The analyses revealed that the IQ groups did not differ in global mean of FA, RD, and AD. There were neither significant group mean differences for IQ group (FA: F(1, 59) = .28, ns;. RD: F(1, 59) = .00, ns;. AD: F(1, 59) = 3.24, ns) nor for sex (FA: F(1, 59) = 1.50,

ns;. RD: F(1, 59) = 2.45, ns; AD: F(1, 59) = 2.86, ns), nor a significant interaction (FA: F(1, 59) = .95, ns;. RD: F(1, 59) = .68, ns; AD: F(1, 59) = .22, ns). Explorative voxel-wise TBSS analyses of sex differences revealed no significant differences in FA values between women and men. A similar explorative analysis testing intelligence group differences and the two-way interaction IQ group∗sex was also not significant. In order to examine a

potentially moderating effect of sex on the intelligence-FA relationship, analyses GSK2118436 solubility dmso with the predictor intelligence were run separately for sex groups. The results indicated that less and more intelligent women did not differ in FA, but we discovered intelligence group differences for men in regional microstructural white matter. As shown in Fig. 1, more intelligent men showed higher FA compared Ibrutinib molecular weight to less intelligent men in the genu of the corpus callosum (CC) bilaterally and higher FA values in the body of the right CC relative to the global FA (p < .05, FWE corrected; see Table 2). In Table 3, mean as well as standard deviations for each group in each region are presented. Additionally effect sizes are reported.

Radial diffusivity, the potential marker of myelination, was lower in more intelligent men as compared to less intelligent men in the areas of altered FA in the genu of the CC bilaterally relative to the global RD (p < .05, FWE corrected, see Table 2). All other group comparisons (differences in RD between IQ groups, differences in RD between women and men, the interaction IQ group∗sex and differences in RD between less and more intelligent women) did not yield significant differences. Also, no significant effects emerged with respect to axial diffusivity, the potential marker of axonal integrity. This study aimed at examining sex and intelligence differences in the white matter 17-DMAG (Alvespimycin) HCl microstructure. Our study was based on research demonstrating that the relationship of intelligence and brain structure may differ between the sexes (Tang et al., 2010), even when there are no general ability differences (Deary et al., 2007 and Dykiert et al., 2009). In this study, the relationship of intelligence and WM microstructure was found to differ between the sexes: Intelligence-dependent white matter differences were only observed for men. Specifically, our analyses indicated that more intelligent men showed higher FA in the genu of the corpus callosum (CC) bilaterally and in the right body of the CC than less intelligent men.