Humans and Monkeys Distinguish Between Self-generated, Opposing, and Random Actions

The sense of self-agency results from monitoring the relationship between prior thoughts and action plans, sensorimotor information, and perceived outcomes. It is thought to be an important factor underlying self-recognition and self-awareness. Three experiments investigated the sense of self-agency in humans and rhesus macaques (Macaca mulatta). First, humans were asked to move a cursor with a joystick while several distractor cursors also moved on-screen. They were asked to identify either the cursor they were controlling, or a distractor using visual cues alone. Six rhesus macaques were then given a similar task in which they needed to identify a self-controlled cursor that was paired with several different types of distractors. Both groups were able to identify the self-controlled cursor, and monkeys performed best when the oppositely moving cursor was the distractor. A third experiment showed that humans, like macaques, use both perceptual and self-agency information to make decisions.