Driving is a complex activity requiring good management of attentional resources, efficient cognitive control and decision-making. Numerous studies have sought to understand dual task interference, and in particular whether drivers have enough spare capacity to take on an additional task or whether the mental effort that demands results in driving task alteration. This study aims to analyse the relationship between mental effort and driving performance and to identify mental effort indicators from three different measurements recorded on a car simulator: cardiac activity, driving performance, and subjective data (DALI, Driving Activity Load Index). Three conditions have been designed to vary the driver’s mental effort: driving as the sole task (control situation), driving while solving two different cognitive tasks, resolution of verbal or visuo-spatial enigmas. Preliminary results show that although heart rate variability does not seem sensitive enough to reflect the mental effort in car simulator studies the HF/LF ratio could be used as an indicator of the participant’s investment in the task. In addition, the DALI seems useful for identifying the mental effort variation between the verbal and the visuo-spatial added tasks. Finally, the detection of mental effort from lane position variability seems encouraging. (Author/publisher)
Abstract