Practice does not make perfect. The ironic effects of compulsive perseveration

A core feature of obsessive-compulsive disorder (OCD) is a persistent and debilitating doubt. This motivates checking behavior to obtain more certainty. However, after checking repeatedly, patients with OCD are still uncertain. These feelings of uncertainty have a distinct dissociative character. OCD is a debilitating disorder and associated with serious impairments in daily functioning; some patients can barely leave the house because their checking rituals are so time-consuming. Their compulsive behavior is typically ‘perseverative’: it may go on beyond the point where the goal of the action is reasonably reached. Former research has shown that repeated checking itself has paradoxical effects: it increases memory uncertainty. Furthermore, perseverative staring induces uncertainty about perception. These results seem to be special cases of an encompassing phenomenon: ‘perseverationàuncertainty’, and suggest that research should be broadened to confidence in other cognitive processes. The first aim of Karin Giele’s dissertation was to investigate the generality of the ‘perseveration à uncertainty’ phenomenon by testing the effects of perseveration on cognitive distrust in three other domains. The first study showed that sentence repetition induced semantic uncertainty in healthy participants and this effect increased with more sentence repetitions. In the second study was demonstrated that step-by-step OC-like ‘perseverative reasoning’ towards an improbable harmful outcome enhanced the credibility of this catastrophe. Contrary to our expectations, feelings of uncertainty about the outcome increased in all groups; perseverative reasoning did not contribute to this effect. The third study conducted with healthy participants showed that repeated checking not only increased uncertainty about memory but also induced uncertainty about future threat. The second aim was to test a mechanism by which perseveration induces uncertainty. After a stimulus is perceived, semantically related concepts get more accessible. However, if a stimulus is repeatedly processed (e.g., repeating the word ‘fruit’), this spreading of activation may be inhibited; semantically related concepts (e.g., the word ‘apple’) become less accessible. It was tested ifperseveration ofOCD-like behaviour interferes with the spreading of activation of related concepts and thereby affects meaning. The experiential end-point may be the feelings of dissociation and uncertainty that patients with OCD experience. In the fourth study, healthy participants were instructed to decide whether a checked object and picture were related. Results showed that, after 2 checks, participantswere faster in their relatedness decisions for related than for unrelated objects and pictures. This spreading of activation effect was blocked after 20 repetitions; the speed of relatedness decisions for related and unrelated objects and pictures were equal.The last study further examined these satiation effects of perseveration in patients with OCD. Contrary to the findings of chapter 5, no objective effects of a blocked spreading of activation were found after repeating words. However, perseveration induced dissociative uncertainty and this effect was stronger in OCD patients; they reported higher rates of dissociative uncertainty after perseveration compared to controls. In sum, the results showed that perseveration is a counterproductive strategy and further research needs to be conducted to unravel the underlying mechanism behind this perseveration à uncertainty phenomenon.