An on-road assessment of cognitive demand

Objective: This paper aims to understand the driving performance degradation and gaze dispersion changes under auditory cognitive workload conditions which consists of three different levels of cognitive complexity. Background: As the use of in-vehicle technologies became more popular, there is concern about a concomitant increase in driver distraction arising from their use. While the introduction of voice recognition systems is intended to reduce the distraction due to manual operation of these units, a significant proportion of the distraction associated with their use may arise not from the manual manipulation but rather the cognitive consequences. It is also known that the risk of inattentive driving varies with age. Method: In this study, 15 younger drivers (aged 25-35) engaged in three levels of a delayed auditory recall task, so called N-back task, while driving on a highway. Results: It was observed that gaze dispersion decreased with each level of demand, demonstrating that these indices can correctly rank order cognitive workload. Conclusion: Effects were also observed on driving performance measures including average speed and standard deviation of lane position, but they were subtle, nonlinear, and did not effectively differentiate. Application: The results of the publishing trend analysis might help to assess automotive human machine interface (HMI) design.