Attentional prioritization in dual-task walking: Effects of stroke, environment, and instructed focus.

BACKGROUND

The impact of high distraction, real-world environments on dual-task interference and flexibility of attentional prioritization during dual-task walking in people with stroke is unknown.

RESEARCH QUESTION

How does a real-world environment affect dual-task performance and flexible task prioritization during dual-task walking in adults with and without stroke?

METHODS

Adults with stroke (n = 29) as well as age-, gender-, and education-matched adults without stroke (n = 23) participated. Single and dual-task walking were examined in two different environments (lab hallway, hospital lobby). Two different dual-task combinations were assessed (Stroop-gait, speech-gait). Each dual-task was performed first without explicit instruction about task prioritization (no-priority) and then with gait-priority instruction and Stroop/speech-priority instruction in randomized order.

RESULTS

People with stroke had significantly slower dual-task gait speed (Stroop only) in the lobby than the lab, but the effect was not clinically meaningful. Stroop reaction time for all participants was also slower in the lobby than the lab. All participants slowed their walking speed while generating spontaneous speech, but this effect was not influenced by environment. The dual-task attention allocation strategy was generally inflexible to instructed prioritization in adults with and without stroke in both environments, however, the volitional attention allocation strategy differed for the two dual-task conditions such that speech was prioritized in the speech-gait dual-task and gait appeared to be prioritized in the Stroop-gait dual-task.

SIGNIFICANCE

Although dual-tasking slows walking speed and verbal responses to auditory stimuli in people with stroke, the effects are not considerably impacted by a more complex, distracting environment. Adults with and without stroke may have difficulty overriding the preferred attention allocation strategy during dual-task walking, especially for habitual dual-tasks such as walking while speaking. It may also be that the cognitive control strategy governing task prioritization is influenced by degree of cognitive engagement.