Gait perception of part-reverse biological motion pattern produced by eight point-lights attached to the back of a walker

Abstract

The Johansson side-view point-light walker (PLW) gives a vivid impression of an invisible human, and the Cutting Cm (center of moment), determined by the relative widths of the shoulders and hips of the walker, is a well-known important parameter for sex identification of perceived gait, The back-view PLWs produced by the eight point-lights attached to the back of a walker also give a clear image of human gait (Sumi, 2000). In the present investigation, the part-reverse (P-R) PLWs were used as stimuli, In the P-R PLWs, the lower-half elements (knees and heels) of the back-view PLWs were arranged to be the reverse of their normal PLWs and the upper half elements (shoulders and hips) were arranged exactly the same as their normal PLWs. Results revealed that the P-R PLWs were identified correctly as often as the normal PLWs, indicating that the Cutting Cm is valid for the back-view PLWs. It was also found that, when the sex of the P-R PLW was identified correctly, the age was estimated to be younger, whereas when the sex was not identified correctly, the age was estimated to be older. This finding was discussed in relation to the difference between the data profiles obtained from the P-R PLWs and the normal PLWs. © 2005 Japanese Psychological Association. Published by Blackwell Publishers Ltd.