Experimental Framework for Simulators to Study Driver Cognitive Distraction: Brake Reaction Time in Different Levels of Arousal

摘要

Distraction has the potential to degrade driving performance and may have serious consequences for road safety. There is a number of research in this area and most studies concentrate on perception errors as a result of visual distraction, so much so that NHTSA has issued driver distraction guidelines to address visual and manual sources of distraction. Cognitive distraction occurs when attention is withdrawn from the processing of information necessary for the safe operation of a vehicle and seems to be qualitatively different from those associated with visual distraction.Among those sources of distraction, the cognitive one is the most difficult the to assess because of the problems associated with the observation of what a driver's brain, as opposed to hands or eyes is doing.Despite many published standards, that specify a number of methods for evaluating the visual and manual demand of secondary task interactions, there are currently no published standards that explicitly and exclusively apply to cognitive distraction. In this paper is presented an experimental framework, developed within DRIVE IN2 project (DRIVEr Monitoring: Technologies, Methodologies and IN-vehicle INnovative systems for a safe and eco-compatible driving), based on a driving simulator and car-following paradigm, with the lead vehicle that brakes suddenly when a driver in a loop system, that analyzes in real time EEG signals, detects boot very high and very low level of engagement or arousal. As driving simulator, also the Sim-Panda has been used, developed in the project, the first prototype for testing driver monitoring systems in safety conditions and in a real car.Neuro-feedback for controlling the lead vehicle is obtained by the SDK (Suite Development Kit) of Neuro-Headset Emotiv EPOC, that uses proprietary metrics, that looks for distinct brainwave characteristics that are universal in nature and do not require signature-building or individual baselining. The first is “Engagement”, characterized by increases in beta and attenuated alpha waves, and the other is “Excitement”, associated with arousal and overall physiological response.To study cognitive driver distraction, reaction time is evaluated, measuring time elapsed between sudden braking lead vehicle and response from drivers. Results are interpreted comparing brake reaction time recorded when the two metrics are booth above or below specific thresholds, obtaining indications of a driver's ability to quickly and safely respond to the sudden appearance of a threat.Reaction time measures show a great deal of consistency, and our preliminary results report that drivers responses to a lead braking vehicle are the slower, the higher is the attention they are paying to the roadway, as the drivers that are engaged in secondary-vehicle activities.