Mothers’ Infant-Directed Gaze During Object Demonstration Highlights Action Boundaries and Goals

When demonstrating objects to young children, parents use specialized action features, called “motionese,” which elicit attention and facilitate imitation. We hypothesized that the timing of mothers' infant-directed eye gaze in such interactions may provide systematic cues to the structure of action. We asked 35 mothers to demonstrate a series of tasks on objects to their 7- and 12-mo-old infants, with three objects affording enabling sequences leading to a salient goal, and three objects affording arbitrary sequences with no goal. We found that mothers' infant-directed gaze was more aligned with action boundary points than expected by chance, and was particularly tightly aligned with the final actions of enabling sequences. For 7- but not 12-mo-olds, mothers spent more time with arbitrary than enabling-sequence objects, and provided especially tight alignment for action initiations relative to completions. These findings suggest that infants may be privy to patterns of information in mothers' gaze which signal action boundaries and particularly highlight action goals, and that these patterns shift based on the age or knowledge state of the learner.