Table_1_Task-Switching Performance Improvements After Tai Chi Chuan Training Are Associated With Greater Prefrontal Activation in Older Adults.DOCX

Studies have shown that Tai Chi Chuan (TCC) training has benefits on task-switching ability. However, the neural correlates underlying the effects of TCC training on task-switching ability remain unclear. Using task-related functional magnetic resonance imaging (fMRI) with a numerical Stroop paradigm, we investigated changes of prefrontal brain activation and behavioral performance during task-switching before and after TCC training and examined the relationships between changes in brain activation and task-switching behavioral performance. Cognitively normal older adults were randomly assigned to either the TCC or control (CON) group. Over a 12-week period, the TCC group received three 60-min sessions of Yang-style TCC training weekly, whereas the CON group only received one telephone consultation biweekly and did not alter their life style. All participants underwent assessments of physical functions and neuropsychological functions of task-switching, and fMRI scans, before and after the intervention. Twenty-six (TCC, N = 16; CON, N = 10) participants completed the entire experimental procedure. We found significant group by time interaction effects on behavioral and brain activation measures. Specifically, the TCC group showed improved physical function, decreased errors on task-switching performance, and increased left superior frontal activation for Switch > Non-switch contrast from pre- to post-intervention, that were not seen in the CON group. Intriguingly, TCC participants with greater prefrontal activation increases in the switch condition from pre- to post-intervention presented greater reductions in task-switching errors. These findings suggest that TCC training could potentially provide benefits to some, although not all, older adults to enhance the function of their prefrontal activations during task-switching.

已有研究表明，太极拳（Tai Chi Chuan, TCC）训练对任务切换能力具有积极效益，但TCC训练改善任务切换能力的神经关联机制仍未明确。本研究采用结合数字Stroop范式的任务态功能磁共振成像（functional magnetic resonance imaging, fMRI）技术，探究了TCC训练前后认知正常老年人在任务切换过程中的前额叶脑激活变化与行为表现，并分析了脑激活变化与任务切换行为表现改善之间的关联。研究将认知功能正常的老年人随机分为太极拳训练组（TCC组）与对照组（CON组）。在为期12周的干预周期内，TCC组每周接受3次、每次60分钟的杨氏太极拳训练，而CON组仅每两周接受1次电话咨询，且未改变其日常生活方式。所有受试者在干预前后均接受了躯体功能、任务切换相关神经心理功能评估，以及fMRI扫描。最终共有26名受试者完成全部实验流程，其中TCC组16人，CON组10人。研究发现组别与时间的交互作用对行为指标与脑激活指标均存在显著影响。具体而言，相较于对照组，TCC组在干预后躯体功能显著提升，任务切换行为的错误率显著降低，且在“任务切换>任务不切换”的对比条件下，左侧额上回的脑激活水平显著升高。值得注意的是，在任务切换条件下，前额叶激活水平提升幅度更大的TCC组受试者，其任务切换错误率的降低幅度也更为显著。本研究结果提示，太极拳训练或可使部分而非全部老年人受益，帮助其在任务切换过程中增强前额叶脑激活功能。