M.D. Rutherford¹ (), Esin Gürcan¹; ¹McMaster University

Autistic individuals have difficulty processing information in the eye region, and autistic traits are more common in their family members. In this longitudinal study, we examined looking to eyes and faces in infants with and without relatives with autism, using faces with open or closed eyes. Infants were recruited at 3, 6, 9, and 12 months, and later assessed for autism. A linear mixed model was used to predict preferential looking toward the eyes. There were main effects for open eyes at both 9 (t(335) = -2.70, p = 0.007; Std.beta = -0.57) and 12 months (t(335) = -2.03, p = 0.043; Std.beta = -0.43), and relatedness to autism (t(335) = -2.99, p = 0.003; Std.beta = -0.89). The interactions between age and relatedness to autism were significant at all age points: 6 months (t(335) = 2.02, p = 0.044; Std.beta = 0.73), 9 months (t(335) = 2.82, p = 0.005; Std.beta = 0.99), and 12 months (t(335) = 2.31, p = 0.021; Std.beta = 0.81). Infants preferred looked to the eyes rather than the mouth at 6 months (t(239) = -2.00, p = 0.047; Std.beta = -0.51) and 12 months (t(239) = -3.18, p = 0.002; Std.beta = -0.84). Relatedness to autism was marginally predicted this preference (p = 0.063). The interactions were significant at 6 (t(239) = 2.04, p = 0.042; Std.beta = 0.74) and 12 months (t(239) = 2.48, p = 0.014; Std.beta = 0.95). The comparison group initially preferred the eyes less but developed a stronger preference over time, surpassing the high-risk group. At 9 months, they preferred open eyes more, though this wasn't seen in the eyes vs. mouth task, possibly reflecting typical language-related attention to the mouth.

Acknowledgements: This research was funded by Natural Sciences and Engineering Research Council of Canada grant to M.D. Rutherford