a display used in studies of biological motion perception and consisting of a dozen or so small lights attached to various joints and other parts of the body of an individual, with the body itself not visible. The movement of just the small lights (or a computer reproduction thereof) produces a compelling impression of the individual in motion. However, without movement, the lights are perceived as random and not as the individual. [devised in the 1970s by Swedish psychologist Gunnar Johansson (1911–1998)]