Caregiver Speech and Brain-Behavior Development in Infants At-Risk for ASD

PROJECT SUMMARY Caregiver Speech and Brain-Behavior Development in Infants At-Risk for Autism Spectrum Disorder The defining symptoms of autism spectrum disorder emerge only after an initial presymptomatic period during the first year of life. The first year of life is also a time of tremendous growth and neuroplasticity for the infant brain. The overall goal of the proposed longitudinal study is to enable and inform presymptomatic infant interventions for autism by examining the relationships between infant vocalizations, caregiver speech, and brain-behavior development in infants at high familial risk for autism. Conceptually, the project focuses on the potential protective effects of caregiver speech on infant development. The proposed study is a companion to and collaboration with the IBIS Network-Early Prediction Study, an NIH-sponsored study of 250 infants at high familial risk for autism. All infants in the study have an older sibling with autism. These high-risk infants have a 20% probability of developing autism themselves. Ecologically valid day-long home language recordings will be collected when infants are 6 and 12 months of age. A state-of-the-art automated processing pipeline will used to estimate daily counts of infant and caregiver speech quality and quantity. Micro-level targeted annotation will be applied to semi-structured, parent-infant play sessions collected in the lab. Automated processing pipelines and micro-level targeted annotation will be used to generate multivariate infant vocalizations and caregiver speech data. Infant vocalizations will be classified as speech-like or non-speech-like (delight or distress). Caregiver speech variables include lexical diversity, mean length utterance, and temporal contingency. The study will determine if infant vocalizations predict subsequent autism diagnosis and later language and social communication scores, and specify the relationship between caregiver speech and infant communication skills. Diffusion MRI will be collected when infants are 6, 12, and 24 months of age by the Early Prediction Study. The proposed study will determine if multivariate caregiver speech is related to targeted prefrontal and temporal brain regions. By determining if caregiver speech can have a protective effect on brain development, we forge a new scientific approach to studying communication development in infants at high-risk for autism. As first-year autism detection and presymptomatic intervention become increasingly feasible, an evidence base is needed to inform interventions. The proposed study will identify infant-based language and communication risk markers, caregiver-based intervention targets, and brain-based monitoring biomarkers to guide presymptomatic intervention for autism that is parent-mediated and delivered in the natural setting.