Differences in cortical activation characteristics between younger and older adults during single/dual-tasks: A cross-sectional study based on fNIRS

Abstract

Background

Aging-related decline in multitasking abilities increases the risk of falls, particularly during cognitive-balance dual-tasks. Previous studies have predominantly focused on cognition and balance performance, neglecting research on cortical activation related to balance. The study aims to explore differences in homeostatic control and cortical activation under different sensory conditions during single-tasks (STs) and dual-tasks (DTs) in older and younger adults.

Methods

20 elderly and 19 young participants completed balance STs and cognitive-balance DTs. Balance was assessed using an improved Clinical Test of Sensory Interaction on Balance (mCTSIB), while the cognitive task involved a “subtract 7 countdown.” Functional near-infrared spectroscopy (fNIRS) monitored activation in the left and right sensorimotor cortex, premotor cortex, and prefrontal cortex. Diverse sensory conditions, including restrictions on visual and proprioceptive inputs, were systematically incorporated into the experimental design.

Results

Older adults exhibited lower balance performance under DTs compared to STs when only vision was impaired. However, when both vision and proprioception were simultaneously impaired, the opposite was observed. Analysis of brain activation revealed a broader activation pattern in the older group during DT conditions compared to the younger group.

Conclusion

Older adults adopted a “posture-first” strategy for balance control during DT to prevent falls. In terms of cortical activation, the older group showing a more extensive pattern, suggesting a potential compensatory mechanism. Our findings provide a theoretical basis for reducing fall risk in the elderly through dual-task training and Cortical intervention.

Trial registration: The study was registered in the Chinese Clinical Trial Registry (ChiCTR2300078779) on 18 December 2023.