Eliane C.P. Dek

Perseverative and compulsive-like staring causes uncertainty about perception

Earlier studies have found that perseverative checking provokes memory distrust for checked stimuli, suggesting that compulsive checking is a counter-productive strategy to increase memory confidence. Obsessive Compulsive (OC) uncertainty also occurs for functions other than memory, like perception. Uncertainty about perception in OC patients gives rise to prolonged attending to the issues that patients feel uncertain about. In an experiment with 40 healthy volunteers, it was tested whether OC-like, perseverative (visual) attending induces OC-like experiences of dissociation and perceptual uncertainty. Participants had to look at an object (a gas stove or a light bulb) during a pre-test and a post-test. In between these tests, participants in the experimental condition were asked to stare at an object that was the same as the to-be-looked-at object during the pre/post-tests. Participants in the control condition stared at an object that was different from the object they looked at during pre/post-test. Both in the experimental and control conditions, dissociation was observed; the effects were equally strong. Critically, with regards to OC-like perceptual uncertainty, the effects were significantly stronger in the experimental condition. The findings indicate that OC-like perseveration induces distrust, not only about memory, but also about perception. To explain the results, we suggest that perseveration interferes with spreading of activation and that cognitive uncertainty (and possibly derealisation) is the experiential end-product of perseveration. It is suggested that all forms of OC perseveration share such interference and that all undermine confidence in cognitive operations.

Uncertainty about perception and dissociation after compulsive-like staring: Time course of effects

Repeated and compulsive-like checking reduces confidence in memory for the last check. Obsessive-compulsive (OC) patients are not only uncertain about memory, but may also be uncertain about perception, while this perceptual uncertainty may be associated with prolonged visual fixation on the object of uncertainty. It was reported earlier that, among healthy participants, prolonged staring at light bulbs or gas rings induces OC-like uncertainty about perception and feelings of dissociation [van den Hout, M. A., Engelhard, I. M., de Boer, C., du Bois, A., & Dek, E. (2008). Perseverative and compulsive-like staring causes uncertainty about perception. Behaviour Research and Therapy, 46, 1300-1304]. In that study, staring continued for 10min. For patients, however, staring intervals seem to be considerably shorter. To test the clinical credibility of the paradigm as a model of the maintenance of OC perceptual uncertainty, we investigated whether the effects of staring materialize long before 10min. Five groups of 16 undergraduates participated: one group did not stare at a gas stove while the others stared for 7.5, 15, 30 or 300s. In the absence of staring, no pre-to-post increase in dissociation/uncertainty was reported, but after staring it was. The larger part of the observed dissociation/uncertainty after 5min had occurred within 30s, and around 50% of this maximal increase was reported between 7.5 and 15s. Thus, even relatively short intervals of staring induce uncertainty about perception and dissociative experiences. Perseverative looking at objects may be a counter-productive OC strategy, which increases uncertainty about perception and may serve to maintain the disorder.

Repeated checking causes distrust in memory but not in attention and perception.

Repeated checking to reduce memory distrust seems to be counterproductive: it increases memory distrust. Obsessive-compulsive (OC) patients tend to be uncertain about other cognitive domains as well, like attention and perception. In an experiment with 70 healthy participants, we tested whether perseverative checking induces distrust not only in memory, but also in attention and perception. Participants were administered a computer task in which they had to activate, deactivate, and check threat-irrelevant stimuli, and rate their confidence in memory, attention, and perception in a pre-test and post-test. In between these tests, the relevant checking group performed 20 checks of the same stimuli used in the pre- and post-test. The irrelevant checking group performed 20 checks of different stimuli. Although memory accuracy improved in both groups, repeated checking reduced confidence in memory, vividness, and detail in the relevant checking group, but not in the irrelevant checking group. A trend was found towards a decline in attentional confidence in the relevant checking group only. Perception was not affected by repetitive checking. A replication study revealed similar results of relevant checking on meta-memory, however, the trend for attentional distrust was not confirmed. The results suggest that perseveration may be domain specific, i.e., only the cognitive processes that are subject to perseveration are affected.

Ironic effects of compulsive perseveration

Individuals with obsessive-compulsive disorder (OCD) exhibit perseverative behaviours, like checking, to reduce uncertainty, but perseveration paradoxically enhances uncertainty. It is unclear what mechanism might be responsible. We hypothesised that perseverative OC-like behaviour produces “semantic satiation” and interferes with the accessibility of meaning. Healthy participants repeated 20 types of OC-like checking behaviour nonperseveratively (2 times) or perseveratively (20 times). Afterwards, they decided as quickly as possible whether a picture was semantically related to the checked object. The nonperseverative condition showed spreading of activation: Judgements were faster for related than for unrelated objects and pictures. The effect was blocked in the perseverative condition, where reaction times for related and unrelated items were similar. The results suggest that the ironic effects of compulsive perseveration are due to interference with spreading of activation.

Automatization and familiarity in repeated checking: A replication:

Repetitive, compulsive-like checking of an object leads to reductions in memory confidence, vividness, and detail. Experimental research suggests that this is caused by increased familiarity with perceptual characteristics of the stimulus and automatization of the checking procedure (Dek, van den Hout, Giele, & Engelhard, 2014). This suggests that defamiliarization by modifying perceptual characteristics of the stimulus will result in de-automatization and attenuation of the meta-memory effects. However, this was not found (Dek et al., 2014), but the manipulation may have been too weak. In two experiments, the present investigation examined whether modification of the defamiliarization procedure (i.e., enlarging the amount of color alterations of the stimuli) would result in de-automatization and attenuation of the metamemory effects. Undergraduates performed a checking task, in which they activated, de-activated, and checked stimuli. Meta-memory was rated after a pre- and post-test checking trial. Simultaneously, automatization of checking was measured with a reaction time task during the pre- and post-test checking trial. In the reaction time task participants responded as quickly as possible to tones. In both experiments, perseverative checking reduced memory confidence, vividness, and detail, and led to automatization of checking behavior. In Experiment I, moderate defamiliarization led to de-automatization, but did not attenuate meta-memory effects of checking. In Experiment II, strong defamiliarization did not lead to de-automatization, but did reduce the detrimental effects of re-checking on memory confidence and vividness. This research suggests that automatization is a potential mechanism underlying the paradoxical phenomenon of perseveration leading to memory uncertainty.

Repeated checking induces uncertainty about future threat

Studies have shown that obsessive-compulsive (OC) -like repeated checking paradoxically increases memory uncertainty. This study tested if checking also induces uncertainty about future threat by impairing the distinction between danger and safety cues. Participants (n = 54) engaged in a simulated checking task, in which they completed two series of 19 checking trials. The experimental group checked burners on a stove and the control group checked light bulbs. Participants completed two pre-tests (before the first series of checks) and two post-tests (one after the first series of checks, the other after the second series). In these tests, they first checked the stove and answered questions about memory confidence and accuracy. Then one of two conditioned stimuli (CS; i.e., a circle) was presented. A CS+ replaced a burner that was on, and a CS- replaced a burner that had been switched off. During each CS presentation, participants rated their shock (UCS) expectancy and confidence about UCS occurrence. Next, the CS+ was followed by the UCS. Analyses showed that the first series of checks did not affect memory accuracy and UCS expectancy, but did reduce confidence about memory and about UCS occurrence in the experimental group, relative to the control group. The second series of checks did not lead to these group differences, compared to the first series. The results demonstrate that repeated checking increases uncertainty not only about memory, but also about future threat.