Mediation models are presented for (A) FFA, (B) PrC, and (C) HC. These models test the extent to which the relationship between BOLD response (in the a priori FFA, PrC, and HC ROIs) and odd-one-out accuracy is mediated by WM microstructure. The left, middle, and right boxes in each model represent the independent variable (IV), mediator (M), and dependent variable (DV), respectively. Unstandardised coefficients and their corresponding one-tailed p values are depicted for each path of interest (a, b, a*b, c′, and c). In a simple mediation model, these paths reflect the following: path c represents the total effect of the IV on the DV; path a quantifies the effect of the IV on the M; path b reflects the causal effect of the M on the DV; and path c′ is the direct effect of the IV on the DV that also partials out the effect of the M. Significant paths are indicated by dashed lines and significant terms are indicated by bold font. The bootstrap 95% CI is displayed for the indirect effects (a*b). See Supplementary file 2 for further details.