Sweep speed, time of exposure, and perceptual lag

The perceptual lag phenomenonly was investigated by varying motor speed and time of exposure to a noisy field. Ss were 90 male cadets used in a 3 X 3 factorial design. Three motor speeds of 1, 10, and 20 r.p.m. were used in conjunction with noisy field viewing times of 5, 10, and 30 minutes, respectively. Ss' speed estimations of a moving contour before and after exposure to a noisy field were analyzed. Results indicated that, of the three F ratios, only F (2, 81) = 34.01, p < .01 for revolutions per minute was significant. Results were discussed in terms of studies which showed that increasing the velocity of a moving sweep, within a certain range of velocities, leads to a distinct breakdown in the structuring of the visual field. This destructuring, in turn, presumably leads to the perceptual lag phenomenon by adding extrinsic noise to the intrinsic noise generated by the visual nervous system.