The purpose of this study was to examine the relationships between performances on standardized neuropsychological measures of cognitive abilities,simulated driving performance, and state crash records in drivers with cognitive decline due to aging and dementia. Participants were 202 experienced older adult drivers ages 55 years and older: 70 had mild dementia due to probable early Alzheimer's disease and 132 had no neurologic disease. All completed a battery of neuropsychological tests and drove contemporaneously on a high fidelity simulator. The participants' State Department of Transportation driving records were monitored for up to two years after testing. The simulator composite score, reflecting overall driving ability, was significantly correlated with overall cognitive ability, as indexed by the neuropsychology composite score, as well as with individual cognitive tests of attention, memory, visuospatial and visuomotor abilities. Drivers who crashed during an intersection incursion scenario performed significantly worse on the composite measure of cognitive function than those who successfully steered around the incurring vehicle. Crashers had specific cognitive deficits on measures of visuomotor abilities and attention. Memory test performances for both verbal information and visual material were associated with subsequent on-road crashes. These findings provide support for the validity of driving simulation as a safe means of evaluating a rangeof driving responses that cannot be tested on the road, and suggest that relatively simple and inexpensive neuropsychological tests of specific cognitive abilities could be used to help evaluate older drivers' risk of unsafe driving.
Abstract