Visual Search of Road Signs In Parkinson’s Disease: A Pilot Study

Abstract

Objective: To (1) compare visual search of road signs between patients with Parkinson's disease (PD) and control volunteers and (2) explore cognitive workload and cognitive functions related to visual search. Design: Prospective study. Setting: Augusta University Simulator Lab. Participants: 18 patients with PD and 10 controls. Interventions: Not applicable. Main Outcomes Measures: Correct response time (cRT) for the visual search task. Participants were asked to search a pre-identified road sign (target) within 15 seconds. The target was present in half of the 42 trials. Cognitive workload, indexed by task-evoked pupillary response, was recorded during the visual search task. Participants also completed the Montreal Cognitive Assessment, Trail Making Test, Useful Field of View, Figure of Rey, Stroop, and dot cancellation. Differences between groups in visual search cRTs and cognitive workload were calculated using t-tests. Associations between neuropsychological performances and visual search cRTs were calculated with Pearson correlations. Results: Patients took longer to complete the visual search task than controls (cRTpatients, s: 8.6±1.6 versus cRTcontrols: 7.3±1.4, p=0.03). No group differences in cognitive workload were observed. Significant correlations were found between all neuropsychological tests and cRTs of the visual search task in the PD group (p