Fluid ability, Model B.

Notes: Hemi: hemisphere, Measure: (T)hickness or (V)olume, a: parameter relating age group to brain measure, c’: parameter relating age group to cognitive measure, b: parameter relating brain measure to cognitive measure, q: parameter relating lifetime exposure (LE) to cognitive measure, v: interaction of brain measure and LE in predicting cognitive measure. The last seven columns are the indirect effects of age group on the cognitive measure via the brain measure probed at percentiles of LE. **significant at p(FDR) <0.05; *significant at p(uncorrected) <0.05.