2017-Oosterwijk-SciReports

Referential pointing is a characteristically human behavior, which involves moving a nger through space to direct an addressee towards a desired mental state. Planning this type of action requires
an interface between sensorimotor and conceptual abilities. A simple interface could supplement spatially-guided motor routines with communicative-ostensive cues. For instance, a pointing nger held still for an extended period of time could aid the addressee’s understanding, without altering the movement’s trajectory. A more complex interface would entail communicative knowledge penetrating the sensorimotor system and directly a ecting pointing trajectories. We compare these two possibilities using motion analyses of referential pointing during multi-agent interactions. We observed that communicators produced ostensive cues that were sensitive to the communicative context. Crucially, we also observed pervasive adaptations to the pointing trajectories: they were tailored to
the communicative context and to partner-speci c information. These ndings indicate that human referential pointing is planned and controlled on the basis of partner-speci c knowledge, over and above the tagging of motor routines with ostensive cues.