The Impact of Eye Movements and Cognitive Workload on Lateral Position Variability in Driving

Objective: The objective of this work was to understand the relationship between eye movements and cognitive workload in maintaining lane position while driving. Background: Recent findings in driving research have found that, paradoxically, increases in cognitive workload decrease lateral position variability. If people drive where they look and drivers look more centrally with increased cognitive workload, then one could explain the decreases in lateral position variability as a result of changes in lateral eye movements. In contrast, it is also possible that cognitive workload brings about these patterns regardless of changes in eye movements. Method: We conducted three experiments involving a fixed-base driving simulator to independently manipulate eye movements and cognitive workload. Results: Results indicated that eye movements played a modest role in lateral position variability, whereas cognitive workload played a much more substantial role. Conclusions: Increases in cognitive workload decrease lane position variability independently from eye movements. These findings are discussed in terms of hierarchical control theory. Applications: These findings could potentially be used to identify periods of high cognitive workload during driving.