高活動量女性長者之視覺空間工作記憶：行為與事件相關電位之研究

Visuospatial Working Memory In Highly Physically Active Female Elders: A Behavioral and ERP Study

研究目的：比較不同身體活動量的女性老年人在執行視覺空間工作記憶情境下，其行為與認知電生理的表現差異。研究方法：以簡式智力測驗量表及七日身體活動回憶問卷篩選出12位心智正常且為高活動量的女性桌球運動老年人當作運動組，以及12位年齡相仿低身體活動量之女性控制組，施測延遲與不延遲視覺空間工作記憶作業情境並同步收錄腦波。研究結果：運動組在執行視覺空間工作記憶情境時，有較快反應時間以及較高正確率的行為表現；從事件相關電位來看，在編碼階段，運動組有較短的頂葉P3潛時及較大的P3振幅，在需要執行動作反應的階段，運動組有較小的N2振幅與較大的P3振幅，不過，在延遲階段則兩組間的CNV面積無顯著差異。研究結論：女性運動組老年人有較佳的視覺空間工作記憶的表現，其隱含的內在神經機轉可能是運動組能有較快且投入較多的注意力資源做空間刺激的編碼，並且在反應階段時，能減少作業相關的反應衝突或監控過程的努力程度，以投入較多的注意力資源做執行反應。因此，從事桌球運動似乎可以達到促進女性老年人的中樞神經功能，以提高視覺空間工作記憶的表現。

Purpose: The behavioral and electrop hysiological performance of highly physically active female elderly adults who regularly engage in table tennis was compared with their low physically active counterparts on a delayed and non-delayed visuospatial working memory task. Methods: We recruited 24 elderly female adults with normal cognitive function and a high/low physically active state based on a screening using the Mini-Mental State Examination and a 7-day physical activity recall questionnaire. Both groups participated in a delayed and non-delayed visuospatial working memory task while their behavior and event- related potentials (ERPs) indices were simultaneously recorded. Results: Faster response time and better response accuracy were evident for the high physically active group than the control one. In terms of ERPs data, the physically active group exhibited larger P3 amplitude and faster P3 latency at Pz in the encoding stage. In addition, in the response stage, smaller N2 and larger P3 amplitude were observed for the high physically active group, but no significant difference was found on the P3 latency and CNV amplitude. Conclusions: Better visuospatial working memory performance was observed for the high physically active group. The neural mechanisms might be that the high physically active group could encode more quickly and allocate more attention resources when encoding. In addition, the high physically active group could reduce the effort in task-related response conflict or monitoring, and increase efficiency when they executed a response. Our findings suggest that bett er performance on visuospatial working memory tasks can be observed in female elderly adults regularly engaging in table tennis via enhanced central nervous system function.