19848
Perception of Biological Motion and Integration of Audio-Visual Stimuli in Infants at Risk for Autism

Thursday, May 14, 2015: 5:30 PM-7:00 PM
Imperial Ballroom (Grand America Hotel)
H. S. Reuman1, R. Tillman2, T. Kim3, E. J. Levy1, K. Law1, A. Naples1, K. K. Stavropoulos1, A. T. Odonkor3, S. H. Kim1, E. Schoen Simmons1, K. K. Powell1, S. Macari4, F. Shic5, K. Chawarska4 and J. McPartland1, (1)Child Study Center, Yale University, New Haven, CT, (2)Clinical Psychology, University of Maryland, College Park, MD, (3)Yale University, New Haven, CT, (4)Child Study Center, Yale University School of Medicine, New Haven, CT, (5)Yale Child Study Center, Yale University School of Medicine, New Haven, CT
Background: Biological motion (BM) perception and multisensory integration (audio-visual synchrony; AVS) are critical processes in typical development that are implicated as potential mechanisms of dysfunction in ASD. In typical development, preferential attention to biological motion and successful detection of temporal contingency between auditory and visual events develop early in life and facilitate interpersonal interactions. Behavioral research indicates that these abilities are impaired in toddlers diagnosed with autism spectrum disorder (ASD). However, the developmental emergence and neural underpinnings of these abilities are poorly understood.

Objectives: Neural responses to BM and AVS were compared in infants at high-risk (HR; having an older sibling with ASD) and infants at normal risk (NR; no family history of ASD) for ASD. Through investigation of electrophysiological markers of BM and AVS, we aimed to (a) compare sensitivity to BM, (b) evaluate the degree of neural facilitation when processing multisensory stimuli, and (c) track the emergence of BM sensitivity and AVS facilitation to define typical vs. atypical trajectories.

Methods: Through a longitudinal design, HR (n=36), and NR (n= 42) infants were assessed at three-month intervals between three and twenty-four months. EEG was recorded with a 128-channel Hydrocel Geodesic Sensor net while infants viewed point-light displays illustrating BM and scrambled motion (SM; Experiment 1) or unimodal/bimodal auditory (tone) and visual (blue circle) stimuli (Experiment 2). In Experiment 1, two event-related potentials (ERPs) indexing BM perception (N200, negative deflection over right occipitotemporal scalp between 200-300ms; PSW, late anterior positive slow wave between 900-1500ms) were examined. In Experiment 2, two ERPs indexing multisensory integration (N100, negative deflection over fronto-central scalp between 90-145ms; N200, negative deflection over occipitotemporal scalp between 150-200ms) were assessed.

Results: Preliminary analyses from Experiment 1 found that neither HR nor NR infants exhibited significant differentiation between BM and SM (p>.05) at the six and nine-month time points. Descriptively, both groups exhibited attenuated N200 to BM, relative to SM, at six months, but this differentiation did not reach significance. NR infants, but not HR infants, continued to demonstrate this N200 attenuation to BM at nine months. In Experiment 2, 9 to 12 month NR infants exhibited a significantly enhanced N200 in response to AVS, (p=.01), whereas HR infants did not.

Conclusions: HR and NR infants elicited differential neural responses to BM at six months of age, and 9-12 month old HR infants exhibited neural atypicalities for AVS. These characteristic changes in neural response to BM and AVS over the first two years of life have the potential to serve as early indicators of ASD and to guide development of individually-tailored early interventions.

See more of: Early Development (<48 months)
See more of: Early Development (< 48 months)