Interpersonal predictive coding: Communicative gestures increase the likelihood of perceiving a second agent

In the context of interacting activities requiring close body contact such as fighting or dancing, the actions of one agent can be used to predict the actions of the second agent (Neri, Luu & Levy, 2006). In the present two studies we investigated whether interpersonal predictive coding extends to interactive activities - such as communicative interactions - in which no physical contingency is implied between the movements of the interacting individuals. Participants observed point-light displays of two agents (A and B) performing separate actions. In the communicative condition, the action performed by agent B responded to a communicative gesture performed by agent A. In the individual condition, agent A's communicative action was substituted with a non-communicative action. Using simultaneous masking detection tasks, we demonstrated that observing the communicative gesture performed by agent A: a) enhanced visual discrimination of agentB (Experiment 1), and b) increased the likelihood of perceiving agent B, also when agent B was in fact not present (Experiment 2). These finding complements and extends previous evidence for interpersonal predictive coding, suggesting that the communicative gestures of one agent can serve as a predictor for the expected actions of the respondent, even if no physical contact between agents is implied.