Recognized as a simple communicative behavior, referential pointing is cognitively complex because it invites a communicator to consider an addressee's knowledge. Although we know referential pointing is affected by addressees’ physical location, it remains unclear whether and how communicators’ inferences about addressees’ mental representation of the interaction space influence sensorimotor control of referential pointing. The communicative perspective-taking task requires a communicator to point at one out of multiple referents either to instruct an addressee which one should be selected (communicative, COM) (...) or to predict which one the addressee will select (non-communicative, NCOM), based on either which referents can be seen (Level-1 perspective-taking, PT1) or how the referents were perceived (Level-2 perspective-taking, PT2) by the addressee. Communicators took longer to initiate the movements in PT2 than PT1 trials, and they held their pointing fingers for longer at the referent in COM than NCOM trials. The novel findings of this study pertain to trajectory control of the pointing movements. Increasing both communicative and perspective-taking demands led to longer pointing trajectories, with an under-additive interaction between those two experimental factors. This finding suggests that participants generate communicative behaviors that are as informative as required rather than overly exaggerated displays, by integrating communicative and perspective-taking information hierarchically during sensorimotor control. This observation has consequences for models of human communication. It implies that the format of communicative and perspective-taking knowledge needs to be commensurate with the movement dynamics controlled by the sensorimotor system. (shrink)

Adult-infant early dyadic interactions have been extensively explored by developmental psychologists. Around the age of 2 months, infants already demonstrate complex, delicate and very sensitive behaviors that seem to express their ability to interact and share emotions with their caregivers. This paper presents 3 pilot studies of parent-infant dyadic interaction in various set-ups. The first two present longitudinal data collected on two infants aged between 1 and 6 months and their mothers. We analyzed the development of coordination between them, at (...) the motor and at the vocal level. The 3rd pilot study aims to explore interpersonal coordination in both vocal behavior and motor activity for one infant and his mother at 2, 4 and 6 months. These pilot studies however leave a number of questions open concerning developmental changes and infants’ progressive mastery of interaction. We identify areas worth examining and try to tease out specific issues that may help develop new methodological pathways for the study of early naturalistic social interaction. We assume that a continuous, rather than discrete, approach would better capture the changes taking place in the various communicative modalities, while also displaying each dyad’s specificity and the narrative dimension of social engagement between infants and caregivers. (shrink)