Contingencies Between Infants' Gaze, Vocal, and Manual Actions and Mothers' Object-Naming: Longitudinal Changes From 4 to 9 Months.

Infants' early motor actions help organize social interactions, forming the context of caregiver speech. We investigated changes across the first year in social contingencies between infant gaze and object exploration, and mothers' speech. We recorded mother-infant object play at 4, 6, and 9 months, identifying infants' and mothers' gaze and hand actions, and mothers' object naming and general utterances. Mothers named objects more when infants vocalized, looked at objects or the mother's face, or handled multiple objects. As infants aged, their increasing object exploration created opportunities for caregiver contingencies and changed how gaze and hands accompany object naming over time.