Fig. 3.

Effect of changing luminance of the dimmer target on the initiation of pursuit. Each arrow represents an eye acceleration vector for the first 50-ms pursuit, where angle shows the direction of the eye acceleration and length shows the amplitude of the eye acceleration. Different colors indicate different luminance ratios, where the brighter target always had the same luminance. Top and bottom: data for monkeys G and P, respectively; to allow enough repetitions of each stimulus pair, we used only 2 pairs of orthogonal directions in each monkey. A and D: superimposed stimuli. B and E: stimuli presented 3° eccentric along orthogonal axes. C and F: stimuli presented 6° eccentric along orthogonal axes.