Agency and social affordance shape visual perception

Research on the sense of agency has shown that being the author of an action changes the way we estimate the timing and the intensity of the action-effect. Yet, there is a dearth of attempts to assess the influence of agency on perception per se. The present study used the Representational Momentum paradigm to measure participants' visual anticipation of movement while manipulating their agency. In line with previous literature emphasizing the impact of social factors on visual anticipation and on the sense of agency, we additionally investigated the modulating power of social affordances on the relationship between agency and visual anticipation. We conducted two experiments where participants viewed a virtual agent directing a handshake gesture toward a second virtual agent. In a first experiment, we addressed the role of agency on visual anticipation by comparing a condition in which participants triggered the virtual agent's gesture with a condition where the computer triggered the gesture. Results showed greater forward movement anticipation when participants triggered the gesture. The second experiment investigated how altering social interaction parameters (interindividual distance and body posture) modulated the relationship between agency and visual anticipation. The outcome contrasted with the first experiment, with participants anticipating a backward movement of the hand when the computer triggered the gesture and displaying a null anticipation when participants triggered the gesture. Those two experiments highlighted how active involvement and environmental affordance interact to shape perception and allowed us to propose an updated model of agency processing.