Figure 5. A) Proportion of synchrony judgments per group as a function of stimulus onset asynchrony (SOA), relative to the modality order of the preceding trial (collapsed across congruency conditions). Here, negative SOAs indicate that the voice was leading the lip movements, and vice versa. B) Point of subjective simultaneity (PSS) per group relative to the modality order on the preceding trial. C) Magnitude of recalibration effect (i.e., change in PSS between preceding modality orders) per group relative to age (in bins of 10 years). The error-bars reflect the standard error of the mean.
We conducted a repeated measures ANOVA on the mean PSS with previous modality order as a within subjects variable, group as a between subjects variable, and age as a covariate. We found a significant main effect of modality order (F (1,865)=13.823,p <.001), such that the PSS was smaller when audition led in the previous trial than when vision led, as Figure 5b illustrates. Rapid temporal recalibration did not differ between groups, as the modality order x group interaction failed to reach significance (F (1,865)=1.968, p =.161). Autistic participants showed a larger average PSS (240 ms) than non-autistic participants (190 ms) overall (F (1,865)=13.866, p <.001), reflecting a preference for a greater visual lead. Age did not significantly affect the magnitude of rapid temporal recalibration, as it did not interact with previous modality order (F (1,865)=2.624, p =.106; see Figure 5c). However, older participants did have a higher overall PSS (F (1,865)=51.770, p <.001). The mean PSS for participants above the median age was 249 ms, compared to a mean of 188 ms for those below the median age.