Fig. 2.

Bayesian networks for executive functioning (executive), psychomotor speed (speed), and verbal memory (memory). Bayesian network analyses were used to analyze the conditional dependencies between FA/MD in 18 white matter tracts, age, sex, and education as potential determinants, and executive functioning, psychomotor speed, and verbal memory as outcome variables. Variables that are directly connected to one of the cognitive domains are identified as direct determinants. Variables that are connected indirectly to the cognitive domains (via other variables) are conditionally independent. As such, this method separates determinants with a direct deterministic influence on the outcome variable from other determinants that, although showing a univariate correlation with the outcome variable, have only an indirect influence when taking the direct determinants into account. Percentages indicate the confidence level of the arcs towards cognitive domains determined by 100 bootstrap replications. L, left; R, right.