The Impact of Task Difficulty on Driving Performance in Preclinical Alzheimer's Disease (AD): A Pilot Study

Abstract

<h3>Research Objectives</h3> To examine the impact of task difficulty on driving performance in preclinical Alzheimer's Disease (AD). We hypothesized that performance on driving simulator tasks will discriminate between drivers with preclinical AD and controls. <h3>Design</h3> A cross-sectional, observational study. <h3>Setting</h3> University of Kansas Medical Center. <h3>Participants</h3> Twenty participants (14 women) were included: 10 with preclinical AD [age 73.6±5] and 10 controls without preclinical AD [age 74.9±6.5], matched for age, sex, and cognitive status. <h3>Interventions</h3> Not applicable. <h3>Main Outcome Measures</h3> Participants completed a cognitively demanding car following task with and without a dual task in a semi-immersive virtual reality driving simulator. The 2-back test was used as the dual-task test. Standard deviation of lateral position (SDLP) and speed (SDS) were the primary outcomes of lateral and longitudinal vehicle control, respectively. Two-way ANOVA were employed to investigate main effects of task complexity (single versus dual task) and group (preclinical AD vs controls). <h3>Results</h3> Both groups showed significant increase in SDLP when engaged in a dual task (p = 0.001). SDLP increased from (mean ± SD in feet) 0.50 ± 0.30 in single task to 0.70 ±0.40 in dual-task conditions in preclinical AD group. SDLP increased from 0.55 ±0.33 in single task to 0.88 ±0.34 in dual-task conditions in controls. No other within or between group effects were observed. <h3>Conclusions</h3> While the measure of lateral vehicle control (SDLP) showed to be sensitive to task complexity, the measure of speed (SDS) showed less sensitivity. Neither measure discriminated between drivers with preclinical AD and controls. A better powered study with more participants may show more meaningful findings. <h3>Author(s) Disclosures</h3> Any conflict of interest will be disclosed by coauthors. I, Pedram Ahmadnezhad (author) do not have any conflicts of interest.