Two kinds of visual perspective taking

Visual perspective taking can be used to determine where objects are located relative toanother agent, or whether the agent can see a particular object. Four experiments indicated that different processes provide these different kinds of information. When participants were asked to report whether an object was to the left or to the right of another agent, response times (RTs) increased with increasing angular distance between the participant and the agent, suggesting that participants mentally transformed their perspective to align it with that of the agent. For visibility judgments, RTs were independent of the angle between the participant and the agent but increased with the distance between the agent and the object, suggesting that participants traced the agent's line of sight. Together, these data suggest that perspective taking encompasses at least two qualitatively different computational processes: one that updates the viewer's imagined perspective, and one that traces a line of sight.