解離傾向者的注意力與記憶控制

Abstract

解離被定義為整合性功能被打斷的狀態。除了臨床上解離疾患個案所展現的病態性解離症狀外，有些解離經驗在一般族群中是常見的。日常生活中自主性解離的程度被認作是一種人格特質般的傾向，且可能反映一種特定的訊息處理模式。這樣的認知處理模式被認為可能增加壓力事件後的心理疾病發展。過去的研究者嘗試利用不同的認知實驗派點來研究解離特質可能的訊息處理模式。然而，兩個與臨床症狀可能有關的認知功能至今尚未被檢視。本論文有兩個主要目的。第一，我們將發展一個測量解離特質的中文版標準化工具，並了解此工具在本地文化下的心理計量特質與建構效度。第二，我們將研究高解離傾向者的注意力與記憶控制功能。本論文中包含三個獨立的研究。第一個研究焦點放在檢視「解離經驗量表」的因素架構。解離經驗量表的因素架構至今仍是一個爭議，而這個議題的發展也牽涉到不同理論間的整合。我們利用探索性和驗證性因素分析檢視一個大學生樣本中解離經驗的因素結構。在一開始的探索性因素分析得到一個三因子的因素架構，接下來藉由驗證性因素分析所進行的模式比較進一步驗證三因子因素架構的合宜性。因此，三因子的因素架構是解離經驗量表的最合適模式。第二個研究目的在了解非臨床解離傾向者的注意力控制功能，我們採用了一個認知轉移派典來檢驗高解離傾向者在負向情緒下的模組轉移能力。結果顯示高解離傾向者在負向情緒下能較快的將注意力從原本專注的模組移開並將注意力導引到新的模組；而高解離傾向者在注意力集中或無情緒情境中的模組轉移能力則與低解離傾向無顯著差異。第三個研究採用一個提取練習的派典檢視高解離傾向者的選擇性提取功能。過去的研究顯示，當受試者在提取練習階段選擇性提取特定類別中的目標例子時，此類別中其他未獲得提取練習的例子在記憶表現上會顯著的差於基準類別的例子（來自於從未練習過的類別的例子），即提取產生的遺忘。實驗的結果顯示，高解離傾向者並沒有展現出提取產生的遺忘。實驗結果反映兩種可能的解釋。第一個是曾經用來解釋高解離傾向者有較好工作記憶的功能假設：高解離傾向者有著增強的認知功能，在負向情緒中有更好的注意力控制，且在記憶控制中不需要抑制與行為目標無關的訊息。第二個是記憶表徵破碎假設：高解離傾向者的記憶表徵可能破碎，所以在必要情境會經驗到表徵的轉換，且在記憶控制中無須壓抑非競爭性的無關訊息。未來的研究需要著手驗證兩個解釋的正確性，並研究認知控制在不同的情境中如何與記憶表徵交互作用。

Dissociation is defined as disruption in ordinary integrated functions. In addition to the pathological dissociation in patients with dissociative disorders, some dissociative experiences are prevalent in general population. The tendency to dissociate in daily activities has been suggested as a trait-like proneness which is featured by distinctive information processing styles. It has been suggested that these cognitive styles may increase ones’ vulnerabilities to develop certain psychiatric disorders after stressful events. To fully understand how the information processing styles may underlie the cognitive functions of dissociation, researchers have adopted various paradigms in their investigation. However, two functions have not been examined and they may link to the symptoms that characterize clinical patients’ behaviors. The goal of this thesis is twofold. The first objective is to translate a standardized instrument which is designed to measure trait dissociation and examine its construct validity in Chinese culture. The second objective is to investigate the attention and memory control operations of individuals with high dissociation proneness. Three independent studies were conducted. The first study focused on the factor structure of the Dissociative Experiences Scale as this issue is currently under debate and has significant impacts on the integration of theoretical viewpoints on dissociation. Both the exploratory (EFA) and confirmatory factor analyses (CFA) were conducted in a large-scale college sample. A three-factor solution was first derived form the EFA and then verified with the CFA results via model comparison. The three-factor solution is the fittest model for the DES. The second study focused on nonclinical dissociators’ attentional control functions. A set switching paradigm was used to examine dissociators’ switching function under negative emotion. The results showed that high dissociators under negative emotion were faster in disengaging attention from a previous set and diverting their attention to a new set. High dissociators did not differ from low dissociators in their basic function of focused attention or set-switching in the baseline condition where emotion was not aroused. In the third study, a retrieval practice paradigm was adopted to examine dissociators’ selective retrieval function in memory control. Previous studies using this paradigm have shown retrieval-induced-forgetting (RIF) when participants need to selectively retrieve a particular category exemplar in the practice phase. Memory of the distractor exemplar was worse than the memory of unpracticed categorical exemplars. The results showed that the RIF effect was eliminated in high dissociators. The results suggest two possibilities. The first one is the capacity hypothesis that has been proposed to explain better working memory ability of dissociators. With enhanced capacity, dissociators are better in attentional control when in negative emotion and they do not need to inhibit task-irrelevant information in memory control. The second hypothesis is that the mental representations of dissociators may be fragmented so that they are experienced in switching between representations when necessary and do not need to inhibit task-irrelevant information in memory control. Future research should investigate which hypothesis holds true for dissociators and uncover how the control mechanisms interact with mental representations in different task contexts.