, FÁTIMA AZEVEDO IGNÁCIO 7 , ROGÉRIO PAYSANO MARROCOS 8 ABSTRACT -We tested the hypothesis that Part B of the Trail Making Test (TMT) is a measure of cognitive setshifting ability in 55 normal subjects with the conventional (written) TMT and a verbal adaptation, the "verbal TMT" (vTMT). The finding of a significant association between Parts B of TMT and vTMT (r = 0,59, p < 0,001), after correcting for age and education, supports the view that Part B of TMT is a valid measure of the ability to alternate between cognitive categories.KEY WORDS: trail making test, verbal trail making test, set-shifting cognition. . In Part A, the circles are numbered from 1 to 25, whereas in Part B numbers from 1 to 13 and letters from A to M must be connected in alternating fashion, beginning at 1-A and ending at M-13. Total score is given by time spent to complete each part. Factor analysis has shown that the TMT loads on both a rapid visual search and a visuospatial sequencing factor 3 . Whether it also superimposes on a third, "cognitive set-shifting", factor has been debated [4][5][6] . If true, however, this would be an important attribute of the test, as the ability to switch between categories is one of the most reliable indexes of normal neurobehavioral functioning 7 .In this study we administered a verbal adaptation of TMT-the "verbal Trail Making Test" (vTMT)-to normal individuals to see whether Part B of Trail Making Test (TMTB) also gauges the ability to shift between cognitive sets. Since in vTMT the visuospatial and visuomotor factors intrinsic to the conventional (written) TMT are reduced to a minimum, a lack of correlation between Parts B