Purpose: This study evaluates the impact of temporal synchrony between maternal touch and speech on children's early language development. It investigates whether the proportion of word-touch co-occurrence, overlap, and alignment precision in maternal input influences language acquisition, hypothesizing that such synchrony boosts infants'…

Developmental difference is a common characteristic of autism spectrum disorder (ASD) with unclear sex differences. The current study included 610 children with ASD, aged between 2 and 7 years, with completed language profiles. We used a nonparametric item response theory model called Mokken scale analysis to examine the order of acquisition of…

Joint attention and imitation are thought to facilitate a developmental cascade of language and social communication skills. Delays in developing these skills may affect the quality of children's social interactions and subsequent language development. We examined how responding to joint attention and object imitation skills predicted rate of…

A basic question about bilingual development is how the acquisition of one language affects the acquisition of the other. Previous findings are few and mixed. The present study addressed this question with longitudinal data on the dual-language vocabulary growth of 149 US-born children from Spanish-speaking immigrant families, who were followed…

Purpose: A rich body of evidence has illuminated the importance of caregivers' use of prosody in facilitating young children's language development. Although caregiver-child shared reading has been repeatedly linked to children's language skills, caregiver prosody during shared reading interactions (i.e., oral reading expressiveness) has been…

Parents assessed the development of 12,081 two- to six-year-old children with Autism Spectrum Disorder (ASD) quarterly for three years on five subscales: combinatorial receptive language, expressive language, sociability, sensory awareness, and health. Longer duration of time spent with an adult actively involved in the same activity (termed here…

Vocabulary size is a crucial early indicator of language development, for both monolingual and bilingual children. Assessing vocabulary in bilingual children is complex because they learn words in two languages, and there remains significant controversy about how to best measure their vocabulary size, especially in relation to monolinguals. This…

Purpose: Prior work has found that "late talkers" (LTs) as a group continue to demonstrate lower language and reading outcomes compared to their typically developing (TD) peers even into young adulthood. Others identified that children diagnosed with developmental language disorder (DLD) show difficulties later with theory of mind (ToM)…

Purpose: This study evaluates the extent to which automated indices of vocal development are stable and valid for predicting language in infants at increased familial likelihood for autism and/or language impairment and relatively lower likelihood infants. Method: A group of infants with autistic siblings (Sibs-autism; 20 infants) and a comparison…

Purpose: Despite known motor and spoken language impairments in autism spectrum disorder (ASD), the motor skills underlying speech production and their relationship with language skills have rarely been directly investigated in this population. Method: Thirty-nine autistic children (14 minimally verbal [MV], 25 verbal [V]) and 11 non-autistic…

Previous studies have shown that caregivers' sensitive, responsive interactions with young children can boost language development. We explored the association between caregivers' sensitivity and the vocabulary development of their 8-to-36-month-olds during COVID-19 when family routines were unexpectedly disrupted. Measuring caregivers'…

Deaf and hard-of-hearing (DHH) children with cochlear implants (CwCIs) constitute a heterogeneous population. A multitude of factors influence their spoken language development. There is evidence that CwCIs follow similar trajectories in language development as typically developing (TD) children but there is a lack of research on specific types of…

Purpose: Toddlers with Down syndrome (DS) showcase comparable or higher rates of gestures than chronological age-- and language-matched toddlers without DS. Little is known about how gesture use in toddlers with DS relates to multiple domains of development, including motor, pragmatics, language, and visual reception (VR) skills. Unexplored is…

This study aimed to adapt and validate the Word Complexity Measure (WCM) for Persian-speaking toddlers. The WCM is a tool for assessing phonological complexity, originally proposed by Stoel-Gammon. The study was conducted in two phases: (1) adapting the WCM parameters to the Persian language and (2) conducting a validation study with 60…

During the second year of life, children acquire words and expand their receptive and expressive vocabularies at a rapid pace. At this age, toddlers' phonological abilities are also developing rapidly. The current study investigated the effect of phonological complexity of words on the order in which they are acquired, receptively and…