Cognitive-motor interference in post-stroke individuals and healthy adults under different cognitive load and task prioritization conditions

[Purpose] We aimed to compare the effects of cognitive load and task prioritization on dual task strategies in patients with stroke and healthy adults in order to clarify the characteristics of cognitive-motor interference. [Participants and Methods] In total, 26 patients with stroke and 26 age-matched healthy adults (controls) performed the Timed Up and Go Test while performing a serial subtraction task from random numbers between 90 and 100. Dual task was measured under four conditions in which two difficulty levels of “3 subtraction” and “7 subtraction” were multiplied by two prioritizing tasks that involved “paying equal attention to both walking and subtraction tasks” (no priority) and “paying attention while mainly focusing on subtraction tasks” (cognitive priority). [Results] Increasing cognitive load and prioritizing cognitive tasks affected motor performance in terms of the amount of time and number of steps required to complete the Timed Up and Go Test in both the patients and controls. However, cognitive load and task prioritization did not affect cognitive performance. [Conclusion] When cognitive load increases and instructions are given to prioritize increases in cognitive load, patients with stroke use the “posture first” strategy to stabilize their gait as effectively as healthy adults do.