Attentional demands of perturbation evoked compensatory stepping responses: examining cognitive-motor interference to large magnitude forward perturbations.

The authors examined the cognitive-motor interference of reactive balance control under dual-task condition in young healthy adults. Sudden large forward perturbations were delivered in stance position with (dual-task) and without (single-task balance) a working memory task. This task was also performed in quiet stance (single-task cognition). Dual tasking significantly reduced postural stability and compensatory step length, and delayed the reaction time. The significant linear correlation between postural stability and compensatory step length present in the single-task balance condition was absent in the dual-task condition. Performance on the cognitive task also declined under the dual-task condition. Our results indicate a mutual cognitive-motor interference between the reactive balance and the working memory task suggesting a potential overlap between attentional resources allocated for these two tasks.