Aki TSURUHARA and Hirohiko KANEKO

Imaging Science and Engineering Laboratory, Tokyo Institute of Technology, R2-60, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan

(Received March 20, 2006; Accepted May 30, 2006)

Effects of motion, implied direction in a static stimulus and displacement on postural control were examined independently. In Experiment 1, rotation of a random-dot stimulus was presented. In Experiments 2 and 3, photographic slides of natural scenes were used; participants closed their eyes during stimulus rotation to eliminate motion information. In Experiment 2, the stimulus was presented upright initially, then presented again with a tilt. In Experiment 3, the order was reversed to separate the effects of implied direction and displacement. Results showed that all information of motion, implied direction, and displacement had some effect on postural control, although visual information of motion has been presumed to have a principal effect on postural control. Results suggested that the effects of implied direction might reflect an immediate processing of information. The effects of displacement and motion might reflect a continuous processing of information.

Key words: postural control, large-visual-stimulus, tilt, motion, displacement, vertical and horizontal information, direction