This study investigates the influence of semantic maturation on early lexical development by examining the impact of contextual diversity--known to influence semantic development--on word promotion from receptive to productive vocabularies (i.e., comprehension-expression gap). Study 1 compares the vocabularies of 3685 American-English-speaking…

Maternal responses to infant facial expressions were examined in two socioeconomically diverse samples of South African mothers (Study I, N = 111; and Study II, N = 214; age: 17-44 years) using pupil and gaze tracking. Study I showed increased pupil response to infant distress expressions in groups recruited from private as compared to public…

Studies of infant motor development in autism spectrum disorder (ASD) have increased in recent years. This article synthesized this literature through meta-analysis to assess (a) whether infant motor ability differs in ASD relative to neurotypical controls; and (b) whether motor ability and communication are related in infants with ASD. Study 1…

This study examined differences in visual attention as a function of label learning from 6 to 9 months of age. Before and after 3 months of parent-directed storybook training with computer-generated novel objects, event-related potentials and visual fixations were recorded while infants viewed trained and untrained images (n = 23). Relative to a…

Two independent cohorts (N = 155, N = 126) of infants at high and low risk for autism spectrum disorder (ASD) were followed prospectively between 6 and 36 months of age, when n = 46 were diagnosed with ASD. Gaze to adult faces was coded--during a developmental assessment (Cohort 1) or a play interaction (Cohort 2). Across both cohorts, most…

Preterm birth and Neonatal Intensive Care Unit (NICU) stay are early adverse stressful experiences, which may result in an altered temperamental profile. The serotonin transporter gene ("SLC6A4"), which has been linked to infant temperament, is susceptible to epigenetic regulation associated with early stressful experience. This study…

Amid growing controversy about the oft-cited "30-million-word gap," this investigation uses language data from five American communities across the socioeconomic spectrum to test, for the first time, Hart and Risley's (1995) claim that poor children hear 30 million fewer words than their middle-class counterparts during the early years…

This study investigated how great apes and human infants use imperative pointing to request objects. In a series of three experiments (infants, N = 44; apes, N = 12), subjects were given the opportunity to either point to a desired object from a distance or else to approach closer and request it proximally. The apes always approached close to the…

Visual information influences speech perception in both infants and adults. It is still unknown whether lexical representations are multisensory. To address this question, we exposed 18-month-old infants (n = 32) and adults (n = 32) to new word-object pairings: Participants either heard the acoustic form of the words or saw the talking face in…

In some areas of rural Africa, long-standing cultural traditions and beliefs may discourage parents from verbally engaging with their young children. This study assessed the effectiveness of a parenting program designed to encourage verbal engagement between caregivers and infants in Wolof-speaking villages in rural Senegal. Caregivers (n = 443)…

This study investigated transfer effects of gaze-interactive attention training to more complex social and cognitive skills in infancy. Seventy 9-month-olds were assigned to a training group (n = 35) or an active control group (n = 35). Before, after, and at 6-week follow-up both groups completed an assessment battery assessing transfer to…

Cognitive impairment is common among children born very preterm (VPT), yet little is known about how this risk changes over time. To examine this issue, a regional cohort of 110 VPT (= 32 weeks gestation) and 113 full-term (FT) born children was prospectively assessed at ages 4, 6, 9, and 12 years using the Wechsler Preschool and Primary Scale of…

Comparisons of cognitive processing in monolinguals and bilinguals have revealed a bilingual advantage in inhibitory control. Recent studies have demonstrated advantages associated with exposure to two languages in infancy. However, the domain specificity and scope of the infant bilingual advantage in infancy remains unclear. In the present study,…

In this study, 6-month-old infants' visual working memory for a static feature (color) and a dynamic feature (rotational motion) was compared. Comparing infants' use of different features can only be done properly if experimental manipulations to those features are equally salient (Kaldy & Blaser, 2009; Kaldy, Blaser, & Leslie,…

There is little evidence that infants learn from infant-oriented educational videos and television programming. This 4-week longitudinal experiment investigated 15-month-olds' (N = 92) ability to learn American Sign Language signs (e.g., patting head for hat) from at-home viewing of instructional video, either with or without parent support,…