The apparent path of a stationary and a circularly moving spot during the smooth pursuit of another circularly moving spot.

The apparent movement path (AMP) of a circularly moving spot pursued by the eyes (spot A) and of another stationary or circularly moving spot (spot B) were examined. Experimental variables were speed of rotation; number of rotations; position of the stationary spot (experiment) 1) and phase angle between rotation of spot A and B (experiment 2). The AMP of spot A was a spirally shrinking circular or elliptic path Both speed and number of rotations had an effect on the size of AMP of spot A. The AMP of spot B was in general a circle or an ellipse in some respects corresponding with the retinal locus of the image of spot B.