Slowed Driving Reaction Time in Preclinical Alzheimer's Disease

Area of Science:

• Neuroscience
• Gerontology
• Transportation Safety

Background:

• Driving reaction time (DRT) is crucial for older adult safety.
• Preclinical Alzheimer's disease (AD) involves subtle cognitive changes potentially affecting driving.
• DRT to emergency events in preclinical AD has not been studied.

Purpose of the Study:

• To investigate DRT to emergency events in individuals with preclinical AD compared to controls.
• To assess the impact of cognitive load (distractions) on DRT in preclinical AD.

Main Methods:

• A driving simulator study compared 19 drivers with preclinical AD and 21 controls.
• Participants performed a car-following task with and without distracters.
• An emergency event (simulated crash) required participants to brake and maneuver.

Main Results:

• Drivers with preclinical AD exhibited significantly longer DRT (7.56 ± 1.46 s) than controls (6.42 ± 1.17 s) during non-distracted driving (p = .02).
• No significant group differences in DRT were observed when an additional task (distraction) was introduced.
• These pilot results suggest a specific vulnerability in non-distracted driving scenarios.

Conclusions:

• Preclinical AD may impair driving reaction time to emergencies, particularly under low cognitive load.
• Driving safety implications for older adults with early-stage AD warrant further investigation in on-road studies.
• Future research should explore real-world driving performance and the role of cognitive load.