Michael D. Tyler

Development of Phonological Constancy Toddlers' Perception of Native- and Jamaican-Accented Words

Efficient word recognition depends on detecting critical phonetic differences among similar-sounding words, or sensitivity to phonological distinctiveness, an ability evident at 19 months of age but unreliable at 14 to 15 months of age. However, little is known about phonological constancy, the equally crucial ability to recognize a words identity across natural phonetic variations, such as those in cross-dialect pronunciation differences. We show that 15- and 19-month-old children recognize familiar words spoken in their native dialect, but that only the older children recognize familiar words in a dissimilar nonnative dialect, providing evidence for emergence of phonological constancy by 19 months. These results are compatible with a perceptual-attunement account of developmental change in early word recognition, but not with statistical-learning or phonological accounts. Thus, the complementary skills of phonological constancy and distinctiveness both appear at around 19 months of age, together providing the child with a fundamental insight that permits rapid vocabulary growth and later reading acquisition.

Learning Nonadjacent Dependencies: No Need for Algebraic-Like Computations

Is it possible to learn the relation between 2 nonadjacent events? M. Pena, L. L. Bonatti, M. Nespor, and J. Mehler (2002) claimed this to be possible, but only in conditions suggesting the involvement of algebraic-like computations. The present article reports simulation studies and experimental data showing that the observations on which Pena et al. grounded their reasoning were flawed by deep methodological inadequacies. When the invalid data are set aside, the available evidence fits exactly with the predictions of a theory relying on ubiquitous associative mechanisms. Because nonadjacent dependencies are frequent in natural language, this reappraisal has far-reaching implications for the current debate on the need for rule-based computations in human adaptation to complex structures.

Vocabulary size matters: The assimilation of second-language Australian English vowels to first-language Japanese vowel categories

Adult second-language (L2) learners’ perception of L2 phonetic segments is influenced by first-language phonological and phonetic properties. It was recently proposed that L2 vocabulary size in adult learners is related to changes in L2 perception (perceptual assimilation model), analogous to the emergence of first-language phonological function (i.e., attunement to the phonological identity of words) associated with the “vocabulary explosion” at 18 months. In a preliminary investigation of the relationship between L2 perception and vocabulary size, Japanese learners of Australian English identified Australian English vowels, provided goodness of fit ratings, and completed a vocabulary size questionnaire. We adopted a “whole-system” approach, allowing learners to apply all native vowel system possibilities to the full L2 vowel system. Learners with a larger L2 vocabulary were more consistent in their vowel assimilation patterns, compatible with the L2 perceptual assimilation model.

Resource Consumption as a Function of Topic Knowledge in Nonnative and Native Comprehension

Previous research suggests that low-level receptive language processes are less developed for nonnative than for native listeners, yet experienced nonnatives seem to comprehend effortlessly in everyday situations. One possible explanation is that experienced nonnatives use topic knowledge to reduce working memory (WM) requirements. Native and experienced nonnatives attended to Bransford and Johnsons (1972) Washing Text while performing a concurrent task, with half of each group given the topic of the passage. Scores on the concurrent task were compared with baseline to index WM consumption. The results showed a relatively greater WM consumption for nonnatives than natives when the topic was unavailable, suggesting that nonnatives rely more than natives on topic knowledge in comprehension. Implications for foreign language learning are discussed.

VOCABULARY SIZE IS ASSOCIATED WITH SECOND-LANGUAGE VOWEL PERCEPTION PERFORMANCE IN ADULT LEARNERS

Improvement in second-language (L2) perception has been posited to occur early in L2 learning when the L2 vocabulary is still small, whereas a large L2 vocabulary curtails perceptual learning (the perceptual assimilation model for SLA [PAM-L2]; Best & Tyler, 2007 ). This proposition is extended by suggesting that early L2 lexical development facilitates the establishment of phonological categories in a manner analogous to children’s first-language (L1) acquisition before as opposed to after the vocabulary spurt. According to this view, L2 speech should be assimilated more consistently to L1 phonological categories and cross-boundary contrasts should be discriminated more accurately by learners with larger L2 vocabularies. To test this proposition, a novel whole-system approach to evaluate perception of L2 vowels in two experiments was applied. In Experiment 1, Japanese learners of Australian English (AusE) with less than 12 weeks of L2 learning in Australia completed labeling and goodness ratings on all AusE vowels, selecting from among all monomoraic and bimoraic Japanese vowels and vowel combinations. They also discriminated four L2 vowel contrasts, representing a range of PAM-L2 contrast types, and completed a L2 vocabulary size assessment. Learners with larger vocabularies had more consistent L2-L1 vowel assimilation and more accurate cross-boundary discrimination than those with smaller vocabularies, supporting the proposition that lexical development assists L2 phonological acquisition. Experiment 2 compared the perception of AusE vowels by Japanese learners after only 4–8 weeks in Australia with their perception after 6–8 months of L2 exposure. The results also supported the predicted positive association between L2 vocabulary size and L2 vowel perception rather than a general prediction of increased exposure duration leading to improved perception.

The edge factor in early word segmentation : utterance-level prosody enables word form extraction by 6-month-olds

Past research has shown that English learners begin segmenting words from speech by 7.5 months of age. However, more recent research has begun to show that, in some situations, infants may exhibit rudimentary segmentation capabilities at an earlier age. Here, we report on four perceptual experiments and a corpus analysis further investigating the initial emergence of segmentation capabilities. In Experiments 1 and 2, 6-month-olds were familiarized with passages containing target words located either utterance medially or at utterance edges. Only those infants familiarized with passages containing target words aligned with utterance edges exhibited evidence of segmentation. In Experiments 3 and 4, 6-month-olds recognized familiarized words when they were presented in a new acoustically distinct voice (male rather than female), but not when they were presented in a phonologically altered manner (missing the initial segment). Finally, we report corpus analyses examining how often different word types occur at utterance boundaries in different registers. Our findings suggest that edge-aligned words likely play a key role in infants’ early segmentation attempts, and also converge with recent reports suggesting that 6-month-olds’ have already started building a rudimentary lexicon.

Language context elicits native-like stop voicing in early bilinguals’ productions in both L1 and L2

The way that bilinguals produce phones in each of their languages provides a window into the nature of the bilingual phonological space. For stop consonants, if early sequential bilinguals, whose languages differ in voice onset time (VOT) distinctions, produce native-like VOTs in each of their languages, it would imply that they have developed separate first and second language phones, that is, language-specific phonetic realisations for stop-voicing distinctions. Given the ambiguous phonological status of Greek voiced stops, which has been debated but not investigated experimentally, Greek-English bilinguals can offer a unique perspective on this issue. We first recorded the speech of Greek and Australian-English monolinguals to observe native VOTs in each language for /p, t, b, d/ in word-initial and word-medial (post-vocalic and post-nasal) positions. We then recorded fluent, early Greek-Australian-English bilinguals in either a Greek or English language context; all communication occurred in only one language. The bilinguals in the Greek context were indistinguishable from the Greek monolinguals, whereas the bilinguals in the English context matched the VOTs of the Australian-English monolinguals in initial position, but showed some modest differences from them in the phonetically more complex medial positions. We interpret these results as evidence that bilingual speakers possess phonetic categories for voiced versus voiceless stops that are specific to each language, but are influenced by positional context differently in their second than in their first language.

Perceptual assimilation and discrimination of non-native vowel contrasts.

Research on language-specific tuning in speech perception has focused mainly on consonants, while that on non-native vowel perception has failed to address whether the same principles apply. Therefore, non-native vowel perception was investigated here in light of relevant theoretical models: the Perceptual Assimilation Model (PAM) and the Natural Referent Vowel (NRV) framework. American-English speakers completed discrimination and native language assimilation (categorization and goodness rating) tests on six nonnative vowel contrasts. Discrimination was consistent with PAM assimilation types, but asymmetries predicted by NRV were only observed for single-category assimilations, suggesting that perceptual assimilation might modulate the effects of vowel peripherality on non-native vowel perception.

Parameters in Television Captioning for Deaf and Hard-of-Hearing Adults: Effects of Caption Rate Versus Text Reduction on Comprehension

Caption rate and text reduction are factors that appear to affect the comprehension of captions by people who are deaf or hard of hearing. These 2 factors are confounded in everyday captioning; rate (in words per minute) is slowed by text reduction. In this study, caption rate and text reduction were manipulated independently in 2 experiments to assess any differential effects and possible benefits for comprehension by deaf and hard-of-hearing adults. Volunteers for the study included adults with a range of reading levels, self-reported hearing status, and different communication and language preferences. Results indicate that caption rate (at 130, 180, 230 words per minute) and text reduction (at 84%, 92%, and 100% original text) have different effects for different adult users, depending on hearing status, age, and reading level. In particular, reading level emerges as a dominant factor: more proficient readers show better comprehension than poor readers and are better able to benefit from caption rate and, to some extent, text reduction modifications.

Measuring Relative Cue Strength as a Means of Validating an Inventory of Expert Offender Profiling Cues

Cues have been identified as important precursors to successful diagnoses among expert practitioners. However, current approaches to the identification of expert cues typically rely on subjective methods, making the validity of cues difficult to establish. The present research examined the utility of a Paired-Concept Association Task (P-CAT) as a basis for discriminating expert and novice cue activation in the context of offender profiling. Three studies are reported: 1A employed a cognitive interview for the acquisition of cue-based concepts used by experts and novices; 1B presented pairs of concepts as part of the P-CAT, which recorded response latency; and, 1C employed a survey to further gauge participants’ perceptions of the concepts. The results revealed differences between experts and novices in the cue-based associations activated, and in the response latencies associated with the P-CAT, across expertise. The P-CAT accurately discriminated expert from novice cue activation and consequently offers a new method for objectively validating expert cue use.