Objective: This study aimed to examine the impact of walking task complexity and cognitive speaking task (CST) condition on dual-task effects (DTE) in people with Parkinson’s disease (PwPD) and healthy older adults (HOA).

Background: PwPD often have difficulty performing a dual-task (DT), affecting both function and quality of life.  However, the influence of task complexity on DT performance is unclear.

Method: Data included 41 PwPD and 11 HOA [table1]. Participants completed two gait tasks—straight line walking (simple) and figure-8 walking with obstacle crossing (complex)—on a pressure-sensitive walkway, while performing four CSTs: oral trail making test (OT), counting, diadochokinetic (DDK), and spontaneous speech. Gait parameters (enhanced gait variability index (eGVI), step length, velocity) and response rate from CSTs were collected. DT metrics, including motor DTE (mDTE), cognitive DTE (cogDTE), combined DTE (cDTE), and modified attention allocation index (mAAI), were calculated. A 2×4 repeated measures ANOVA examined the effects of walking task complexity and speaking task condition on each DT metric.

Results: The type of CST significantly affected mDTE across gait measures in PwPD (ps<0.01), but not HOA. Gait complexity influenced mDTE for step length and velocity in PwPD (ps<0.01), and in velocity and egvi in HOA (ps<0.01). A significant interaction between gait complexity and CST was found for cogDTE in PwPD (p=0.01), but not HOA. For cDTE, significant effects of the CST were observed for step length and velocity in HOA (ps<0.04), but not in PwPD. The interaction between gait complexity and CST was significant in PwPD for mAAI (ps<0.01). mAAI was significantly affected by CST across gait measures in both groups (ps<0.026), and by gait complexity for step length and velocity in PwPD (ps<0.02) and eGVI in HOA (p=0.02). Post hoc contrasts revealed significant effects of the OT task on mAAI across gait measures in PwPD (ps<0.02) [figure1].

Conclusion: The results indicate that in PwPD, neither the CST nor complexity of a DT affects cDTE, suggesting it is a stable measure of DT capacity. Notably, the significant interaction effect on mAAI was seen only in PwPD, with the OT task showing a significant difference between simple and complex gait conditions. This suggests that more challenging CSTs shift prioritization during simple gait, but walking remains prioritized during complex gait.

figure1

table1

« Back to 2025 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/examining-the-influence-of-task-complexity-on-dual-task-performance-in-parkinsons-disease/