Jana M. Iverson

Recurrence risk for autism spectrum disorders: A baby siblings research consortium study

OBJECTIVE: The recurrence risk of autism spectrum disorders (ASD) is estimated to be between 3% and 10%, but previous research was limited by small sample sizes and biases related to ascertainment, reporting, and stoppage factors. This study used prospective methods to obtain an updated estimate of sibling recurrence risk for ASD. METHODS: A prospective longitudinal study of infants at risk for ASD was conducted by a multisite international network, the Baby Siblings Research Consortium. Infants (n = 664) with an older biological sibling with ASD were followed from early in life to 36 months, when they were classified as having or not having ASD. An ASD classification required surpassing the cutoff of the Autism Diagnostic Observation Schedule and receiving a clinical diagnosis from an expert clinician. RESULTS: A total of 18.7% of the infants developed ASD. Infant gender and the presence of >1 older affected sibling were significant predictors of ASD outcome, and there was an almost threefold increase in risk for male subjects and an additional twofold increase in risk if there was >1 older affected sibling. The age of the infant at study enrollment, the gender and functioning level of the infants older sibling, and other demographic factors did not predict ASD outcome. CONCLUSIONS: The sibling recurrence rate of ASD is higher than suggested by previous estimates. The size of the current sample and prospective nature of data collection minimized many limitations of previous studies of sibling recurrence. Clinical implications, including genetic counseling, are discussed.

Gesture Paves the Way for Language Development

In development, children often use gesture to communicate before they use words. The question is whether these gestures merely precede language development or are fundamentally tied to it. We examined 10 children making the transition from single words to two-word combinations and found that gesture had a tight relation to the childrens lexical and syntactic development. First, a great many of the lexical items that each child produced initially in gesture later moved to that childs verbal lexicon. Second, children who were first to produce gesture-plus-word combinations conveying two elements in a proposition (point at bird and say “nap”) were also first to produce two-word combinations (“bird nap”). Changes in gesture thus not only predate but also predict changes in language, suggesting that early gesture may be paving the way for future developments in language.

Clinical Assessment and Management of Toddlers With Suspected Autism Spectrum Disorder: Insights From Studies of High-Risk Infants

With increased public awareness of the early signs and recent American Academy of Pediatrics recommendations that all 18- and 24-month-olds be screened for autism spectrum disorders, there is an increasing need for diagnostic assessment of very young children. However, unique challenges exist in applying current diagnostic guidelines for autism spectrum disorders to children under the age of 2 years. In this article, we address challenges related to early detection, diagnosis, and treatment of autism spectrum disorders in this age group. We provide a comprehensive review of findings from recent studies on the early development of children with autism spectrum disorders, summarizing current knowledge on early signs of autism spectrum disorders, the screening properties of early detection tools, and current best practice for diagnostic assessment of autism spectrum disorders before 2 years of age. We also outline principles of effective intervention for children under the age of 2 with suspected/confirmed autism spectrum disorders. It is hoped that ongoing studies will provide an even stronger foundation for evidence-based diagnostic and intervention approaches for this critically important age group.

Why people gesture when they speak

People use gestures when they talk, but is this behaviour learned from watching others move their hands when talking? Individuals who are blind from birth never see such gestures and so have no model for gesturing. But here we show that congenitally blind speakers gesture despite their lack of a visual model, even when they speak to a blind listener. Gestures therefore require neither a model nor an observant partner.

Gestures and words during the transition to two-word speech

This study explores the communicative use of the gestural and vocal modalities by normally developing Italian children during the transition from one- to two-word speech. We analysed the spontaneous production of 12 children at 1;4 and at 1;8, focusing on the use of two-element combinations of words and/or gestures. Results indicated that use of gesture and gesture-word combinations during the transition to two-word speech is a robust feature of communicative development across a relatively large number of children in a rich gestural culture, and that the number of gesture-word and two-word combinations increased significantly from 1;4 to 1;8. Number of gestures and gesture-word combinations produced at 1;4 was also predictive of total vocal production at 1;8. Findings are discussed in terms of the role of gesture as a transitional device en route to two-word speech.

From communication to language in two modalities

This study explores the interplay between gestures and words in the early vocabularies of 12 normally developing Italian children at 16 and 20 months of age. Focusing on spontaneous production of verbal and gestural types and tokens, we assessed the diversity and semantic content of the verbal and gestural vocabularies. Results indicated that the gestural modality was utilized extensively by all subjects. Whereas only half the group had more gesture than word types in their repertoires at 16 months, eight of the 12 subjects exhibited a clear preference for communication in the gestural modality, employing a larger number of gestural than verbal tokens. By 20 months, almost all of the subjects had many more word types and used words more frequently than gestures. By providing some sensorimotor components of an object-referent, gestures may lessen the demand on developing symbolic skills and aid the child in the transition to highly abstract word-referent relationships.

Relationship between gestures and words in children with Down's syndrome and typically developing children in the early stages of communicative development

BACKGROUND Previous research has emphasized the importance of gesture in early communicative development. These studies have reported that gestures are used frequently during the first two years of life and may play a transitional role in the language acquisition process. Although there are now numerous descriptions of the relationship between gesture and the developing language system in typically-developing (TD) children, relatively little is known about the nature and early development of the gesture-language system in children with developmental disorders involving specific profiles of language delay and/or impairment. PRIMARY OBJECTIVE The aim of this study is to compare early word and gesture use in children with DS and in typically-developing children to investigate potential differences in the relationship between gestural and verbal communication in early language development. METHODS AND PROCEDURES Ten children from upper-middle class families participated in the study. The five children with DS (3 boys and 2 girls) had an average chronological age of 47.6 months, an average mental age of 22.4 months, and an average language age of 18 months. Each child with DS was matched to a typically developing child on the basis of gender, language age, and observed expressive vocabulary size. Children were videotaped for 30 minutes as they interacted spontaneously with their mothers. All communicative and intelligible gestures and words produced by the children were transcribed from the videotapes. Data analyses focused on: a) overall production of gestures and words (i.e., gesture and word tokens); b) the size of childrens gestural and verbal repertoires (i.e., gesture and word types); and c) production and informational content of gesture-word combinations. MAIN OUTCOMES AND RESULTS Although children with DS had significantly smaller gestural repertoires than their language age-matched peers, there was no reliable difference between the two groups in the overall use of gesture. In addition, with DS produced two-element combinations (primarily gesture-word combinations) and did so at a rate comparable to that observed among their TD counterparts. However, no two-word combinations were observed among children with DS, and there were also group differences in the information contained in childrens gesture-word combinations. CONCLUSIONS Taken together, these findings suggest that in addition to the well-documented global delays in early communicative development, children with DS may exhibit additional pockets of delay, specifically in making the transition from one- to two-word speech. Results are further discussed in terms of their implications for understanding the organization of the developing gesture-language system and for the assessment of gesture in young children with communicative delays and disorders.

Learning to talk in a gesture-rich world: Early communication in Italian vs. American children

Italian children are immersed in a gesture-rich culture. Given the large gesture repertoire of Italian adults, young Italian children might be expected to develop a larger inventory of gestures than American children. If so, do these gestures impact the course of language learning? We examined gesture and speech production in Italian and US children between the onset of first words and the onset of two-word combinations. We found differences in the size of the gesture repertoires produced by the Italian vs. the American children, differences that were inversely related to the size of the childrens spoken vocabularies. Despite these differences in gesture vocabulary, in both cultures we found that gesture + speech combinations reliably predicted the onset of two-word combinations, underscoring the robustness of gesture as a harbinger of linguistic development.

Fine Motor Skill Predicts Expressive Language in Infant Siblings of Children with Autism.

We investigated whether fine motor and expressive language skills are related in the later-born siblings of children with autism (heightened-risk, HR infants) who are at increased risk for language delays. We observed 34 HR infants longitudinally from 12 to 36 months. We used parent report and standardized observation measures to assess fine motor skill from 12 to 24 months in HR infants (Study 1) and its relation to later expressive vocabulary at 36 months in HR infants (Study 2). In Study 1, we also included 25 infants without a family history of autism to serve as a normative comparison group for a parent-report fine motor measure. We found that HR infants exhibited fine motor delays between 12 and 24 months and expressive vocabulary delays at 36 months. Further, fine motor skill significantly predicted expressive language at 36 months. Fine motor and expressive language skills are related early in development in HR infants, who, as a group, exhibit risk for delays in both. Our findings highlight the importance of considering fine motor skill in children at risk for language impairments and may have implications for early identification of expressive language difficulties.

Atypical Cry Acoustics in 6-Month-Old Infants at Risk for Autism Spectrum Disorder

This study examined differences in acoustic characteristics of infant cries in a sample of babies at risk for autism and a low‐risk comparison group. Cry samples derived from vocal recordings of 6‐month‐old infants at risk for autism spectrum disorder (ASD; n = 21) and low‐risk infants (n = 18) were subjected to acoustic analyses using analysis software designed for this purpose. Cries were categorized as either pain‐related or non‐pain‐related based on videotape coding. At‐risk infants produced pain‐related cries with higher and more variable fundamental frequency (F 0) than low‐risk infants. At‐risk infants later classified with ASD at 36 months had among the highest F 0 values for both types of cries and produced cries that were more poorly phonated than those of nonautistic infants, reflecting cries that were less likely to be produced in a voiced mode. These results provide preliminary evidence that disruptions in cry acoustics may be part of an atypical vocal signature of autism in early life. Autism Res 2012, ••: ••–••.