Visually-Perceived Momentum in Biological Motion: The Influence of Changes in Running Velocity.

The objective of this study was to elucidate the characteristics of visually perceived momentum of others' motions. Twenty participants watched and compared two consecutive point-light running motions: one at a fixed velocity of 8.0 km/h and the other at one of seven velocities (5.6, 6.4, 7.2, 8.0, 8.8, 9.6, and 10.4 km/h). They then evaluated which had greater momentum, or if they were the same. The results indicated that as the velocity deviated from the standard velocity of 8.0 km/h, the correct rates increased; in particular, the correct rate at 5.6 km/h, which differed the most from the standard velocity, was the greatest ( < .001). Additionally, the mean response times at 5.6 and 6.4 km/h, which were relatively smaller than the standard velocity, were significantly lower (both < .05). This study indicates that humans can accurately perceive the momentum of others' motions, consistent with previous studies demonstrating an accurate perception of the physical and mechanical properties of human-like motion.