Using a Driving Simulator to Create a Visual Search Test for Drivers with Parkinson\u27s Disease

Visual search has been reported as one of the most important determinants of on-road driving in Parkinson’s disease (PD). Yet, commonly used visual search tests are administered on paper or on a computer and have no to little face validity. This study aimed to (1) create a visual search test in a driving simulator; (2) investigate the convergent validity of the test against the dot cancellation (DC) test; and (3) compare performance on the test between 20 drivers with PD and 15 controls. Participants searched for a target road sign among a clutter of other road signs on three screens with 100° of horizontal visual field. Drivers with PD took longer to respond (9s ± 2 vs 7s ± 1; p = 0.001) and missed more target road signs (1.50 (0.5 – 7) vs 0 (0 – 1); p = 0.01) than controls. No differences were found between groups on the DC test. Response time on the visual search test correlated strongly with DC time (r = 0.52; p = 0.009) and moderately with DC errors (r = 0.37; p = 0.03). Missed responses correlated moderately with DC time (r = 0.49; p = 0.02). Our findings suggest that the driving simulator visual search test offers a valid alternative to standard visual search tests. Future research is needed to investigate the validity of the new visual search test in predicting on-road driving performance in PD