity, can significantly increase word reading skills and reading comprehension in second-grade students with early reading difficulties.
Assuntos
Dislexia , Criança , Humanos , Dislexia/terapia , Suécia , Fonética , Idioma , Leitura , EstudantesRESUMO
Arabic digits (e.g., "6") and number words (e.g., "", "six", " ") are the two main formats in which numbers can be represented. Although phonology plays a crucial role in the semantic accessing of alphabetic words and Chinese characters, whether it is involved in the processing of different numerical notations, which have been shown to be dissociable from characters, is still unknown. Using a parity judgment task, two experiments were performed by manipulating the phonological relationship between a prime and a target. The primes were Tibetan or Chinese characters and the targets were presented either as number words (Experiment 1) or as Arabic digits (Experiment 2). The results revealed that phonology affected semantic access for both number words and Arabic digits. Additionally, semantic access for Tibetan number words was more susceptible to phonological information. The results for Arabic digits followed the same pattern for Tibetan primes. Further, language proficiency also affected the role of phonology in number processing. Participants with low language proficiency relied more on phonological encoding when processing the numbers. The results suggest that phonology is crucial for semantic access of different numerical notations.
Assuntos
Idioma , Semântica , Humanos , Tempo de Reação , JulgamentoRESUMO
Age-related differences in working memory (WM) components were investigated by manipulating the time interval and interference effects between phonological and semantic judgment tasks to identify tasks to best discriminate between younger and older groups. The 96 participants (young = 48; old = 48) prospectively performed two task types of WM, with phonological and semantic judgment tasks, which were administered while varying the three interval conditions: 1-s unfilled (UF), 5-s UF, and 5-s filled (F). The main effect for age was significant in the semantic judgment task but not in the phonological judgment task. The main effect for the interval conditions were significant in both tasks. A 5-s UF condition applied to a semantic judgment task could significantly differentiate the older group from the younger group. Differential effects of time interval manipulation in semantic and phonological processing are involved in WM resources. The older group could be differentiated by varying the task types and interval conditions, indicating that the semantic-related WM burdens may contribute to a superior differential diagnosis of aging-related WM decline.
Assuntos
Julgamento , Memória de Curto Prazo , Humanos , Semântica , EnvelhecimentoRESUMO
This study explored the perceptual assimilation and discrimination of Russian phonemes by three groups of Chinese listeners with differing Russian learning experience. A perceptual assimilation task (PAT) and a perceptual discrimination test (PDT) were conducted to investigate if/how L1-L2 perceptual similarity would vary as a function of increased learning experience, and the development of assimilation-discrimination relations. The PAT was analyzed via assimilation rates, dispersion K' values, goodness ratings and assimilation patterns. Results revealed an intriguing phenomenon that the perceived Mandarin-Russian similarity first increased from naïve listeners to intermediate learners and then decreased slightly in relatively advanced learners. This suggests that L1-L2 perceptual similarity is subject to learning experience and could follow a potential "rise and fall" developmental pattern. The PDT results were mostly in line with the assimilation-discrimination correspondence with more experience bringing out better discriminability in general. Yet the overall sensitivity d' values from the Chinese groups were relatively low, implying acoustic/articulatory effects on L2 discriminability aside from perceptual assimilation. The results were discussed under the frameworks of L2 Perceptual Assimilation Model, Speech Learning Model and L2 Linguistic Perception Model.