The Trail Making Test (part B) is associated with working memory: A concurrent validity study

The Test Making Test (TMT) was originally created as a distributed attention test. Part B (TMT-B) has been proposed as representative of executive functions as effective problem solving and working memory. This study aimed to explore the validity of the TMT-B as an indicator of working memory in adults. A cross-sectional study was conducted by using linear correlation coefficients between the TMT-B and neuropsychological and electrophysiological tests of working memory. Fifty-six individuals participated, all of which had normal cognitive functioning and were aged between 19 and 55 years old. Results show a significant correlation among the TMT-B scores with all subtests, the overall score of the Corsi Block-Tapping Test, the Working Memory Index of the WAIS-IV (Wechsler Adult Intelligence Scale) (p ≤ .05) and the auditory Event Related Potentials (p < .01) with the N200 and P300 latencies and amplitudes. These findings are preliminary evidence of the validity of the TMT-B for the evaluation of working memory in adults. Additional studies are required to assess the differential validity of the TMT-B in the evaluation of working memory, through comparative correlational analyzes with the results of various neuropsychological tests that assess other cognitive functions.