Driving Simulation: How Low Can You Go?

This paper describes how older and cognitively impaired drivers perform worse in driving simulators as cognitive function declines. How realistic must driving simulations be to discriminate different categories of impaired drivers? High-end, high-fidelity, immersive simulators are expensive and unsuited for general use, whereas standardized neuropsychological (i.e. paper and pencil) tests have had mixed success in predicting driver fitness. Consequently, the authors designed a low-cost, PC-based, abstract virtual environment (VE) for assessing cognitively impaired drivers. Instead of striving for visual realism, the VE provides abstract representations of necessary visual cues in a single screen. The VE captures key elements of real-time driving in driving-like scenarios generated with flexible, usable, and cost effective PC software. This software comprises a suite of tools for testing cognitive functions engaged by driving tasks, such Go No-Go decision making and the ability to ignore irrelevant driving distracters mudsplashes. Pilot studies in several dozen subjects show that the VE tools discriminate between drivers with neurocognitive disorders (e.g, Alzheimer's disease, executive dysfunction from frontal lobe lesions) and older comparison drivers without cognitive impairment. Moreover, no drivers showed simulator adaptation syndrome or dropped out of pilot studies due to discomfort. The authors are comparing VE task performances with real world driving outcomes.