An on-road assessment of the impact of cognitive workload on physiological arousal in young adult drivers

In this paper, we describe changes in heart rate and skin conductance that result from an artificial manipulation of driver cognitive workload during an on-road driving study. Cognitive workload was increased systematically through three levels of an auditory delayed digit recall (n-back) task. Results show that changes in heart rate and skin conductance with increasing levels of workload are similar to those observed in an earlier simulation study. Heart rate increased in a step-wise fashion through the first two increases in load and then showed a less marked increase at the highest task level. Skin conductance increased most dramatically during the first level of the cognitive task and then appeared to more rapidly approach a ceiling (leveling) than heart rate. Findings further demonstrate the applicability of physiological indices for detecting changes in driver workload