Know thine own action

Abstract

To what extent can we recognize self-generated actions from those performed by others, when observing their visual effects? In a recent study, Knoblich and Prinz [J. Exp. Psychol. Hum. Percept. Perform. 27, 456–465] found that subjects could do so, in a task in which they first drew or traced familiar and unfamiliar characters without visual feedback. A week later (to eliminate short-term memory influences), the same subjects watched kinematic displays of their own movements, or those produced by others. Surprisingly, subjects could distinguish their own traces reliably better than chance, for unfamiliar as well as familiar characters, even when overall size and duration of the traces were eliminated as possible cues. The conclusion is that people recognize their own movements from their detailed kinematic properties. The authors argue that this result is evidence for a contribution of motor planning mechanisms to perception, and for a common coding in the brain for perception and action. MW