In a preferential looking paradigm, we studied how children's looking behavior and pupillary response were modulated by the degree of phonological mismatch between the correct label of a target referent and its manipulated form. We manipulated degree of mismatch by introducing one or more featural changes to the target label. Both looking behavior and pupillary response were sensitive to degree of mismatch, corroborating previous studies that found differential responses in one or the other measure. Using time-course analyses, we present for the first time results demonstrating full separability among conditions (detecting difference not only between one vs. more, but also between two and three featural changes). Furthermore, the correct labels and small featural changes were associated with stable target preference, while large featural changes were associated with oscillating looking behavior, suggesting significant shifts in looking preference over time. These findings further support and extend the notion that early words are represented in great detail, containing subphonemic information.

Weak syllables in Germanic and Romance languages have been reported to be challenging for young children, with syllable omission and/or incomplete reduction persisting till age five. In Mandarin Chinese, neutral tone (T0) involves a weak syllable with varied pitch realizations across (preceding) tonal contexts and short duration. The present study examined how and when T0 was acquired by 108 Beijing Mandarin-speaking children (3–5 years) relative to 33 adult controls. Lexicalized (familiar) and non-lexicalized (unfamiliar) T0 words were elicited in different preceding tonal contexts. Unlike previous reports, the present study revealed that children as young as three years have already developed a phonological category for T0, exhibiting contextually conditioned tonal realizations of T0 for both familiar and unfamiliar items. However, mastery of adult-like pitch and duration implementation of T0 is a protracted process not completed until age five. The implications for the acquisition of weak syllables more generally are discussed.

A battery of standardized language tests and control measures was administered to three groups of at-risk language learners – internationally adopted children, deaf children with cochlear implants, and children with specific language impairment – and to groups of second-language learners and typically developing monolingual children. All children were acquiring French, were matched on age, gender, and socioeconomic status, and were between age 5;0 and 7;3 at the time of testing. Differences between the at-risk and not-at-risk groups were evident in all domains of language testing. The children with SLI or CIs scored significantly lower than the IA children and all three at-risk groups scored lower than the monolingual group; the L2 and IA groups scored similarly. The results suggest that children with limited access to, or ability to process, early language input are at greater risk than children with delayed input to an additional language but otherwise typical or relatively typical early input.

This study investigated whether cross-linguistic differences affect semantic prediction. We assessed this by looking at two languages, Dutch and Turkish, that differ in word order and thus vary in how words come together to create sentence meaning. In an eye-tracking task, Dutch and Turkish four-year-olds (N = 40), five-year-olds (N = 58), and adults (N = 40) were presented with a visual display containing two familiar objects (e.g., a cake and a tree). Participants heard semantically constraining (e.g., “The boy eats the big cake”) or neutral sentences (e.g., “The boy sees the big cake”) in their native language. The Dutch data revealed a prediction effect for children and adults; however, it was larger for the adults. The Turkish data revealed no prediction effect for the children but only for the adults. These findings reveal that experience with word order structures and/or automatization of language processing routines may lead to timecourse differences in semantic prediction.

Infants begin to understand some of the meanings of the adjective good at around thirteen months, but it is not clear when they start to map it to concepts in the moral domain. We investigated infants’ and toddlers’ knowledge of good in the domains of help and fairness. Participants at 20 and 30 months were shown computer animations involving helpful and hindering agents, or agents who performed fair or unfair distributions, and were asked to “pick the good one”. Toddlers at 30 months took good as referring to helping, but not to the fair agents. However, when asked “to pick one”, they choose the fair distributor. These findings suggest that by 30 months toddlers have started to map good to some socio-moral features, such as a helping disposition, but not to fairness in distributive actions.

The perception and production of emotional and linguistic (focus) prosody were compared in children with cochlear implants (CI) and normally hearing (NH) peers. Thirteen CI and thirteen hearing-age-matched school-aged NH children were tested, as baseline, on non-verbal emotion understanding, non-word repetition, and stimulus identification and naming. Main tests were verbal emotion discrimination, verbal focus position discrimination, acted emotion production, and focus production. Productions were evaluated by NH adult Dutch listeners. All scores between groups were comparable, except a lower score for the CI group for non-word repetition. Emotional prosody perception and production scores correlated weakly for CI children but were uncorrelated for NH children. In general, hearing age weakly predicted emotion production but not perception. Non-verbal emotional (but not linguistic) understanding predicted CI children's (but not controls’) emotion perception and production. In conclusion, increasing time in sound might facilitate vocal emotional expression, possibly requiring independently maturing emotion perception skills.

In this exploratory study, we examined stress contrastivity within real word productions elicited via picture naming in 20 children with autism spectrum disorders (ASD) and 20 typical peers group-wise matched on age and vocabulary. Targets had a dominant pattern of lexical stress beginning with a strong–weak pattern (SW: ‘caterpillar’, ‘butterfly’) or a non-dominant pattern of lexical stress beginning with a weak–strong pattern (WS: ‘tomato’, ‘potato’). Children produced each target twice (n = 320 productions). Acoustic measures were made for the duration, fundamental frequency, and intensity of the first two vowels for each word production. For vowel duration and fundamental frequency, children with ASD and typical peers produced a similar magnitude of stress contrastivity for SW and WS words. However, there was a significant group difference in the way contrastivity in intensity was realised for WS words whereby children with ASD produced less stress contrastivity than typical peers. Bayesian analyses were in line with our interpretation of our frequentist analyses.

Many studies have addressed the effect of neighborhood density (phonological similarity among words) on word learning in quiet listening conditions. We explored how noise influences the effect of neighborhood density on children's word learning. One-hundred-and-two preschoolers learned nonwords varied in neighborhood density in one of four listening conditions: quiet, +15 dB signal-to-noise ratio (SNR), +6 dB SNR, and 0 dB SNR. Results showed that a high-density advantage for children under quiet listening condition was significantly reduced as noise increased. This finding implies an adverse impact of noise on long-term outcomes of word learning.

Previous research in child language shows that many aspects of language acquisition are frequency-linked. This study tests whether input or usage frequency predicts the order of acquisition and accuracy of a bilingual Greek–English child's English possessives. The child was followed longitudinally from age 2;6 to 3;11. Order of acquisition was comparable to that of same-aged monolingual children. The child's usage frequency and order of acquisition were highly correlated with input frequency, while her accuracy was not. We argue that the child's already-acquired Greek possessives facilitated acquisition of English possessives, even though the child's English input and usage frequencies were lower than in monolingual English children.

In lexical development, the specificity of phonological representations is important. The ability to build phonologically specific lexical representations predicts the number of words a child knows (vocabulary breadth), but it is not clear if it also fosters how well words are known (vocabulary depth). Sixty-six children were studied in kindergarten (age 5;7) and first grade (age 6;8). The predictive value of the ability to learn phonologically similar new words, phoneme discrimination ability, and phonological awareness on vocabulary breadth and depth were assessed using hierarchical regression. Word learning explained unique variance in kindergarten and first-grade vocabulary depth, over the other phonological factors. It did not explain unique variance in vocabulary breadth. Furthermore, even after controlling for kindergarten vocabulary breadth, kindergarten word learning still explained unique variance in first-grade vocabulary depth. Skill in learning phonologically similar words appears to predict knowledge children have about what words mean.