Affordances, response conflict, and enhanced-action tendencies in obsessive-compulsive disorder: an ERP study.

BACKGROUND: Obsessive-compulsive disorder (OCD) is characterized by recurrent, intrusive thoughts and/or behaviors. OCD symptoms are often triggered by external stimuli. Therefore, it has been suggested that difficulty inhibiting responses to stimuli associated with strong action tendencies may underlie symptoms. The present electrophysiological study examined whether stimuli evoking a strong automatic response are associated with enhanced action tendencies in OCD participants relative to healthy controls. METHODS: The lateralized readiness potential (LRP) and the N2 event-related potential (ERP) components were used as measures of action tendencies and inhibition, respectively. ERPs were recorded while 38 participants diagnosed with OCD and 38 healthy controls performed a variation of the Stroop task using colored arrows. RESULTS: The OCD group presented with larger LRP amplitudes than the control group. This effect was found specifically in the incongruent condition. Furthermore, an interaction effect was found between group and congruency such that the OCD group showed a reduced N2 in the incongruent condition compared to the congruent condition, whereas the control group demonstrated the opposite effect. Results support the hypothesis that OCD is characterized by stronger readiness-for-action and impaired inhibitory mechanisms, particularly when the suppression of a dominant response tendency is required. Our results were supported by source localization analyses for the LRP and N2 components. These findings were specific to OCD and not associated with anxiety and depression symptoms. CONCLUSIONS: The present results support the notion of stronger habitual behavior and embodiment tendencies in OCD and impaired inhibitory control under conditions of conflict.

Why check? A meta-analysis of checking in obsessive-compulsive disorder: Threat vs. distrust of senses.

Compulsive checking is the most common ritual among individuals with obsessive-compulsive disorder (OCD). Yet, other than uncertainty, the variables prompting checking are not fully understood. Laboratory studies suggest that task conditions - whether threatening (anxiety-relevant) or neutral, and task type - whether requiring perceptual or reasoning decision-making - may be influential. The purpose of our meta-analysis was to compare OCD participants and healthy controls on experimental tasks involving uncertainty in which a behavioral measure of checking was obtained. Four databases were searched. Twenty-two studies met the inclusion criteria, including 43 conditions comparing 663 OCD participants to 614 healthy controls. Due to the dependent structure of the data a robust variance estimation analysis approach was used. Overall effects were similar for neutral and threatening conditions. However, OCD participants responded with greater checking compared to controls on perceptual tasks, but not on reasoning tasks. Results support previous reports suggesting that OCD checking can be observed in neutral conditions, possibly posing as a risk factor for a checking vicious cycle. In addition, our results support OCD models which focus on checking as stemming from interference with automatic processes and distrust of sensory modalities.

Early cognitive processes in OCD: An ERP study.

BACKGROUND: Obsessive-compulsive disorder (OCD) is characterized by persistent, intrusive, and distressing obsessions and/or compulsions and is associated with marked impairments in quality of life. The goal of the present study was to examine initial stages of information processing, specifically, perceptual and attention orientation phases that precede response preparation in OCD. METHODS: The P3 event-related potential (ERP) component was used as a measure of early cognitive processes of visual stimulus perception. ERPs were recorded while 38 participants diagnosed with OCD and 38 healthy controls performed a passive visual oddball task with neutral and angry schematic faces. RESULTS: OCD participants demonstrated significantly enhanced P3 amplitude over bilateral parietal areas in response to neutral stimuli that activate basic primary perceptual processes. Emotional valence reduced this effect such that OCD patients did not differ from healthy controls in P3 amplitude under the angry stimuli condition. LIMITATIONS: Patients in this study were noncomorbid and unmedicated partially limiting the generalizability of the results. CONCLUSIONS: Our hypothesis of altered early perceptual processes in OCD was supported. These alterations, specific to OCD and not anxiety and depression symptoms, may represent distracted primary cognitive processes in OCD, possibly serving as a basic source for compulsion initiation.

Enhanced action tendencies in obsessive-compulsive disorder: An ERP study.

Obsessive-compulsive disorder (OCD) is characterized by repeated thoughts and behaviors. This study explored the stages of motor response preparation that precede action performance or inhibition: We investigated whether OCD is related to enhanced action tendencies in response to external stimuli. Response preparation processes were assessed using the event-related potential (ERP) component of the readiness potential (RP). ERPs were recorded while 15 participants with OCD and 16 healthy controls performed a variation of the go/no-go task and the stop-signal task using schematic faces (angry and neutral). The OCD group presented with a greater RP slope gradient and amplitude over bilateral frontoparietal areas corresponding to the motor cortex. The amplitude effect was further enhanced under negative valence, compared to the neutral condition. Results support the hypothesis that stronger readiness for action might characterize OCD, especially in the presence of threatening stimuli. These findings - specifically correlated with OCD and not with anxiety and depression symptoms - may underlie habitual behavior and embodiment tendencies in OCD. This study suggests that early stages of motor preparation might be important to the etiology and maintenance of OCD.

Stop checking: Repeated checking and its effects on response inhibition and doubt.

BACKGROUND: Repeated checking is a common ritual in obsessive-compulsive disorder (OCD). van den Hout and Kindt (2003b) devised a task demonstrating paradoxical reductions in memory confidence following repeated checking. This effect was later found to be contingent upon response inhibition. The current study aims to (1) test an alternative interpretation, whereby repeated-checking effects are caused by viewing multiple exemplars, and (2) test whether repeated checking affects response inhibition. METHOD: 132 students participated in two experiments (66 in Experiment 1 and 66 in Experiment 2). Participants were randomly allocated to a repeated-checking task or a simple-action task that featured similar multiple exemplars without the need for checking. Both tasks were followed by a stop-signal task, measuring response inhibition. Experiment 1 featured a stop-signal task with neutral go-signals while Experiment 2 incorporated familiar and unfamiliar stimuli from the previous task as go-signals. RESULTS: In both experiments, the repeated-checking group exhibited reduced memory confidence compared to the simple-action group. Groups did not differ in their response inhibition for neutral stimuli (Experiment 1), while familiar go-signals had a detrimental effect on response inhibition (Experiment 2). LIMITATIONS: Our results examine the association between checking and response inhibition in healthy participants without attention deficit hyperactivity disorder and dyslexia. Replication with clinical samples awaits future studies. CONCLUSIONS: Repeated checking impairs memory confidence. Increased familiarity of stimuli shortens the time it takes to respond to them while it impairs inhibition response to them. These effects possibly provide initial evidence for the hypothesized role of response inhibition in the maintenance of OCD.

Enhanced action tendencies in high versus low obsessive-compulsive symptoms: an event-related potential study.

Obsessive-compulsive disorder (OCD) is an anxiety disorder characterized by repeated thoughts and behaviors. Inhibitory deficits are presumably related to the onset and maintenance of this disorder. The present study investigated whether obsessive-compulsive (OC) symptoms are related to enhanced response tendencies in reaction to external stimuli. Our goal was to search for direct evidence of an early response preparation process by examining the event-related potential (ERP) component of the readiness potential (RP). An enhanced response tendency might underlie inhibitory deficits in OCD. Response to novel stimuli was studied using a dishabituation paradigm in which a small number of schematic faces (angry or neutral) were presented. An analog sample of healthy subjects was divided into groups of high and low OC levels and high and low trait anxiety levels. The high OC group presented with a greater RP slope gradient that was enhanced under negative valence, compared to the low OC group. No such effect was found in the high versus low trait anxiety groups or in behavioral reaction times (ms). Results support the hypothesis that a stronger readiness for action might characterize subjects with OC symptoms, especially in the presence of threatening stimuli. This finding, specific to OC symptoms and not to anxiety symptoms, may underlie habitual and embodiment tendencies in OCD. This study suggests that early stages of motor preparation might be important to the etiology and maintenance of OC symptoms.