EFFECTS OF DIFFERENT VISUAL ATTENTION TASKS ON OBSTACLE CROSSING IN HEALTHY YOUNG ADULTS

Dual-task obstacle crossing gait paradigms are commonly adopted to examine how attentional demands are associated with sensory-motor processing during obstacle crossing. Various attention tasks have been used with mixed findings. This raises a question whether and how different attention tasks would affect motor function differently. Therefore, we examined and compared the effects of two visual attention tasks on obstacle crossing in healthy young adults. In the first experiment, 10 young adults responded to a 200 ms visuospatial attention task during the approaching phase of obstacle crossing. In the second experiment, another 10 young adults responded to a visual Stroop task while approaching and crossing an obstacle. In both experiments, subjects completed an obstacle crossing only, a visual attention only, or a dual-task obstacle crossing condition in a random order. Dual-task costs were calculated for each visual attention task on the accuracy rates, toe-obstacle clearances and gait velocities. Two tripping incidences occurred only in the dual-task condition with visuospital attention task. Trailing toe-obstacle clearance reduced in the dual-task condition with visuospital attention task, but toe-obstacle clearances of both limbs increased in the dual-task condition with Stroop task. Gait velocities were not affected by the visuospatial attention task but were significantly reduced when concurrently performing the Stroop task. Dual-task costs were significantly different between two experiments on the gait velocity and toe clearances, but not on the accuracy rate. Our findings demonstrated that different visual attention tasks lead to distinct modifications on obstacle crossing behaviors.