Effect of motor tasks with left monocular eyeglasses on visual search and line-bisection performance in people with left unilateral spatial neglect

Training with an eyepatch or eyeglasses is one of the effective approaches for unilateral spatial neglect (USN), and it usually uses a device that covers the right side. However, few approaches are available for the left side. In this study, we examine the effect of motor tasks with left/right monocular eyeglasses on visual search and line-bisection performance in people with left USN. Seven participants with left USN admitted to convalescent hospitals were included. We conducted the Bells test, line-crossing test, and line-bisection test of the behavioral inattention test before/after the motor task. Our analyses focused on the improvement or decline in these assessment scores and the achievement/errors/non-smoothness scores of the motor task. When using the left monocular eyeglasses, the percentages of participants categorized as "improvement," "unchanged," and "decline" were 71.4%, 28.6%, and 0%, respectively (when using the right one they were 14.3%, 85.7%, and 0%). In the motor task, when using the left monocular eyeglasses, total achievement scores in five of seven participants were greater than those when using the right one, and they performed efficiently with fewer movement errors. These results suggest that training with left monocular eyeglasses might improve visual search performance in people with left USN.