“Motion detection on flashed, stationary pedestal gratings: evidence for an opponent-motion mechanism” [Vision Research, 38 (1998) 795–812]

Fig. 3. Contrast thresholds for direction discrimination as a function of pedestal contrast (measured as in Fig. 1) at 7.43 and 15 Hz. The moving test was presented in 0 or 180° spatial phase with the pedestal (specified at middle of motion). The dashed line in each panel shows the mean threshold of the observers measured without the pedestal. Pedestals of 2–3% contrast produce the greatest facilitation with the 0° pedestal. At higher pedestal contrast, the direction threshold rises approximately following Weber’s law.