Temporal Dynamics of Action Perception: The Role of Biological Appearance and Motion Kinematics

Abstract

We studied action perception and the role of visual form and visual motion kinematics of the observed agent using a stimulus set of human and humanoid robot actions and electroencephalogram (EEG). Participants viewed 2s. videos of three agents (Human, Android, Robot) performing recognizable actions: Human had biological form and motion, Android had biological form and non-biological motion, and Robot had non-biological form and non-biological motion. Early in processing (P200), Robot was distinguished from the other agents, likely due to low-level visual properties of the stimuli. We found a right temporal N170, which was most pronounced for Human, indicating possible modulation of this face- and body-sensitive ERP component by biological motion. There was a centro-parietal negativity (N300) that was most pronounced for Robot, and a later one (N400) for Human and Android. In the same time period (N300), Android was distinguished in the frontal channels from the other agents. A late positivity (P600) distinguished Human, again in frontal channels. These results highlight differential spatiotemporal cortical patterns during action perception depending on the viewed agent’s form and motion kinematics.