Figure 4.

Increased effect of viewing duration on V1 response in ASD. Like the middle temporal area, the primary visual area of the brain, V1, evidenced a severely attenuated response at short, as compared to long, viewing durations in ASD, as compared to controls. This finding mirrors our behavioural finding of an increased effect of viewing duration on behavioural performance in ASD, and suggests that global motion perception deficits in autism are reflected as early as primary visual cortex. (A) Mean tent function estimates of the time course of V1 response to each trial, averaged across all coherences and individuals, are plotted for illustration. (B) V1 magnitude was markedly affected by viewing duration in ASD, resulting in a significant interaction between Stimulus Duration and Diagnosis. Here, beta values estimated by a standard generalized linear model are plotted for each group and duration, averaged across all coherences and individuals. (C) V1 magnitude strongly correlates with accuracy. TRs = repetition times. In all plots, error bars represent 1 SEM. *P < 0.05, difference between the two groups.