Performance and Workload Trends: The Effects of Repeated Exposure to “High” Demand Tasks

Abstract

The N-back and Surrogate Reference Task (SuRT) are frequently used to evaluate the workload potential of secondary driving tasks as high cognitive and visual demand benchmarks. This paper examines the effect of repeated exposures to the N-back and SuRT reference tasks, and any resulting change in task performance or workload that may negate their effectiveness as calibration tools and high workload benchmarks. One-way repeated measures ANOVA analyses demonstrate that N-back performance improves while workload decreases, suggesting limitations in methodology for measuring task workload after multiple exposures. Alternatively, SuRT performance improves while workload remains relatively stable, indicating the task elicits a constant visual demand despite performance improvements. This paper discusses the limitations of the N-back and SuRT as reference tasks in workload and driving research, and proposes future directions to further clarify their use.