A Shift in the Direction of the Production Effect in Children Aged 2-6 Years.

Research has found mixed evidence for the production effect in childhood. Some studies have found a positive effect of production on word recognition and recall, while others have found the reverse. This paper takes a developmental approach to investigate the production effect. Children aged 2-6 years (n = 150) from a predominantly white population in Ottawa, Canada were trained on familiar words which were either seen, heard or produced, followed by a recall task. Results showed a developmental shift: younger participants showed a reverse production effect, recalling more words that were heard during training, while older children showed the typical production effect, recalling more produced words. The effect of production on recall is not unidirectional and varies by age.

Discrimination of four Canadian-French vowels by native Canadian-English listeners.

Discrimination of Canadian French /y/, /u/, /ɑ/, and /e/ by native Canadian-English listeners was investigated to determine if patterns found in standard varieties of French (as explained by the Perceptual Assimilation Model) could be replicated in Canadian French. Front-rounded /y/ paired with /u/ was the focus of investigation, as well as other (control) pairs. It was found that /y/-/u/ was the most difficult to discriminate as compared to other pairs, but that listeners were sensitive to the contrast, which replicates previous findings in European French. Results are explained as a mix of instances of single-category and category-goodness assimilation patterns.

Monolingual and bilingual children's processing of coarticulation cues during spoken word recognition.

Bilingual children cope with a significant amount of phonetic variability when processing speech, and must learn to weigh phonetic cues differently depending on the cues' respective roles in their two languages. For example, vowel nasalization is coarticulatory and contrastive in French, but coarticulatory-only in English. In this study, we extended an investigation of the processing of coarticulation in two- to three-year-old English monolingual children (Zamuner, Moore & Desmeules-Trudel, 2016) to a group of four- to six-year-old English monolingual children and age-matched English-French bilingual children. Using eye tracking, we found that older monolingual children and age-matched bilingual children showed more sensitivity to coarticulation cues than the younger children. Moreover, when comparing the older monolinguals and bilinguals, we found no statistical differences between the two groups. These results offer support for the specification of coarticulation in word representations, and indicate that, in some cases, bilingual children possess language processing skills similar to monolinguals.

Toddlers' sensitivity to within-word coarticulation during spoken word recognition: Developmental differences in lexical competition.

To understand speech, listeners need to be able to decode the speech stream into meaningful units. However, coarticulation causes phonemes to differ based on their context. Because coarticulation is an ever-present component of the speech stream, it follows that listeners may exploit this source of information for cues to the identity of the words being spoken. This research investigates the development of listeners' sensitivity to coarticulation cues below the level of the phoneme in spoken word recognition. Using a looking-while-listening paradigm, adults and 2- and 3-year-old children were tested on coarticulation cues that either matched or mismatched the target. Both adults and children predicted upcoming phonemes based on anticipatory coarticulation to make decisions about word identity. The overall results demonstrate that coarticulation cues are a fundamental component of children's spoken word recognition system. However, children did not show the same resolution as adults of the mismatching coarticulation cues and competitor inhibition, indicating that children's processing systems are still developing.

Spoken word recognition in a second language: The importance of phonetic details.

Spoken word recognition depends on variations in fine-grained phonetics as listeners decode speech. However, many models of second language (L2) speech perception focus on units such as isolated syllables, and not on words. In two eye-tracking experiments, we investigated how fine-grained phonetic details (i.e. duration of nasalization on contrastive and coarticulatory nasalized vowels in Canadian French) influenced spoken word recognition in an L2, as compared to a group of native (L1) listeners. Results from L2 listeners (English-native speakers) indicated that fine-grained phonetics impacted the recognition of words, i.e. they were able to use nasalization duration variability in a way similar to L1-French listeners, providing evidence that lexical representations can be highly specified in an L2. Specifically, L2 listeners were able to distinguish minimal word pairs (differentiated by the presence of phonological vowel nasalization in French) and were able to use variability in a way approximating L1-French listeners. Furthermore, the robustness of the French "nasal vowel" category in L2 listeners depended on age of exposure. Early bilinguals displayed greater sensitivity to some ambiguity in the stimuli than late bilinguals, suggesting that early bilinguals had greater sensitivity to small variations in the signal and thus better knowledge of the phonetic cue associated with phonological vowel nasalization in French, similarly to L1 listeners.

Learning unfamiliar words and perceiving non-native vowels in a second language: Insights from eye tracking.

One of the challenges in second-language learning is learning unfamiliar word forms, especially when this involves novel phoneme contrasts. The present study examines how real-time processing of newly-learned words and phonemes in a second language is impacted by the structure of learning (discrimination training) and whether asking participants to complete the same task after a 16-21 h delay favours subsequent word recognition. Specifically, using a visual world eye tracking paradigm, we assessed how English listeners processed newly-learned words containing non-native French front-rounded [y] compared to native-sounding vowels, both immediately after training and the following day. Some learners were forced to discriminate between vowels that are perceptually similar for English listeners, [y]-[u], while others were not. We found significantly better word-level processing on a variety of indices after an overnight delay. We also found that training [y] words paired with [u] words (vs. [y]-Control pairs) led to a greater decrease in reaction times during the word recognition task over the two testing sessions. Discrimination training using perceptually similar sounds had facilitative effects on second language word learning with novel phonemic information, and real-time processing measures such as eyetracking provided valuable insights into how individuals learn words and phonemes in a second language.

Gradient and categorical patterns of spoken-word recognition and processing of phonetic details.

The speech signal is inherently rich, and this reflects complexities of speech articulation. During spoken-word recognition, listeners must process time-dependent perceptual cues, and the role that these cues play varies depending on the phonological status of the sounds across languages. For example, Canadian French has both phonologically nasal vowels (i.e., contrastive) and coarticulatorily nasalized vowels, as opposed to English, which only has coarticulatorily nasalized vowels. We investigated how vowel nasalization duration, a time-dependent phonetic cue to the French nasal contrast, affects spoken-word recognition. Using eye tracking in two visual world paradigm experiments, the results show that fine-grained phonetic information is important for lexical recognition, and that lexical access is dependent on small variations in the signal. The results also show gradient interpretation of ambiguous vowel nasalization despite the phonemic distinction between phonological nasal vowels and coarticulatorily nasalized vowels in Canadian French. Gradience was found when words were ambiguous, and interpretation was more categorical when words were unambiguous. These results support the hypothesis of gradient interpretation of phonetic cues for ambiguously produced stimuli and the storage of coarticulatory information in phono-lexical representations for a language that has a phonological contrast for nasality (i.e., French).

Correction to: Gradient and categorical patterns of spoken-word recognition and processing of phonetic details.

The Publisher regrets that, due to a typesetting mistake, it has now become necessary to make the following corrections: All phonetic transcriptions (between square brackets and slashes) should be corrected and displayed as follows, in the same font.