Abstract
Human observers can sometimes attribute animacy or agency to non-living objects, such as robots, perceiving them as if they were alive. In particular, the movement pattern of non-living things is a key feature for perceiving life. It is also well known that the pattern of the eyes is also an important feature for the perception of the sense of life. The present study investigated how the animacy impression of a cube-shaped robot moving along the Perlin noise trajectory could be influenced by the visual patterns of the eyes, such as eye positions and gaze directions. The eyes were presented on the top surface of the cube-shaped robot. Participants were asked to rate animacy impressions of the robot. These impressions included the impression of a live animal, having intention and moving in a self-propelled manner. These impressions were consistently higher when the eyes were presented on the side of the robot's direction of motion than when they were presented on the side orthogonal to, or opposite to, the robot's direction of motion. In general, the animacy impressions were largely comparable regardless of whether the robot's gaze direction aligned with, was orthogonal to, or opposed its motion direction. However, the impression of intention was stronger when the gaze direction at the front side of the object was consistent with the motion direction than when it was inconsistent. We discuss the evolutionary role of eye position in determining animacy impressions.