Fig. 3: Individual differences in between-hemisphere functional distance mediate the effect of brain size on fluid intelligence.
From: Functional divergence between the two cerebral hemispheres contributes to human fluid intelligence
a We observed significant correlations between brain size, global between-hemisphere functional distance, and fluid intelligence after controlling for age, sex, handedness, and mean framewise displacement. We tested the significance of the hypothetical mediation pathway, in which global between-hemisphere functional distance could partially mediate the impact of brain size on fluid intelligence. Significance was tested by bootstrapping (10,000 replacements). The shaded region around each line indicates the 95% CI. b A GLM analysis was performed on vertexwise between-hemisphere functional distances to identify regions associated with intelligence, in which age, sex, handedness, brain size, and mean FD were included as covariates. The resultant t maps for fluid intelligence are shown. The regions with gray outlines were significant vertices after FDR correction (one-tailed pFDR < 0.05). c The mean between-hemisphere functional distances within a mask consists of all significant vertices also exhibited a significant mediating effect on the relationship between brain size and fluid intelligence.
