Figure 2

Motion coherence thresholds (measured as percentage of coherently moving dots at threshold) (+ SE) for all groups. The CA control group showed the best performance (lowest percentage of coherent dots) but did not differ significantly from performance of the DD group. Worst performance was seen for the chronologically youngest group, the RA controls, and no difference in performance was seen between the high and low intelligence control groups, suggesting chronological age is a better predictor of motion coherence threshold than reading ability or intelligence. (Symbols denotes significantly different from RA group, * p < .05; ** p < .01).