Perception of Audiovisual Synchrony Under Varying Degrees of Social Context in Infants with Autism

Background: In recent research, we found that two-year-olds with autism failed to orient towards point-light displays of human biological motion. Rather than giving preferential attention to biological motion, children with autism oriented towards non-social, physical contingencies present within the stimuli—contingencies that were disregarded by control children. These results indicated that a skill present in two-day-old, typically-developing infants, as well as in chronologically-, nonverbally-, and verbally-matched 2-year-old control children, was already atypical in very young children with autism. In its place, these toddlers with autism demonstrated intact processing of a physical contingency: audiovisual synchrony

Objectives: The goal of the current project is to downward extend this line of research to younger infants under more controlled conditions in order to explicate the above finding. Our aims are (1) to assess the sensitivity of infants with ASD to audiovisual synchrony devoid of social context; and (2) to measure the effect of varying social contexts upon the preferential attentional patterns of infants with ASD relative to audiovisual synchronous stimuli.

Methods: Three groups of children – infants with ASD, typically-developing infants (TD), and infants with non-autistic developmental-delays (DD), ages 12-24 months – participated in two series of experiments based on a preferential looking paradigm to split-screen presentations. We used stimuli that varied in degree of social context: pure tones, sine wave speech, and naturalistic speech in the auditory modality, and circles, ellipses and dynamic faces in the visual modality. The first series of experiments tested baseline sensitivities to audiovisual synchrony. The second series of experiments tested how sensitivity to audiovisual synchrony was affected by varying the social context of the stimuli. Eye-tracking technology measured infants’ looking.

Results: Preliminary results show that infants with autism are as sensitive as their peers to the perception of audiovisual synchrony. However, audiovisual synchrony detection in infants with autism is less influenced by accompanying social context: while the introduction of biasing social context altered the preferential viewing patterns of TD and DD controls, the change in contextual information did not alter the viewing patterns of infants with ASD.

Conclusions: The present study suggests that in the developmental experience of children with autism, physical contingencies of coincident light and sound are more salient than the surrounding social context. Future investigations will benefit from studies, starting still earlier in life, of the developmental unfolding of such selective learning profiles. Exactly which signals are spontaneously attended to and which are missed, and the consequences thereof for structural and functional brain development, may shed light on the neurobiological anomalies that predispose these altered avenues of learning.