Fig. 1

Main effect of sex: local cortical volume. a Whole-brain analyses (p < 0.01, corrected). In each hemisphere, one cluster at the pSTG/PT showed a relative increase in cortical volume in females compared to males, both within each diagnostic group (black signs) and across diagnostic groups (gray signs). For the post-hoc two-by-two analyses, the following p values are depicted: *p < 0.05, **p < 0.01, ***p < 0.001. b Bootstrapping analyses. The likelihood to observe both clusters was tested using a bootstrap procedure, simulating sample sizes ranging from 15 to 50 individuals in each group (total n = 60–200). For a sample size of 30 females with ASD, the probability to observe the pSTG/PT clusters at the level of p < 0.05 (corrected) was below 40 % for the right hemisphere and below 60 % for the left hemisphere. c Power analyses. Plot depicting the relationship between statistical power and sample size, computed a posteriori based on the effect sizes obtain in the full dataset