Your brain has a remarkable ability to extract and process biological cues from the deluge of visual information. It is highly sensitive to the movements of living things, especially those of other people – so much so that it conjures the illusion of movement from a picture of a moving body. Although static, such pictures trigger dynamic representations of the body, ‘motor images’ containing information about movement kinematics and timing. Researchers at the Institute of Cognitive Neuroscience in London now show that biological motion is processed unconsciously, and that the speed of apparent motion alters the perception of time.
Play around with this point light display and you’ll see that your brain has specialized mechanisms dedicated to recognizing and visually processing the human body and its movements. The demo shows that the brain is adept at inferring structure from motion, so thatwe readily perceive biological motion even when a minimum amount of information about the body is available. It also shows that the motions of the body contain information about sex, weight, emotional state and even some personality traits, and that we can extract this information effortlessly.