| 摘要: | 近年來有許多實徵研究証實運動有助於人類認知能力的改善，然而什麼是確切有效的運動訓練方式並不清楚，也缺乏足夠的功能性與結構性神經造影資料來解釋運動所導致的大腦可塑性機制。本研究計畫目的在於探索能有效改善中年和老年人的「抑制」、「更新」以及「切換」等中央執行功能的運動訓練程序，並利用功能性與擴散張量磁振造影來探討對應之腦部功能與結構變化。實驗一將藉由操弄受試者接受的運動訓練強度(實驗1A)、時間長度(1B)與種類(1C)，找出造成中年人與老年人中央執行功能在前後測中有最大進步的訓練參數。實驗二將採取實驗一中建立的最佳參數對中年人實施訓練，在訓練初始、三個月及六個月時進行功能性與擴散張量磁振造影，探討中年人之「抑制」(實驗2A)、「更新」(2B)、以及「切換」(2C)等中央執行功能，因運動訓練而進步之腦部功能與結構變化。實驗三將在老年受試者身上重覆上述程序(實驗3A、 3B 與3C)，以了解高齡族群對運動訓練所產生的中央執行功能改善情況與相應之腦部機制，並與中年人的資料互相比對以了解運動所致之腦部可塑性的本質。藉由本計畫三個系列的實驗，相信將能為現存關於運動改善認知能力之最佳方式與腦部機制的疑點，提供進一步的答案。 Physical exercise (PE) has been demonstrated to improve various cognitive abilities, particularly central executive functions (CEF), in human beings. However, the optimal protocol inducing such improvement and the underlying functional and structural brain mechanisms remain inconclusive. The current project sets out to seek the optimal training protocols of PE that can lead to significant improvement of CEF in the middle-aged (45-55 year-old) and old (65-75 year-old) adults. Furthermore, the functional and anatomical neural mechanisms underlying the improvement will be assessed with functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI), respectively. Specifically, we will measure and assess the changes of three well documented central executive functions (CEF): inhibition, updating, and shifting both before and after PE that varies in intensity, duration, or types. The pre- and post-exercise difference in the CEF performance would be compared with appropriate control groups in each training protocol to assess the behavioral effect and associated changes in the neural system. Experiment 1 in the first year establish optimal parameters of PE to induce improvement in inhibition, updating, and shifting in the middle-aged and old groups. Experiment 1A will randomly assign participants into different intensities of PE (as defined by percentage of the estimated maximal heart rate reached, 40%, 60%, and 80%), Experiment 1B will randomly assign participants into different durations of PE (15, 30, and 45 minutes), and finally Experiment 1C will randomly assign participants into different types of PE (walking, cycling, and Aerobic exercise). After establishing the optimal intensity, duration, and types of exercise that induces CEF improvement in the targeted population, Experiment 2 in the second year will adopt the most effective training protocol train the middle-aged adults, and these participants will be sent in the MRI scanner both before and after the physical exercise to assess the short-term (within hours) and mid-term (3 and 6 months) changes in the brain. Experiment 2A, 2B, and 2C will examine the functional and anatomical plasticity corresponds to central executive processes (inhibition, updating, shifting), respectively. Finally, Experiment 3A, 3B, and 3C will examine the same CEF-related functional and anatomical changes in the brain of the old adults following the experimental paradigm of Experiment 2. The differences between the old and the middle-aged group in functional activation and structural connectivity will also be compared to examine the nature of neural plasticity associated with PE and improve in CEF. To conclude, the current project will extend existing behavioral literature with more systematical manipulations of PE parameters. It will also complement the EEG literature with neuroimaging data which will provide fine localization of neural networks that are prone to PE-training and are associated with improvement in central executive functions. 研究期間：9908 ~ 10007 |
