Journal of Child Language最新文献

Limited studies have examined demographic differences in children's vocabulary in longitudinal samples, while there are questions regarding the duration, direction, and magnitude of these effects across development. In this longitudinal study, we included over 400 Dutch children. Caregivers filled out N-CDIs when children were 9-11 months (measuring word comprehension, word production, and gestures) and around 2-5 years of age (measuring word production). At 2-5 years, we also administered a receptive vocabulary task in the lab. We examined demographic effects on vocabulary size across infancy and toddlerhood. We found a disadvantage for males in infants' gestures and toddlers' vocabulary production. We found a negative effect of maternal education on infants' caregiver-reported vocabulary, but a positive effect on toddlers' lab-administered receptive vocabulary. Lastly, we found a negative effect of multilingualism - but only for the lab-administered task. Examining predictors in large, longitudinal samples ensures their robustness and generalisability across development.

We assess the feasibility of conducting web-based eye-tracking experiments with children using two methods of webcam-based eye-tracking: automatic gaze estimation with the WebGazer.js algorithm and hand annotation of gaze direction from recorded webcam videos. Experiment 1 directly compares the two methods in a visual-world language task with five to six year-old children. Experiment 2 more precisely investigates WebGazer.js' spatiotemporal resolution with four to twelve year-old children in a visual-fixation task. We find that it is possible to conduct web-based eye-tracking experiments with children in both supervised (Experiment 1) and unsupervised (Experiment 2) settings - however, the webcam eye-tracking methods differ in their sensitivity and accuracy. Webcam video annotation is well-suited to detecting fine-grained looking effects relevant to child language researchers. In contrast, WebGazer.js gaze estimates appear noisier and less temporally precise. We discuss the advantages and disadvantages of each method and provide recommendations for researchers conducting child eye-tracking studies online.

This study mapped the trajectory of developing derivational morphological knowledge in Hebrew monolingual and Russian-Hebrew bilingual children. We investigated 2^nd and 4^th graders, using a two-by-two structure along the dimensions of modality (comprehension, production) and type of word (real-word, pseudo-word). Performance in the morphological analogies comprehension tasks improved with grade, and monolingual and bilingual children performed equally well. A different pattern was evident in production tasks. In real-word production, monolingual children were more accurate than bilingual children, but this group difference narrowed with age. In pseudo-word production, monolingual children used more morphological elements than bilingual children, and there was also a tendency towards group differences narrowing with age. Detailed error analyses across all tasks revealed that monolingual children recruited more morphological elements than bilingual children. We present implications for assessment of morphological knowledge, and suggest that morphological intervention is a promising avenue for promoting bilingual children's success.

The purpose of the current study was to revisit a controversial topic: whether frequencies of phonological consonant and vowel classes differ in speech directed to children and to adults. In addition, the current study investigated whether the frequency of phonological consonant and vowel classes changes with children's increasing chronological and/or developmental age. This study analyzed speech input from 44 adults to four different age groups of listeners (i.e., three groups of children at 6, 18, and 36 months of age and one group of adult listeners) in terms of frequency of occurrence of consonant and vowel classes. Results revealed that consonant stop, nasal, fricative and glide manner classes as well as all four consonant place classes were significantly different in speech directed to the four different age groups. A perspective is discussed to better understand the nature of frequency input of phonological sound classes.

Young children today are exposed to masks on a regular basis. However, there is limited empirical evidence on how masks may affect word learning. The study explored the effect of masks on infants' abilities to fast-map and generalize new words. Seventy-two Chinese infants (43 males, M_age = 18.26 months) were taught two novel word-object pairs by a speaker with or without a mask. They then heard the words and had to visually identify the correct objects and also generalize words to a different speaker and objects from the same category. Eye-tracking results indicate that infants looked longer at the target regardless of whether a speaker wore a mask. They also looked longer at the speaker's eyes than at the mouth only when words were taught through a mask. Thus, fast-mapping and generalization occur in both masked and not masked conditions as infants can flexibly access different visual cues during word-learning.

Indirect answers are a common type of non-literal language that do not provide an explicit "yes" or "no" to a question (e.g., "I have to work late" indirectly answered "Are you going to the party?" with a negative response). In the current study, we examined the developmental trajectory of comprehension of indirect answers among 5- to 10-year-old children with typical development. Forty-eight children, 23 boys and 25 girls, between the ages of 5 years; 0 months and 10 years; 11 months (M = 8;2, SD = 19.77 months) completed an experimental task to judge whether a verbally presented indirect answer meant yes or no (Comprehension Task) and then explain their choice (Explanation Task). Responses were scored for accuracy and coded for error analysis. On the Comprehension Task, the 5- to 8-year-olds performed with approximately 85% accuracy, while the 9- and 10-year-olds achieved 95% accuracy. On the Explanation Task, the cross-sectional trajectory revealed three stages: the 5- and 6-year-olds adequately explained indirect answers 32% of the time, the 7- and 8-year-olds performed significantly higher at 55%, and the 9- and 10-year-olds made significant gains than the younger children at 66%. Error analysis revealed that when children fail to interpret speaker intentions appropriately, they repeat the speaker's utterance or provide an insufficient explanation 80% of the time. Other responses, such as those irrelevant to the context, indicating "I don't know" or no response, or that were made-up interpretations each accounted for 2%-10% of total inadequate explanations. Study findings indicate discrepancies between task performances and offer two separate sets of baseline data for future comparisons that investigate comprehension or explanation of indirect answers by children with different cultural and linguistic backgrounds and by those with varying cognitive and language profiles.

The feature [+spread glottis] ([+s.g.]) denotes that a speech sound is produced with a wide glottal aperture with audible voiceless airflow. Icelandic is unusual in the degree to which [+spread glottis] is involved in the phonology: in /h/, pre-aspirated and post-aspirated stops, voiceless fricatives and voiceless sonorants. The ubiquitousness of the feature could potentially affect the rate and process of its acquisition. This paper investigates the development of [+s.g.] in Icelandic, both in general and in a range of contexts, in a cross-sectional study of 433 typically developing Icelandic-speaking children aged two to seven years. As a feature, [+s.g.] is acquired early in Icelandic, although specific sound classes lag behind due to other output constraints. Children reach mastery of [+s.g.] by age three except in word-initial post-aspirated stops and voiceless nasals. Findings are interpreted in light of the literature on the feature and its development.

In this study, we report an extensive investigation of the structural language and acoustical specificities of the spontaneous speech of ten three- to five-year-old verbal autistic children. The autistic children were compared to a group of ten typically developing children matched pairwise on chronological age, nonverbal IQ and socioeconomic status, and groupwise on verbal IQ and gender on various measures of structural language (phonetic inventory, lexical diversity and morpho-syntactic complexity) and a series of acoustical measures of speech (mean and range fundamental frequency, a formant dispersion index, syllable duration, jitter and shimmer). Results showed that, overall, the structure and acoustics of the verbal autistic children's speech were highly similar to those of the TD children. Few remaining atypicalities in the speech of autistic children lay in a restricted use of different vocabulary items, a somewhat diminished morpho-syntactic complexity, and a slightly exaggerated syllable duration.

This study investigated links between the development of children's understanding of ironic comments and their metapragmatic knowledge. Forty-six 8-year-olds completed the short version of the Irony Comprehension Task, during which they were presented with ironic comments in three stories and asked to provide reasons for why the speaker in a story uttered an ironic comment. We coded their responses and compared the results to similar data collected previously with 5-year-olds. Results showed that compared to younger children, 8-year-olds frequently refer to interlocutors' emotions, intentions, and to metapragmatics. These results support the view that comprehension of verbal irony is an emerging skill in children.