健康与遗传心理学研究室知识库

研究发现认知干预、运动干预、无创伤性脑刺激等非药物干预在提高老年人认知功能、预防老年痴呆发挥着重要作用。探明老年人大脑功能可塑性对于理解老年人大脑可塑性的内在机制以及预防老年痴呆等神经退行性疾病有重要意义。非药物干预就是通过提高老年人大脑可塑性来提高认知功能的，这为研究老年人大脑可塑性提供了机会。

为了描述老年人大脑功能可塑性的清晰图景，本研究分别通过任务态仃叨租和静息态fMRI这两项研究对该问题进行深入探究。

研究一从任务态的角度，采用基于ALE(激活似然性)元分析方法，对现有符合文献纳入标准的16项相关脑成像研究进行定量分析，得到非药物干预引发脑活动的改变主要位于额叶和顶叶，覆盖了默认网络(DMN ) ,额顶网络(FPN ) ,背侧注意网络(VAN)、腹侧注意网络(DAN、突显网络((SN)、感觉运动网络 (SMN，其中DAN, VAN, SMN, FPN-B表现出干预之后脑活动增加，DMN,SN, FPN-C表现出干预之后脑活动减少。以往研究显示，长期训练相较于短期训练可以引发更大区域的脑活动的改变，然而本研究并没有发现这种模式。

研究二从静息态的角度，对课题组己有的4项非药物干预研究(认知干预、经颅磁刺激、经颅电刺激、多模态干预)的干预前后测脑影像数据进行预处理分析(实验组共计84人，控制组共计78人)，经过质量控制和筛选，实验组有62人，控制组有59人纳入最终的分析。根据研究一得到的结果，研究二将发生主要改变的脑网络视为靶网络，探究非药物干预对目标靶网络局部脑特征和全局脑特征的影响。结果显示非药物干预对静息态下局部脑特征的改变作用有限，更多是作用于全局脑特征的改变，特别是FPN, DMN, DAN各个子网络与其他靶网络之间的功能连接。而这些网络间功能连接的改变与行为成绩的改变呈现显著的相关关系。

本研究证实老年人的大脑可塑性是选择性的，FPN, DMN, DAN的可塑性较高，非药物干预一方面可能通过作用于那些受老化进程损伤严重的脑网络，如DMN, DAN，来延缓认知衰退的速度;另一方面可能作用于那些具有一般认知功能(如注意)的大脑区域，如DAN，或是作用于对其他网络具有整体协调功能的FPN，来提高大脑可塑性。研究一与研究二相互补充和验证，揭示了独立于非药物干预类型的大脑功能可塑性结论，这为探明老年人大脑功能可塑性提供了一定的提示性证据。

Non-pharmacological interventions, including cognitive training, aerobics, and non-invasion brain stimulations, have been increasingly demonstrated helpful to improve cognition, prevent dementia in older age. Exploring the neuroplasticity of the old adults plays an essential role in understanding the internal mechanism of the brain plasticity and preventing neurodegenerative diseases (such as Alzheimer's disease). Non- pharmacological interventions can enhance cognitive function by improving the brain plasticity of the elderly, which provides opportunities for studying the brain plasticity of the elderly.

To describe the clear picture of the plasticity of brain function in the elderly, we explored this scientific question through two meta-analyses of task-related fMRI and resting-state fMRI.

From the perspective of the task-related fMRI, study 1 adopted a meta-analysis method based on activation likelihood estimate (ALE) to quantitatively analyze 16 related brain imaging studies that met the criteria for literature inclusion. Results showed brain activity changes caused by non-pharmacological intervention mainly located in the frontal and parietal regions, covering networks such as default mode network (DMN), frontoparietal network (FPN), ventral attention network (VAN),dorsal attention network (DAN), silence network (SN), and sensorimotor network (SMN). Among them, DAN, VAN, SMN, and FPN-B show increased activity after the intervention, while FPN-C showed reduced activity. Previous studies have shown that long-term training can cause brain activity changes in a larger area than short-term training. However, this study did not find this pattern. From the perspective of resting-state fMRI，Study 2 adopted four kinds of nonpharmacological intervention studies (cognitive intervention, transcranial magnetic stimulation, transcranial direct current stimulation, and multidomain intervention) consisting of 83 subjects in the experimental group and 78 subjects in the control group.After the preprocessed procedure, quality control, and screening, 62 people in the experimental group and 58 people in the control group were included in the final analysis. Based on study 1 results, regard those changed brain networks after intervention as target networks, and explore the effect of non-pharmacological interventions on the local and global brain characteristics of those target networks. Results showed that non-pharmacological interventions have limited effects on local brain characteristics, and have significant effects on global brain characteristics, especially the functional connectivity between FPN, DMN, DAN sub-networks, and other target networks. The changes in the functional connectivity between those networks significantly correlated with behavioral achievements.

Our results indicate that non-pharmacological interventions can selectively promote brain activation changes. Some of those changed brain areas such as DAN, DMN, are located in those brain regions that were vulnerable to the aging process; some changed brain areas such as DAN and FPN, are located in those brain region with general cognitive function (like attention) which were usually required to participate in the training process or play a key on coordinating other networks activity. Study 1 and Study 2 complement and verify each other and revealed the functional brain plasticity pattern independent of the type of non-pharmacological intervention. The present metaanalysis may provide the basis for understanding the neuroplasticity of old adults.