Some Variables Influencing Reports of Directional Apparent Movement

Abstract

A moderate empiricist view about perception of apparent movement states that past experience may influence the Gestalt “tendency to total assimilation” in bilateral apparent movement. This hypothesis was tested by comparing the responses to bilateral apparent movement of 38 experimental Ss, who previously practiced unilateral apparent movement, with the responses of 25 control Ss who did not receive such practice. When experimental Ss were relatively unbiased in directional preference before practice, they increased their preferences for either the left or the right direction in the bilateral apparent movement pattern as a result of practice. This increase occurred in the direction practiced when Ss with initial left bias practiced unilateral apparent movement to the right, or Ss with initial right bias practiced unilateral apparent movement to the left. However, when practice reinforced the initial bias it seemed to “boomerang.” All Ss tended to reduce or reverse their initial directional bias regardless of the experimental treatment and practicing a specific direction was effective only when it supported this basic tendency of bias reduction.