Poisson regulation in mother-infant gaze systems

We propose stochastic models for the interactive regulation of gaze on/off each partnerʹs face in mother/infant gaze as well as “turn-taking”. We infer that a Poisson timing mechanism indeed underlies the negative exponential distributions of gaze, providing a simplifying organizational principle for mother-infant communication, enabling both partners to predict the otherʹs behavior. The Poisson rate constants quantify how likely infant or mother is to gaze on or off in comparison to each other. Mothers are far more likely to initiate gaze than infants, and infants are far more likely to terminate gaze than mothers. Initiation of a gaze “turn” (the individual unilaterally initiates gaze) follows a simple Poisson rule for infants, but mothers initiate a gaze turn with the second occurrence of infantsʹ gaze termination. These turn findings suggest that mothers are using more history than infants in gaze turn regulation. For the infant, all three processes (gaze on, gaze off; gaze turn) are regulated by a Poisson process.