Virtual Reality-Based Navigation Task to Reveal Obstacle Avoidance Performance in Individuals With Visuospatial Neglect

Individuals with post-stroke visuospatial neglect (VSN) frequently collide with moving obstacles while walking. It is not well understood whether the collisions occur as a result of attentionalperceptual deficits caused by VSN or due to poststroke locomotor deficits. This study assessed individuals with VSN on a seated, joystick-driven obstacle avoidance task, thus eliminating the influence of locomotion. Twelve participants with VSN were tested on obstacle detection and obstacle avoidance tasks in a virtual environment that included three obstacles approaching head-on or 30° contralesionally/ ipsilesionally. In the detection task, the contralesional and head-on obstacles were detected at closer proximities compared to the ipsilesional obstacle. For the avoidance task collisions were observed only for the contralesional and head-on obstacle approaches. For the contralesional obstacle approach, participants initiated their avoidance strategies at smaller distances from the obstacle and maintained smaller minimum distances from the obstacles. The distance at detection exhibited a negative association with the distance at the onset of avoidance strategy for all three obstacle approaches.

The observation of collisions with contralesional and head-on obstacles, in the absence of locomotor burden, provides evidence that attentionalperceptual deficits due to VSN, independent of poststroke locomotor deficits, affect obstacle avoidance capabilities.