Cognitive correlates of cross-sectional differences and longitudinal changes in trail making performance.

A total of 1,576 adults between 18 and 95 years of age performed a battery of cognitive tests and the Connections version of the Trail Making Test twice, with an average interval between assessments of 2.5 years. Consistent with previous results, speed ability and fluid cognitive ability were strongly correlated with trail making performance. Neither speed nor fluid cognitive ability at the first occasion predicted longitudinal changes in trail making performance, but there were significant correlations between the changes in these abilities and the changes in trail making performance. These results indicate that individual differences in speed and fluid cognitive abilities are associated with individual differences in trail making performance both at a single point in time (cross-sectional differences) and in the changes over time (longitudinal changes).