Figure 3.

Motion discrimination performance and spatial summation strength at low contrast. A, Comparison of duration thresholds for discriminating low-contrast motion in participants with ASD and TD. Unlike high-contrast results, there are no substantial differences between groups except an increase in the TD (but not ASD) thresholds for the largest stimulus size (shown by the arrow). The insert shows data for participants who completed both low- and high-contrast experiments. B, Suppression index scores were negative for both groups, indicating spatial summation at low contrast. However, participants with TD also exhibited signs of spatial suppression (A, arrow). This was evident as a significant difference in suppression index score between the two groups. Error bars in both panels represent SEM.