Fig. 1

Habituation task at 6 and 12 months. a Illustration of an idealized habituation function, showing the peak look measure. b Peak look duration at 6 months in the four groups (low-risk control, HR-ASD+, and HR-ASD-Neg). c Peak look duration at 12 months. d Illustration of the habituation procedure. e Mean position of the peak look in the looking sequence (in a, the peak look is the third in the sequence) at 6 months. f Mean position of the peak look at 12 months. All error bars are ±1 standard error