急性健身運動對執行功能之影響：事件相關電位與大腦神經滋養因子之研究

Effect of Acute Exercise on Executive Function: An Event-Related Potential and Brain-Derived Neurotropic Factor Study

緒論：多數研究發現急性健身運動對認知功能的正面影響，而此效果可能受認知功能的種類所調節。叫色測驗為被廣泛使用的神經心理測驗之一，其可同時檢測不同類別之認知功能。事件關聯電位可檢測大腦神經電位之變化，瞭解在認知過程中內隱的大腦歷程。大腦衍生神經滋養因子 (Brain-derived Neurotrophic Factor, BDNF) 為神經滋養因子之一，其對大腦神經功能的維持扮演著重要的角色。動物研究發現可透過健身運動提升BDNF的濃度；然而，目前仍缺乏人體研究探討BDNF是否為健身運動增進認知功能的潛在機制。為此，本研究目的在探討急性健身運動對叫色測驗之影響，並以神經電位與生化取向瞭解急性健身運動誘發認知功能改變的潛在機制。方法：本研究招募19名大學生實驗參與者分別參與以平衡次序法實施的健身運動與閱讀控制兩種實驗情境。健身運動情境包含5分鐘暖身、20分鐘中等強度腳踏車運動（約65%儲備心跳率），以及5分鐘的緩和。而閱讀情境則為閱讀體育相關書籍，其介入時間與健身運動情境相同。此外，於二種實驗情境後採集血液樣本，然後進行叫色測驗的施測。結果：急性健身運動後，叫色測驗一致與不一致情境的反應時間皆顯著縮短，而且叫色測驗不一致情境獲得來自急性健身運動的效益大於一致情境。此外，急性健身運動後，有較大P3振幅。然而，P3潛伏時間與BDNF濃度在急性健身運動後未發現明顯變化。結論：中等強度急性健身運動可以增進認知功能，其中，執行功能獲得來自健身運動的效果大於一般認知功能。該效益可能與急性健身運動增進注意力資源分配的提升有關。然而，BDNF的濃度在急性健身運動與認知功能間之角色仍須後續的探究。

Introduction: Majority of studies have supported the positive effects of acute exercise on cognitive function; however, the relationship between acute exercise and cognition may be modulated by type of cognitive function. Stoop test is a widely used neuropsychological test to assess different types of cognition. ERP, a neuroelectric index, provide covert brain processes during cognitive test administration. Brain-derived neurotropic factor (BDNF) is a neurotrophic factor which plays an important role for maintenance of neuron function. Animal studies have shown that exercise increase BDNF concentration; however, mechanisms underlying cognitive improvement in response to acute exercise remind unknown. Therefore, the purpose of the present study was to examine the effects of acute exercise on Stoop test performance and to explore the potential mechanisms underlying exercise-induced cognitive change using neuroelectric and biochemical approaches. Methods: Nineteen collegiate students participated in the study. Participants came to laboratory at the same time in two separate days for exercise and reading control conditions. The two experimental conditions were counterbalanced. Exercise condition consisted of 5-minute warm-up, 20-minute moderate intensity cycling (around 65 % HRR), and 5-minute cool-down. In reading control condition, participants read an exercise-related book for the same duration as exercise condition. Blood samples were obtained immediately following each experimental condition. Results: Shorter response time was found following acute exercise for both Stroop congruent and incongruent conditions compared to reading control condition. Additionally, greater beneficial effects of acute exercise were observed in incongruent condition compared to congruent condition. As for electrophysiological measures, greater P3 amplitude was found after acute exercise compared to reading control condition while changes in P3 latency and concentration of BDNF did not reach significance. Conclusion: acute moderate intensity exercise resulted in improvement in cognitive function. Importantly, more gained has been observed for executive function relative to information processing. Increased allocation of attentional resource may explain why acute exercise benefits cognitive performance. However, BDNF may not be the underlying mechanism for exercise-induced cognitive function improvement, at least for the current exercise protocol. Therefore, future research on exploring the role of other neurotrophic factors in acute exercise-cognition relationship is warranted.