11 NASA-TLX Workload Profile of the Trail Making Test

Objective:Workload is a useful construct in human factors and neuroergonomics research that describes “the perceived relationship between the amount of mental [and physical] processing capability or resources and the amount required by the task”. We apply this concept to neuropsychology and assess several dimensions of workload as it relates to performance on the Trail Making Test.Participants and Methods:Twenty college students completed the Trail Making Test (TMT). After completion of each Part A and B, workload was assessed with the NASA-Task Load Index (NASA-TLX), a popular self-report measure of workload including subscales: Mental Demand, Physical Demand, Temporal Demand, Performance, Effort, and Frustration, with an overall average total score as well.Results:Completion time differed of course between Parts A and B (p textless .001). Of more interest, overall workload differed between TMT A (M = 20.33, SD = 13.32) and TMT B (M = 35.79, SD = 17.37) (p textless .001, h2 = .68). The greatest subscale differences were with Mental Demand (p textless .001, h2 = .68) and Effort (p textless .001, h2 = .59), but Physical Demand also showed a difference (p textless .007, h2 = .33). Temporal Demand showed the smallest and nonsignificant difference (p = .081, h2 = .152).Conclusions:Based on previous research in our lab, most results were expected and understandable. As we know with the TMT, Part B is more cognitively demanding (in various ways) than Part A. The greater Physical Demand with Part B is a somewhat more complex finding, needing a solid explanation. Finally, the NASA-TLX appears to be a valid instrument of workload with a standard neuropsychologist test. We argue it can provide useful interesting information in the assessment of cognitive status in clinical populations.