弹力带抗阻运动对高龄老年人工作记忆的影响——来自fNIRS的证据

Effects of Elastic Band Resistance Exercise on the Working Memory in the Aged People: Evidence from fNIRS

目的观察长期弹力带运动改善高龄老年人工作记忆的效果,采用近红外光谱技术探究可能的脑机制。方法将60名高龄老年人随机分为弹力带组与对照组,弹力带组接受16周、每周3次、每次40 min的弹力带干预,对照组保持原有生活状态;采集实验前后受试者完成工作记忆任务期间的前额叶血流动力学指标。结果反应时的时间×组别交互效应具有统计学意义(P<0.001);正确率的时间×记忆负荷交互效应具有统计学意义(P=0.003);正确反应率的时间×组别交互效应具有统计学意义(P<0.001);氧合血红蛋白结果显示,9条通道组别×时间×记忆负荷交互效应均具有统计学意义(P<0.002)。结论规律性中低强度弹力带抗阻运动能改善高龄老年人的工作记忆表现;在低记忆负荷时前额叶激活不明显,中、高记忆负荷时双侧腹外侧前额叶、左背外侧前额叶、左额极区显著激活,这种前额叶激活优化模式可能是弹力带抗阻运动改善工作记忆的脑机制。

Objective To examine the effect of elastic band exercise in improving the working memory in aged people,and to explore the potential brain mechanism by functional Near Infrared Spectroscopy(fNIRS).Methods Sixty aged people were randomly divided into an elastic band group(EBG)and a control group(CG).EBG received elastic band intervention for 16 weeks,3 times a week,40 minutes each time,and CG maintained the original living condition.The subjects'prefrontal cortex hemodynamics during the N-back task were measured before and after the intervention.Results The time×group interaction of reaction time(RT)was statistically significant(P<0.001).The interaction effect of time×working memory load at accuracy was statistically significant(P=0.003).The interaction effect of time×group at rate-correct score was statistically significant(P<0.001).The results of HbO2 showed that the interaction effect groups×time×working memory load was statistically significant in 9 channels(P<0.002).Conclusion Regular low-to-morderate-intensity elastic band resistance exercise improved the working memory performance in aged people.The activation of the prefrontal cortex was not significant at low working memory loads,and the activity of the bilateral ventrolateral prefrontal cortex,left dorsolateral prefrontal cortex and left frontopolar cortex area were increased at medium and high memory loads.This optimized prefrontal cortex activation pattern may be the brain mechanism by which resistance exercise improves working memory.