Use of longitudinal EEG measures in estimating language development in infants with and without familial risk for autism spectrum disorder.

Carol L Wilkinson,April R Levin,Laurel J Gabard-Durnam,Helen Tager-Flusberg,Kush Kapur,Charles A Nelson

doi:10.1162/nol_a_00002

Abstract

Language development in children with autism spectrum disorder (ASD) varies greatly among affected individuals and is a strong predictor of later outcomes. Younger siblings of children with ASD have increased risk of ASD, but also language delay. Identifying neural markers of language outcomes in infant siblings could facilitate earlier intervention and improved outcomes. This study aimed to determine whether EEG measures from the first 2-years of life can explain heterogeneity in language development in children at low- and high-risk for ASD, and to determine whether associations between EEG measures and language development are different depending on ASD risk status or later ASD diagnosis. In this prospective longitudinal study EEG measures collected between 3-24 months were used in a multivariate linear regression model to estimate participants' 24-month language development. Individual baseline longitudinal EEG measures included (1) the slope of EEG power across 3-12 months or 3-24 months of life for 6 canonical frequency bands, (2) estimated EEG power at age 6-months for the same frequency bands, and (3) terms representing the interaction between ASD risk status and EEG power measures. Modeled 24-month language scores using EEG data from either the first 2-years (Pearson R = 0.70, 95% CI 0.595-0.783, P=1x10-18) or the first year of life (Pearson R=0.66, 95% CI 0.540-0.761, P=2.5x10-14) were highly correlated with observed scores. All models included significant interaction effects of risk on EEG measures, suggesting that EEG-language associations are different depending on risk status, and that different brain mechanisms effect language development in low-versus high-risk infants.

Highlights

Children with autism spectrum disorder (ASD) have striking heterogeneity in their early language development (Anderson et al, 2007; Kjelgaard & Tager-Flusberg, 2001; Pickles, Anderson, & Lord, 2014)
Developmental trajectories of EEG power across the six frequency bands are shown in Figure 1, subdivided by outcome group (LR, HR-NoASD, and high-risk infants with ASD (HR-ASD))
To test whether EEG predictors of language were different in low- versus high-risk infants, Model 1 allowed for potential two-way interactions between risk status and all EEG parameters included in the model

Summary

Introduction

Children with autism spectrum disorder (ASD) have striking heterogeneity in their early language development (Anderson et al, 2007; Kjelgaard & Tager-Flusberg, 2001; Pickles, Anderson, & Lord, 2014). Longitudinal large population-based studies have identified various risk factors on the individual (gender, prematurity), familial (maternal education), and environmental (income) levels that influence language development (Reilly et al, 2007; Schjølberg, Eadie, Zachrisson, Oyen, & Prior, 2011). Across studies these factors consistently account for 4%–7% of variance in language outcomes in 2-year-olds, suggesting that additional factors play an important role in a child’s early language trajectory. Studying the neural mechanisms underlying language development in high-risk children may shed light on early language delay as a whole, and allow for earlier detection before delays in language can be measured behaviorally

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