Effects of aging on efficiency of task switching in a variant of the trailmaking test

The Trail Making Test (TMT; R. M. Reitan, 1958, 1992) is extensively used i n research in neuropsychology and in aging, in part because it has been pos tulated to reflect executive processes, such as planning and switching. How ever, neurocognitive and individual-difference-based analyses of this test are complicated because of different spatial arrangements of targets, the u se of letters only in Version B, and potential order effects when Version A is administered prior to Version B. The present article examines a Variant of a TMT (called the Connections Test) that attempts to remedy these defic iencies. A structural equation model suggested that there were no direct ef fects of age on either the nonalternating or alternating Versions of the Co nnections Test (analogous to TMT Versions A and B, respectively); rather, a ll age-related effects were mediated through effects on perceptual speed. M oreover, although the nonalternating and alternating versions were strongly related to one another, only the latter had significant independent relati ons with measures of higher order cognition.