In understanding how distraction changes our driving habits, it's the little things that count. Researchers Bryan Reimer and Bruce Mehler of the AgeLab and New England University Transportation Center have conducted research on the relationship between physiological arousal, visual behavior and secondary cognitive workload during driving. By measuring heart rate and skin conductance, they found a statistically significant increase across 4 levels of workload.
Despite age and gender differences in base levels of physiological activity, the overall pattern of incremental change in heart rate and skin conductance in response to increased cognitive demand was consistent all ages and both genders. Gaze centralization varied by task difficulty as well, and appeared predominantly in the horizontal plane, unrelated to age.
The results increase the confidence with which these measures can be utilized as indicators of subtle differences in cognitive load.
The relevant papers, listed below, were presented at the 54th Annual Meeting of the Human Factors and Ergonomics Society and appear in the Proceedings:
Reimer, B., Mehler, B., Wang, Y., Coughlin, J. (2010) The Impact of Systematic Variation of Cognitive Demand on Drivers' Visual Attention across Multiple Age Groups. Proceedings of the 54th Annual Meeting of the Human Factors and Ergonomics Society, San Francisco. (pdf)
Mehler, B., Reimer, B., Coughlin, J. (2010) Physiological Reactivity to Graded Levels of Cognitive Workload across Three Age Groups: An On-Road Evaluation. Proceedings of the 54th Annual Meeting of the Human Factors and Ergonomics Society, San Francisco. (pdf)