思考壓抑與強迫傾向於認知彈性之效果

Abstract

思考壓抑被認為可能是強迫症的致病因素之一。過去思考壓抑研究多聚焦於探討壓抑是否會導致壓抑目標更易於再現，但較少關注若思考壓抑後，在難以成功壓抑時，個體難以自壓抑目標轉移的現象。本研究企圖以作業轉換典範對不同強迫傾向者在思考壓抑後的難以轉移現象進行研究。本研究以不同強迫傾向之大學生為受試者，先請受試者在低認知負荷的狀況下進行不同型式的思考監控(執行思考壓抑與否)，隨後請受試者在較高認知負荷下，即同時進行思考監控與作業轉換，探討此二不同型式的思考監控在認知資源較不足時，是否會在認知彈性上有所差異。研究結果顯示，雙重作業使受試者較難壓抑，且至少對高強迫傾向者而言，思考壓抑對認知彈性有負面影響，亦即高強迫傾向者執行思考壓抑會降低其認知彈性，支持過去認為思考壓抑長期而言為一不佳控制策略之結論。且本研究亦發現，相較於思考壓抑，高強迫傾向者執行表達時，其認知彈性較佳，顯示表達是一較佳的認知策略。本研究亦對此結果於臨床上之應用、限制與未來研究方向加以討論。

Thought suppression is thought to be one of the etiological factors for Obsessive-Compulsive Disorder. Past research on thought suppression primarily focused on the ease of return to suppressed thoughts, namely, rebound effect. However, less research focused on the difficulty of escape from suppressed thoughts. We aimed to study the phenomena of difficulty to escape on obsessive-compulsive tendency participants using task-switching paradigm, which was composed by spatial-cuing task. Firstly, participants with high/low obsessive-compulsive tendency were randomly assigned to one of the two thought monitoring tasks, namely, thought suppression or expression under lower cognitive loading. Then, they conducted the same thought monitoring task under higher cognitive loading situation. That is, they had to conduct the same thought monitoring task and spatial-cuing task simultaneously. The results showed dual task (thought monitoring task with spatial-cuing task) would increase the difficulty to suppress unwanted thoughts. More importantly, for people with high obsessive-compulsive tendency, thought suppression would depress their cognitive flexibility, while expression would lead to better cognitive flexibility and was a better cognitive strategy. Besides, our results supported past research finding that thought suppression was a paradoxical strategy. The implications of the results, limitations, and future research possibilities are discussed.