The trail making test: A study in focal lesion patients

The relationship of the Trail Making Test (TMT) to the frontal lobes was te sted by comparing patients,;vith damage to the frontal and nonfrontal regio ns to control participants. Although the analysis of time measurements, bot h raw and transformed, showed notable slowing of frontal groups, error anal ysis proved to be a more useful method of categorizing performance. Analysi s of errors on Part B indicated that all patients who made more than 1 erro r had frontal lesions. Dividing the frontal damaged patients into subgroups on the basis of the number of errors yielded specificity of brain-behavior relations within the frontal lobes. Patients with damage in dorsolateral f rontal areas were most impaired. Those with inferior medial damage to the f rontal lobes were not significantly affected in TMT Part B performance.