Preferential Attention to Audiovisual Synchrony Predicts Language Ability in Toddlers with ASD
Objectives: Our goal was to test whether information-theoretic measures of differences in visual attention to audiovisual synchrony that discriminate between TD and ASD toddlers predict language ability in those children.
Methods: Toddlers with autism (N=34) and typically developing controls (N=20) participated in a simple preferential-looking paradigm based on split-screen presentation of video stimuli (faces and shapes) paired with audio stimuli (speech and tones). Using different combinations of video and audio stimuli, and manipulating audiovisual synchrony between the two, we tested for differences in attention to social and physical contingencies. Eye tracking was used to quantify response. Using machine-learning techniques, we derived optimal measures of overall attention and attention to social target across all stimulus combinations, focusing on responses to speech and non-speech. An optimal classifier was derived using a generalized likelihood ratio test calculated from the entire joint distribution of our measures across groups. Receiver operating characteristics were further used to quantify classification performance, using leave-one-out cross-validation with the log likelihood ratio as the test statistic. To determine the relationship between preferential attention to audiovisual synchrony and language ability, we calculated the correlation between the log likelihood ratio scores and the receptive and expressive language scores determined from clinical assessments using the Mullen Scales of Early Learning.
Results: We found significant correlations (P<0.05) between the log likelihood ratio scores (speech/non-speech conditions) and both receptive (r=-0.332/-0.394) and expressive (r=-0.413/-0.409) language scores.
Conclusions: Patterns of preferential attention to audiovisual synchrony that discriminate between ASD and TD children are also predictive of language ability in those children, suggesting that differential sensitivity to social and physical contingencies in talking faces is a pathway to spoken language in autism.