Wang Guozheng, Yang Yi, Liu Xiaoxia, Hua Anke, Luo Xin, Cai Yiming, Song Yanhua, Wang Jian, Liu Jun
Department of Sports Science, College of Education, Zhejiang University, Hangzhou, 310058, PR China; Taizhou Key Laboratory of Medical Devices and Advanced Materials, Taizhou Institute of Zhejiang University, Taizhou, 318000, PR China.
Department of Sports Science, College of Education, Zhejiang University, Hangzhou, 310058, PR China; Department of Sports Science, School of General Education, Wenzhou Business College, Wenzhou, 325035, PR China.
Neuroimage. 2025 May 15;312:121218. doi: 10.1016/j.neuroimage.2025.121218. Epub 2025 Apr 14.
Balance control is crucial for stability during daily activities, relying on the integration of sensory inputs from the visual, vestibular, and somatosensory systems. Aging impairs the efficiency of these systems, leading to an increased risk of falls; however, the neural mechanisms underlying this decline, particularly under sensory conflict, are not fully understood. This study investigated the effects of aging on neural connectivity and sensory integration during balance tasks. Ninety-six participants (47 older adults and 49 young adults) were subjected to balance perturbation tasks under sensory-congruent and sensory-conflict conditions using a virtual reality headset and rotating platform. Behavioral measures, including postural sway and perceptual accuracy, were recorded. Electroencephalography (EEG) data were analyzed using generalized partial directed coherence (GPDC) to assess the directed functional connectivity and network efficiency. Older adults exhibited significantly greater postural sway, reduced perceptual accuracy, and a diminished ability to detect sensory conflicts than young adults, particularly under conflict conditions. As demonstrated by connectivity analysis, young adults showed adaptive shifts in connectivity from the visual to somatosensory regions during sensory conflict. In contrast, older adults demonstrated a less adaptable mode of connectivity. At the same time, global efficiency and clustering coefficients of young adults were higher, suggesting more effective and modular brain networks. Correlation analyses in older adults revealed that higher visual cortex efficiency was linked to lower postural sway specifically during sensory conflict, whereas higher motor cortex efficiency was associated with greater sway only under sensory-congruent conditions. In short, neural adaptability is vital in sensory integration and balance control. Due to decreased neural flexibility and network efficiency in older adults, their sensory reweighting was undermined and instability increased during the sensory conflict. These findings establish a foundation for development of targeted interventions to strengthen balance and lower the risks of falls in older adults.
平衡控制对于日常活动中的稳定性至关重要，它依赖于视觉、前庭和体感系统的感觉输入整合。衰老会损害这些系统的效率，导致跌倒风险增加；然而，这种下降背后的神经机制，尤其是在感觉冲突情况下，尚未完全了解。本研究调查了衰老对平衡任务期间神经连接和感觉整合的影响。96名参与者（47名老年人和49名年轻人）使用虚拟现实头戴设备和旋转平台，在感觉一致和感觉冲突条件下接受平衡扰动任务。记录了包括姿势摆动和感知准确性在内的行为指标。使用广义偏定向相干分析（GPDC）分析脑电图（EEG）数据，以评估定向功能连接和网络效率。老年人表现出明显更大的姿势摆动、更低的感知准确性，并且与年轻人相比，检测感觉冲突的能力下降，尤其是在冲突条件下。连接性分析表明，年轻人在感觉冲突期间显示出从视觉区域到体感区域的连接适应性转变。相比之下，老年人表现出适应性较差的连接模式。同时，年轻人的全局效率和聚类系数更高，表明大脑网络更有效且模块化。对老年人的相关性分析表明，更高的视觉皮层效率与感觉冲突期间更低的姿势摆动相关，而更高的运动皮层效率仅在感觉一致条件下与更大的摆动相关。简而言之，神经适应性在感觉整合和平衡控制中至关重要。由于老年人神经灵活性和网络效率下降，他们的感觉重新加权受到破坏，并且在感觉冲突期间不稳定性增加。这些发现为制定针对性干预措施以增强老年人平衡能力和降低跌倒风险奠定了基础。
