Magnitude Estimation of Velocity in the X,Y,and Z Axes

Abstract

The present study examined the perception of velocity along different axes. Participants viewed the movement of two small circles on a computer display and gave verbal responses for the perceived velocity of one of the circles relative to the other using the psychophysical method of magnitude estimation. Stimuli were presented along the x, y, and z axes. Other variables included direction traveled, time and distance constant, and velocity. Movement in the z axis was represented through angular expansion. As expected, results indicated that velocity judgments increased with increases in stimulus velocity. Perceived velocity was expected to be higher for vertical as compared to horizontal stimuli. The results provided partial support for this hypothesis. Estimates for velocity along the z axis were qualitatively different than for the other two axes. Further, velocity estimates depended upon whether the time or distance was held constant and suggest that the perception of velocity is tied to both spatial and temporal properties of the stimuli.