The limits of visual mass perception

摘要

The theory of direct perception suggests that observers can accurately judge the mass of a box pickedup by a lifter shown in a point-light display. However, accurate perceptual performance may be limitedto specific circumstances. The purpose of the present study was to systematically examine the factorsthat determine perception of mass, including display type, lifting speed, response type, and lifter'sstrength. In contrast to previous research, a wider range of viewing manipulations of point-lightdisplay conditions was investigated. In Experiment 1, we first created a circumstance where observerscould accurately judge lifts of five box masses performed by a lifter of average strength. In Experiments2-5, we manipulated the spatial and temporal aspects of the lift, the judgement type, and lifter'sstrength, respectively. Results showed that mass judgement gets worse whenever the context deviatesfrom ideal conditions, such as when only the lifted object was shown, when video play speed waschanged, or when lifters of different strength performed the same task. In conclusion, observers'perception of kinetic properties is compromised whenever viewing conditions are not ideal.