In this paper we investigated the real-time processing of epistemic modals in five-year-olds. In a simple reasoning scenario, we monitored children's eye-movements while processing a sentence with modal expressions of different force (might/must). Children were also asked to judge the truth-value of the target sentences at the end of the reasoning task. Consistent with previous findings (Noveck, 2001), we found that children's behavioural responses were much less accurate compared to adults. Their eye-movements, however, revealed that children did not treat the two modal expressions alike. As soon as a modal expression was presented, children and adults showed a similar fixation pattern that varied as a function of the modal expression they heard. It is only at the very end of the sentence that children's fixations diverged from the adult ones. We discuss these findings in relation to the proposal that children narrow down the set of possible outcomes in undetermined reasoning scenarios and endorse only one possibility among several (Acredolo & Horobin, 1987, Ozturk & Papafragou, 2015).

We suggest that preschoolers’ frequent obliviousness to the risks and opportunities of deception comes from a trusting stance supporting verbal communication. Three studies (N = 125) confirm this hypothesis. Three-year-olds can hide information from others (Study 1) and they can lie (Study 2) in simple settings. Yet when one introduces the possibility of informing others in the very same settings, three-year-olds tend to be honest (Studies 1 and 2). Similarly, four-year-olds, though capable of treating assertions as false, trust deceptive informants (Study 3). We suggest that children's reduced sensitivity to the opportunities of lying, and to the risks of being lied to might help explain their difficulties on standard false belief tasks.

The goal of this study was to investigate non-adjacent consonant sequence patterns in target words during the first-word period in infants learning American English. In the spontaneous speech of eighteen participants, target words with a Consonant–Vowel–Consonant (C1VC2) shape were analyzed. Target words were grouped into nine types, categorized by place of articulation (labial, coronal, dorsal) of initial and final consonants (e.g. mom, labial–labial; mat, labial–coronal; dog, coronal–dorsal). The results indicated that some consonant sequences occurred much more frequently than others in early target words. The two most frequent types were coronal–coronal (e.g. dad) and labial–coronal (e.g. mat). The least frequent type was dorsal–dorsal (e.g. cake). These patterns are consistent with phonotactic characteristics of English and infants' production capacities reported in previous studies. This study demonstrates that infants' expressive vocabularies reflect both ambient language characteristics and their own production capacities, at least for consonant sequences in C1VC2 word forms.

Both touch and speech independently have been shown to play an important role in infant development. However, little is known about how they may be combined in the input to the child. We examined the use of touch and speech together by having mothers read their 5-month-olds books about body parts and animals. Results suggest that speech+touch multimodal events are characterized by more exaggerated touch and speech cues. Further, our results suggest that maternal touches are aligned with speech and that mothers tend to touch their infants in locations that are congruent with names of body parts. Thus, our results suggest that tactile cues could potentially aid both infant word segmentation and word learning.

Onomatopoeia are frequently identified amongst infants’ earliest words (Menn & Vihman, 2011), yet few authors have considered why this might be, and even fewer have explored this phenomenon empirically. Here we analyze mothers’ production of onomatopoeia in infant-directed speech (IDS) to provide an input-based perspective on these forms. Twelve mothers were recorded interacting with their 8-month-olds; onomatopoeic words (e.g. quack) were compared acoustically with their corresponding conventional words (duck). Onomatopoeia were more salient than conventional words across all features measured: mean pitch, pitch range, word duration, repetition, and pause length. Furthermore, a systematic pattern was observed in the production of onomatopoeia, suggesting a conventionalized approach to mothers’ production of these words in IDS.

There have been many studies examining the differences between infant-directed speech (IDS) and adult-directed speech (ADS). However, investigations asking whether mothers clarify vowel articulation in IDS have reached equivocal findings. Moreover, it is unclear whether maternal speech clarification has any effect on a child's developing language skills. This study examined vowel clarification in mothers’ IDS at 0;10–11, 1;6, and 2;0, as compared to their vowel production in ADS. Relationships between vowel space, vowel duration, and vowel variability and child language outcomes at two years were also explored. Results show that vowel space and vowel duration tended to be greater in IDS than in ADS, and that one measure of vowel clarity, a mother's vowel space at 1;6, was significantly related to receptive as well as expressive child language outcomes at two years of age.

Recent research indicates that infants can learn novel words equally well through addressed speech as through overhearing two adult experimenters. The current study examined to which extent six-year-old children learn from overhearing opportunities in regular kindergarten classroom practices. Fifty-three children (M age = 5;6) were exposed to a story with twelve novel words in three different conditions. In the Addressed condition, children were directly addressed to listen to the story. In the Overhearing Classroom, the children were assigned to a task within earshot of the children of the Addressed condition. In the Overhearing Two Adults condition, the experimenter told the story to another adult. The results showed that the Addressees learned equally well as the Overhearers of Two Adults. However, in the Overhearing Classroom condition children learned significantly fewer words compared to the two other conditions. Different hypotheses are offered to explain the relative success of overhearing two adults compared to overhearing classroom interactions.

This study focuses on the relationship between content elements and mental-state language in narratives from twenty-seven children with autism (ASD), twelve children with language impairment (LI), and thirty typically developing children (TD). The groups did not differ on chronological age (10;6–14;0) and non-verbal cognitive skills, and the groups with ASD and TD did not differ on language measures. The children with ASD and LI had fewer content elements of the storyline than the TD children. Compared with the TD children, the children with ASD used fewer subordinate clauses about the characters’ thoughts, and preferred talking about mental states as reported speech, especially in the form of direct speech. The children with LI did not differ from the TD children on these measures. The results are discussed in the context of difficulties with socio-cognition in children with ASD and of language difficulties in children with LI.

This study investigates the contributions of semantic, phonological, and orthographic factors to morphological awareness of 413 Chinese-speaking students in Grades 2, 4, and 6, and its relationship with reading comprehension. Participants were orally presented with pairs of bimorphemic compounds and asked to judge whether the first morphemes of the words shared a meaning. Morpheme identity (same or different), whole-word semantic relatedness (high or low), orthography (same or different), and phonology (same or different) were manipulated. By Grade 6, children were able to focus on meaning similarities across morphemes while ignoring the distraction of form, but they remained influenced by whole-word semantic relatedness. Children's ability to overcome the distraction of phonology consistently improved with age, but did not reach ceiling, whereas the parallel ability for orthography reached ceiling at Grade 6. Morphological judgment performance was a significant unique predictor of reading comprehension when character naming and vocabulary knowledge were accounted for.

This study investigated the relation between lexical development and the production of prosodic prominence in disyllabic babble and words. Monthly recordings from nine typically developing Belgian-Dutch-speaking infants were analyzed from the onset of babbling until a cumulative vocabulary of 200 words was reached. The differentiation between the two syllables of isolated disyllabic utterances was computed for f0, intensity, and duration measurements. Results showed that the ambient trochaic pattern emerged in babble, but became enhanced in words. Words showed more prosodic differentiation in terms of f0 and intensity and a more even duration ratio. Age or vocabulary size did not predict the expansion of f0 or intensity in words, whereas vocabulary size was related to the production of more even-timed syllables. The findings are discussed in terms of lexicalist accounts of phonetic development and a potential phonetic highlighting function of first words.

Lexical stress is the contrast between strong and weak syllables within words. Ballard et al. (2012) examined the amount of stress contrastivity across adjacent syllables in word productions of typically developing three- to seven-year-olds and adults. Here, eight- to eleven-year-olds are compared with the adults from Ballard et al. using acoustic measurements of relative contrast in duration, peak intensity, and peak fundamental frequency of the vowels within the initial two syllables of each word. While eight- to eleven-year-olds are closer to adult-like stress contrastivity than three- to seven-year-olds, they are not yet adult-like in terms of the intensity contrast for words beginning with a weak syllable.