Extent, Direction, and Latency of Autokinetic Movement as a Function of Placement of an Adjacent Light

Abstract

Four Os drew maps of their autokinetic movement for a central light when it was the only stimulus, and when another light was adjacent to it. Eight directions (at 45° intervals) at each of two distances from the central light (1.27 and 2.54 cm) were used to yield 16 different placements of the light-pairs. The addition of the second light in any placement resulted in a significant reduction in the amount of movement and an increase in its latency. At either of the distances used, both lights were still viewed in the fovea, and the results did not differ in this respect. The direction of the second light from the central one did exert a significant influence, however. The results are compatible with the view that autokinesis results from a combination of eye movements and efferent tension.