The effect of efference to the arm on visual adaptation to curvature: A replication

Ss inspected a curved line through a prism that made it appear straight, then moved one finger along the line in one of two ways. One way encouraged the learning of a new efferent program for a curved movement (learning). The other (accuracy) offered little opportunity for such learning. Replicating a finding by Festinger, Burnham, Ono, & Bamber (1967), the learning condition produced slightly, but significantly, more visual adaptation to curvature than did the accuracy condition. There was some suggestion that greater prismatic strength produced greater adaptation. The results support the idea that efferent commands to the arm can affect visual perception of contour shape.