فراشناخت و حافظه اپیزودیک در اختلال وسواس

Memory deficits in patients with obsessive-compulsive disorder (OCD) have been frequently reported but are not sufficiently accounted for by cognitive models of OCD. The aim of the study was to identify cognitive mechanisms that might be able to explain memory deficits in OCD. We hypothesized that a self-conscious meta-cognitive style might be responsible for reduced memory performance in OCD. Episodic verbal memory performance was assessed in 23 participants with OCD (DSM-IV criteria) and 22 matched controls. Cognitive self-consciousness was assessed with a self-report measure derived from the Meta-Cognitions Questionnaire (MCQ). Compared to controls, OCD participants showed reduced immediate and delayed recall of complex verbal material and increased self-reported levels of cognitive self-consciousness. Multiple regression analyses indicated that group differences in story recall were significantly mediated by self-reported trait cognitive self-consciousness. Results point to the deteriorating effects of a thought-focused cognitive style on effortful encoding processes in OCD.

Deficits in the area of learning and memory are among the most frequently reported neuropsychological findings in people with obsessive-compulsive disorder (OCD) (see Kuelz, Hohagen, & Voderholzer, 2004; Muller & Roberts, 2005, for review). What remains unclear from previous investigations is how deficits in learning and memory relate to the psychopathological symptoms of OCD. Do memory problems contribute to or even cause obsessive-compulsive psychopathology or are they a consequence of OCD symptoms instead? Neurobiological models of OCD have attributed learning and memory deficits in OCD to deficient organizational strategies thought to arise from dysfunctions in frontostriatal pathways (Deckersbach, Otto, Savage, Baer, & Jenike, 2000; Savage et al., 1999; Savage et al., 2000). Cognitive models of OCD emphasize the negative appraisal of intrusive thoughts, which subsequently leads to neutralizing behavior (Rachman, 1997 and Rachman, 1998; Salkovskis, 1985 and Salkovskis, 1989). These cognitive theories of OCD focus on dysfunctional thought contents. They only rarely attempt to incorporate information processing deficits. An early memory deficit theory of OCD sought to explain pathological doubt and checking rituals by low memory accuracy ( Sher, Frost, Kushner, Crews, & Alexander, 1989; Sher, Frost, & Otto, 1983). This model conceptualized obsessive-compulsive pathology as a consequence of preexisting memory problems but the theory has failed to find consistent empirical support ( Moritz, Jacobsen, Willenborg, Jelinek, & Fricke, 2006; Tallis, Pratt, & Jamani, 1999). During the last decade original appraisal-belief-models have been extended to incorporate abnormal meta-cognitive processing in OCD (Purdon & Clark, 1999; Wells, 2000; Wells & Matthews, 1996). The Obsessive Compulsive Cognition Working Group (OCCWG) has emphasized the overimportance of thoughts and control of thoughts as dimensions of dysfunctional (meta-)cognition in people with OCD (OCCWG, 2001 and OCCWG, 2003). Meta-cognition refers to cognitive processes and structures that monitor and control a person's own cognition. Two specific constructs of meta-cognitive processing have been linked in particular to memory performance in OCD. Both meta-cognitive models conceptualize memory problems as arising from OCD pathology rather than conditioning it: First, people with OCD, especially of the checking subtype, have been repeatedly shown to have low confidence in their own memory performance (Hermans, Martens, De Cort, Pieters, & Eelen, 2003; Macdonald, Antony, Macleod, & Richter, 1997; Rachman, 2002; Tolin et al., 2001) which is further reduced by constant checking (van den Hout and Kindt, 2003 and van den Hout and Kindt, 2004). Second, people with OCD show a heightened tendency to focus attention on their own mental processes regardless of thought contents. This meta-cognitive characteristic, termed cognitive self-consciousness (CSC), has been shown to be especially linked to obsessive-compulsive pathology (Cartwright-Hatton & Wells, 1997; Cohen & Calamari, 2004; Janeck, Calamari, Rieman, & Heffelfinger, 2003). Cognitive self-consciousness might be seen as a predisposition that renders participants more vulnerable to development of obsessions and compulsions because it makes intrusive negative thoughts more salient and increases the probability of dysfunctional thought appraisal, especially of assigning too much importance to passing thoughts. Increased cognitive self-consciousness, as it draws on the limited resources of controlled attention, might also disturb performance on effortful cognitive tasks (e.g. episodic memory or problem-solving). Empirical support for the role of cognitive self-consciousness in deficient memory performance of OCD participants comes from recent research findings: Compared to normal controls (Marker, Calamari, Woodard, & Riemann, 2006) and to subjects with non-OCD anxiety disorders (Goldman et al., 2008) OCD participants were found to show impaired performance on an implicit serial reaction time test, but enhanced recognition of the embedded stimulus pattern. Thus, heightened levels of cognitive self-consciousness might be seen as conscious processing gating problems. This increases likelihood of normally unattended and undetected information (e.g. an embedded structure in the serial reaction time task or negative intrusive thoughts) to enter consciousness and interfere with ongoing cognitive tasks. In an own previous investigation we found Rumination (a subscale of the Padua Inventory) to be the aspect of OC pathology with the strongest association to episodic memory deficits in participants with OCD ( Exner, Martin, & Rief, in press). The psychopathological dimension of Rumination appears to be closely related to the concepts of self-focused attention (situational) and self-consciousness (dispositional self-attention) as it represents a cognitive style that is characterized by an increased attentional focus on internal mental processes and a sense of reduced control over own mental activities. We suggested that increased attention to one's own thoughts and monitoring of own mental processes might distract persons with OCD from memory tasks at hand and thus hamper them in the use of effortful encoding strategies. The aim of the present study was to look beyond group differences on standard memory measures between people with OCD and healthy controls in order to understand the mechanisms associated with reduced memory performance in OCD. Building on our previous observations the purpose of the present investigation was to study the proposed influence of a self-conscious meta-cognitive style on episodic memory processing directly and in a new OCD sample. We specifically hypothesized that increased levels of cognitive self-consciousness would have a mediating effect on episodic memory performance of participants with OCD.