Slowed Driving Reaction Time in Preclinical Alzheimer's Disease

Driving reaction time (DRT) is one of the most important predictors of motor vehicle crashes in older adults. Although individuals with preclinical Alzheimer's disease (AD) show subtle cognitive changes that may affect driving, their DRT to emergency events has not been investigated. We compared DRT to an emergency event between 19 drivers with preclinical AD and 21 controls in a driving simulator. All drivers engaged in a car-following task with and without distracters. After the car-following event, a crash prompted participants to brake and maneuver around the accident scene. Drivers with preclinical AD took longer to respond to the emergency event compared to controls when they were not distracted by an additional task (7.56 ± 1.46 s v 6.42 ± 1.17 s; p = .02). There were no group differences when a distraction was added to the car-following task. These pilot results have important implications on driving safety for older adults with preclinical AD when confirmed in larger on-road studies.