Reality monitoring and motor memory in checking-prone individuals

EEG microstate co-specificity in schizophrenia and obsessive-compulsive disorder

The past 20 years of research on EEG microstates has yielded the hypothesis that the imbalance pattern in the temporal dynamics of microstates C (increased) and D (decreased) is specific to schizophrenia. A similar microstate imbalance has been recently found in obsessive-compulsive disorder (OCD). The aim of the present high-density EEG study was to examine whether this pathological microstate pattern is co-specific to schizophrenia and OCD. We compared microstate temporal dynamics using Bayesian analyses, transition probabilities analyses and the Topographic Electrophysiological State Source-Imaging method for source reconstruction in 24 OCD patients and 28 schizophrenia patients, respectively, free of comorbid psychotic and OCD symptoms, and 27 healthy controls. OCD and schizophrenia patients exhibited the same increased contribution of microstate C, decreased duration and contribution of microstate D and greater D → C transition probabilities, compared with controls. A Bayes factor of 4.424 for the contribution of microstate C, 4.600 and 3.824, respectively, for the duration and contribution of microstate D demonstrated that there was no difference in microstate patterns between the two disorders. Source reconstruction further showed undistinguishable dysregulations between the Salience Network (SN), associated with microstate C, and the Executive Control Network (ECN), associated with microstate D, and between the ECN and cognitive cortico-striato-thalamo-cortical (CSTC) loop in the two disorders. The ECN/CSTC loop dysconnectivity was slightly worsened in schizophrenia. Our findings provide substantial evidence for a common aetiological pathway in schizophrenia and OCD, i.e. microstate co-specificity, and same anomalies in salience and external attention processing, leading to co-expression of symptoms.

Obsessive-compulsive symptoms and dissociative experiences: Suggested underlying mechanisms and implications for science and practice

A strong and specific link between obsessive-compulsive disorder or symptoms (OCD/S) and a tendency for dissociative experiences (e.g., depersonalization-derealization, absorption and imaginative involvement) cannot be explained by trauma and is poorly understood. The present theoretical formulation proposes five different models conceptualizing the relationship. According to Model 1, dissociative experiences result from OCD/S through inward-focused attention and repetition. According to Model 2, dissociative absorption causally brings about both OCD/S and associated cognitive risk factors, such as thought-action fusion, partly through impoverished sense of agency. The remaining models highlight common underlying causal mechanisms: temporo-parietal abnormalities impairing embodiment and sensory integration (Model 3); sleep alterations causing sleepiness and dreamlike thought or mixed sleep-wake states (Model 4); and a hyperactive, intrusive imagery system with a tendency for pictorial thinking (Model 5). The latter model relates to Maladaptive Daydreaming, a suggested dissociative syndrome with strong ties to the obsessive-compulsive spectrum. These five models point to potential directions for future research, as these theoretical accounts may aid the two fields in interacting with each other, to the benefit of both. Finally, several dissociation-informed paths for further developing clinical intervention in OCD are identified.

If you don’t let it in, you don’t have to get it out: Thought preemption as a method to control unwanted thoughts

To attain goals, people must proactively prevent interferences and react to interferences once they occur. Whereas most research focuses on how people deal with external interferences, here we investigate the use of proactive and reactive control in dealing with unwanted thoughts. To examine this question, we asked people to generate an association to each of several repeating cue words, while forbidding the repetition of associations. Reactively rejecting and replacing unwanted repeated associations after they occur entails slower response times. Conversely, proactive control entails constricting the search space and thus faster response times. To gain further insight into different potential proactive thought control mechanisms, we augmented the analysis of raw response times with a novel, hypothesis-based, tractable computational model describing how people serially sample associations. Our results indicate that people primarily react to unwanted thoughts after they occur. Yet, we found evidence for two latent proactive control mechanisms: one that allows people to mitigate the episodic strengthening of repeated thoughts, and another that helps avoid looping in a repetitive thought. Exploratory analysis showed a relationship between model parameters and self-reported individual differences in the control over unwanted thoughts in daily life. The findings indicate the novel task and model can advance our understanding of how people can and cannot control their thoughts and memories, and benefit future research on the mechanisms responsible for unwanted thought in different psychiatric conditions. Finally, we discuss implications concerning the involvement of associative thinking and various control processes in semantic fluency, decision-making and creativity.

The memory deficit hypothesis of compulsive checking in OCD: what are we really talking about? A narrative review

We reviewed studies that have specifically explored the memory deficit hypothesis of Obsessive Compulsive Disorder (OCD) checking, highlighting the methodological differences between these studies that may explain inconsistencies regarding memory deficits in OCD checkers. Based on Conway's proposition that one function of episodic memories is to keep an adaptive record of recent goal processing in order to check that actions have actually been accomplished, we suggest that impaired autonoetic consciousness -one of the main features of episodic memory- may be at the heart of the issue of checking compulsion. Autonoetic consciousness, that can be experimentally assessed by the Remember/Know/Guess paradigm,could be impaired in OCD checkers leading them to be unable to mentally relive their actions in order to be assured that they have been accomplished (e.g., having locked the door). We make methodological suggestions to improve the assessment of autonoetic consciousness deficit in OCD checkers and understand its role in the etiology and maintenance of compulsive checking.

Dissociable source-monitoring impairments in obsessive-compulsive disorder and schizophrenia

BACKGROUND

Based on the observed clinical overlap between obsessive-compulsive disorder (OCD) and schizophrenia (SCZ), both conditions may share, at least in part, common cognitive underpinnings. Among the cognitive deficits that could be involved, it has been hypothesized that patients share a failure in their abilities to monitor their own thoughts (source monitoring), leading to confusion between what they actually did or perceived and what they imagined. Although little is known regarding source-monitoring performances in patients with OCD, numerous studies in patients with SCZ have observed a relationship between delusions and/or hallucinations and deficits in both internal source- and reality-monitoring abilities.

METHODS

The present work compared source-monitoring performances (internal source and reality monitoring) between patients with OCD (n = 32), patients with SCZ (n = 38), and healthy controls (HC; n = 29).

RESULTS

We observed that patients with OCD and patients with SCZ displayed abnormal internal source-monitoring abilities compared to HC. Only patients with SCZ displayed abnormalities in reality monitoring compared to both patients with OCD and HC.

CONCLUSIONS

Internal source-monitoring deficits are shared by patients with OCD and SCZ and may contribute to the shared cognitive deficits that lead to obsessions and delusions. In contrast, reality-monitoring performance seems to differentiate patients with OCD from patients with SCZ.

Review of source-monitoring processes in obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) is a severe mental illness characterized by persistent, intrusive and distressing obsessions and/or compulsions. Such symptoms have been conceptualized as resulting from a failure in source-monitoring processes, suggesting that patients with OCD fail to distinguish actions they perform from those they just imagine doing. In this study, we aimed to provide an updated and exhaustive review of the literature examining the relationship between source-monitoring and OCD. A systematic search in the literature through January 2019 allowed us to identify 13 relevant publications investigating source-monitoring abilities in patients with OCD or participants with subclinical compulsive symptoms. Most of the retrieved studies did not report any source-monitoring deficits in clinical and subclinical subjects compared with healthy volunteers. However, most of the studies reported that patients with OCD and subclinical subjects displayed reduced confidence in source-monitoring judgments or global cognitive confidence compared to controls. The present review highlighted some methodological and statistical limitations. Consequently, further studies are needed to explore source monitoring with regard to the subcategories of OCD symptoms (i.e., symmetry-ordering, contamination-washing, hoarding, aggressive obsession-checking, sexual-religious thoughts) and to clarify the relationship between source-monitoring subtypes (i.e., reality or internal source-monitoring) and confidence in these populations.

Mindfulness-based Cognitive Therapy for Obsessive-Compulsive Disorder: A Pilot Study

BACKGROUND

Cognitive-behavioral therapy (CBT) is the first-choice intervention for obsessive-compulsive disorder (OCD); however, a notable proportion of patients either do not respond to treatment or relapse after CBT. Mindfulness-based treatment has been suggested as an alternative or complementary therapeutic strategy for OCD. However, only a few studies have focused on its application in clinical samples.

OBJECTIVE

To evaluate the impact of a new treatment, called "Mindfulness-based Cognitive Therapy for OCD." It is an 11-session manualized group intervention that integrates elements of CBT, mindfulness, compassion-focused therapy, and acceptance and commitment therapy.

METHODS

The program was delivered to 35 patients with a primary diagnosis of OCD.

RESULTS

Participants demonstrated good adherence to the intervention. There was a significant reduction in mean total score on the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS-TS) (P<0.001; Cohen d=-0.72). One third of the participants (n=13) showed at least a 25% reduction on the Y-BOCS-TS, and 40% of the sample (n=14) were assigned to a lower Y-BOCS severity category after treatment. Significant changes were also found in depression (P<0.001; d=-0.80), worry (P<0.001; d=-0.79), alexithymia (P<0.01; d=-0.41), dissociation (P<0.05; d=-0.46), and general psychopathology (P<0.001; d=-0.58). Repeated measures linear mixed models showed that OCD symptom reduction was associated with an increase in mindfulness skills, in particular on the acting with awareness (P=0.006), nonjudging (P=0.001), and nonreactivity (P=0.001) facets.

CONCLUSIONS

Overall, these findings are promising and they suggest that randomized controlled studies be conducted to test the effectiveness of this new treatment program for this challenging and disabling mental disorder.

Decreased memory confidence in obsessive-compulsive disorder for scenarios high and low on responsibility: is low still too high?

Previous research suggests that patients with obsessive-compulsive disorder (OCD), particularly checkers, display an inflated sense of responsibility. For the present study, we tested whether memory confidence in OCD is reduced under conditions of heightened responsibility and/or reflects poor memory vividness. A computerized task designed to modulate perceived responsibility was administered to 26 OCD patients (12 checkers) and 21 healthy controls. In the experimental condition (high responsibility), participants had to allocate daily medications to ten fictive patients in a hospital emergency ward, whereas in the control condition (low responsibility) participants had to allocate bath essences for ten hotel guests. Participants' response time and accuracy were recorded as well as their memory confidence, memory vividness, and subjective success. Irrespective of the condition, OCD patients performed as accurately as healthy controls, but appraised their performance as worse than that of controls. Memory confidence was decreased in patients, particularly checkers. No group differences emerged on vividness, and none of the effects were moderated by the condition (high versus low responsibility). The relationship between responsibility and OCD behavior is complex. Results suggest metamemory problems in OCD checkers, even when induced responsibility is low. The findings speak against "cold" memory deficits in OCD, as patients did not differ from controls on accuracy, reaction time, or vividness. Future research should focus on idiosyncratic beliefs and scenarios that inflate responsibility and elicit cognitive biases.

Relationship between symptom dimensions and white matter alterations in obsessive-compulsive disorder

OBJECTIVE

To investigate the relationship between the severities of symptom dimensions in obsessive-compulsive disorder (OCD) and white matter alterations.

METHODS

We applied tract-based spatial statistics for diffusion tensor imaging (DTI) acquired by 3T magnetic resonance imaging. First, we compared fractional anisotropy (FA) between 20 OCD patients and 30 healthy controls (HC). Then, applying whole brain analysis, we searched the brain regions showing correlations between the severities of symptom dimensions assessed by Obsessive-Compulsive Inventory-Revised and FA in all participants. Finally, we calculated the correlations between the six symptom dimensions and multiple DTI measures [FA, axial diffusivity (AD), radial diffusivity (RD), mean diffusivity (MD)] in a region-of-interest (ROI) analysis and explored the differences between OCD patients and HC.

RESULTS

There were no between-group differences in FA or brain region correlations between the severities of symptom dimensions and FA in any of the participants. ROI analysis revealed negative correlations between checking severity and left inferior frontal gyrus white matter and left middle temporal gyrus white matter and a positive correlation between ordering severity and right precuneus in FA in OCD compared with HC. We also found negative correlations between ordering severity and right precuneus in RD, between obsessing severities and right supramarginal gyrus in AD and MD, and between hoarding severity and right insular gyrus in AD.

CONCLUSION

Our study supported the hypothesis that the severities of respective symptom dimensions are associated with different patterns of white matter alterations.

The Cognitive Heterogeneity of Obsessive-Compulsive Checking

The present article reviews the phenomenology of obsessive-compulsive checking, examining how action processing can be differentially affected across distinct checking subtypes. Checking is a normal phenomenon which ensures that an intended goal has been actually completed. Checking symptoms have consistently been connected to impairments in processing information related to self-performances. Theoretical and empirical work has explained compulsive checking as a result of various cognitive deficits related to action processing (e.g., low confidence in cognitive abilities, impaired memory for actions, abnormal reality monitoring, overactive action monitoring, defective goal processing). Such apparent inconsistencies are, however, in agreement with clinical and empirical observations highlighting substantial variability in the subjective experience preceding/accompanying checking. Many factors can in fact prevent the cognitive system from determining whether or not an intended goal has actually been achieved. We argue that several action processing mechanisms are likely affected in checking; the related subjective experience may vary accordingly.

Impaired body but not face perception in patients with obsessive-compulsive disorder

BACKGROUND

Empirical evidence involving the processing of social information by patients with obsessive-compulsive disorder (OCD) has been relatively scarce. Our study investigated the perceptual abilities of patients with OCD to recognize human faces and bodies.

METHOD

Fifty-four drug-free or drug-naïve patients with OCD and 42 healthy controls performed discrimination tasks consisting of four types of stimuli: two sets of faces that were manipulated with regard to configuration and features, human bodies, and chairs. The stimuli were presented in upright and upside-down orientations.

RESULTS

Patients with OCD were significantly less accurate in discriminating pairs of bodily postures implying actions. However, we found no significant differences between patient and control groups in the ability to recognize faces and chairs. The inversion effects for bodies and faces were also comparable between the two groups.

CONCLUSIONS

The current findings suggest that patients with OCD experience difficulty in perceiving static forms of bodily postures, but are able to adequately recognize human faces. Our data indicate a selective deficit in the perception of bodily postures in those with OCD and suggest that this deficit is probably not related to the abnormal configurational processing of social objects.

No deficits in nonverbal memory, metamemory and internal as well as external source memory in obsessive-compulsive disorder (OCD)

A large body of literature suggests that some symptoms of obsessive-compulsive disorder (OCD) result from mnemonic dysfunctions. The present study tested various formulations of the memory deficit hypothesis considering important moderators, such as depression and response slowing. Thirty-two OCD patients and 32 healthy controls were presented verbal or nonverbal instructions for actions (e.g. simple gestures). These actions should either be performed or imagined. For recognition, previously presented as well as novel actions were displayed. Decisions had to be made whether an action was previously displayed (verbally vs. nonverbally) or not and whether an action was performed or imagined (internal source memory). Moreover, both judgments required confidence ratings. Groups did not differ in memory accuracy and metamemory for verbally presented material. Patients displayed some impairment for nonverbally presented material and imagined instructions, which, however, could be fully accounted for by response slowing and depressive symptoms. The study challenges the view that primary memory deficits underlie OCD or any of its subtypes. We claim that research should move forward from the mere study of objective impairment to the assessment of cognitive performance in conjunction with personality traits such as inflated responsibility.