Children's early language environments are related to later development. Little is known about this association in siblings of children with autism spectrum disorder (ASD), who often experience language delays or have ASD. Fifty-nine 9-month-old infants at high or low familial risk for ASD contributed full-day in-home language recordings. High-risk infants produced more vocalizations than low-risk peers; conversational turns and adult words did not differ by group. Vocalization differences were driven by a subgroup of “hypervocal” infants. Despite more vocalizations overall, these infants engaged in less social babbling during a standardized clinic assessment, and they experienced fewer conversational turns relative to their rate of vocalizations. Two ways in which these individual and environmental differences may relate to subsequent development are discussed.
Bibliographical noteFunding Information:
This study included 59 infants from the Infant Brain Imaging Study (IBIS), an ongoing longitudinal study of infants at high and low familial risk for ASD. The IBIS Network is an Autism Center for Excellence funded by the National Institutes of Health (R01 HD055741). The network includes four clinical sites: University of North Carolina, Chapel Hill; University of Washington, Seattle; The Children’s Hospital of Philadelphia; and Washington University, St. Louis; and data coordination at Montreal Neurological Institute, McGill University. Parents provided written informed consent prior to participating in this study. Procedures for this study were approved by the institutional review boards at each clinical data collection site.
The authors thank the children and their families for their ongoing participation in this longitudinal study as well as the numerous research assistant and volunteers who have worked on this project. This work was supported by grants through the National Institutes of Health (HD055741 PI Joseph Piven, HD055741-S1 PI Joseph Piven, HD003110 PI Joseph Piven, U54 EB005149 PI Ron Kikinis), the National Science Foundation (IIS-1029679 PI James Rehg), the Simons Foundation (SFARI Grant 140209). Meghan R. Swanson was supported by a Pathway to Independence Award (K99-MH108700) from NIMH and a National Research Service Award (T32-HD40127) from NICHD. Jason J. Wolff was supported by a grant from the National Institute of Mental Health (K01-101653). LENA Research Foundation donated the clothing and digital recording devices used to collect the data presented herein. The funders had no role in study design, data collection, analysis, data interpretation, or the writing of the report.
© 2017 The Authors. Child Development © 2017 Society for Research in Child Development, Inc.