Differential role of visuospatial working memory in the propensity toward uncertainty in patients with obsessive-compulsive disorder and in healthy subjects

Investigating Retrospective and Prospective Metamemory Judgments During Episodic Memory in Patients With Obsessive-Compulsive Disorders

It is clear evidence that individuals diagnosed with obsessive-compulsive disorder (OCD) lack confidence in their memory and have low metamemory performance (judgment and accuracy). However, it is still unclear whether low metamemory performance is specific to first, domain general or domain specific, and second, to stimulus domain. To address these issues, we compared individuals diagnosed with OCD and healthy controls (HCs) on recognition, retrospective (judgments of learning [JOL]) and prospective (feeling of knowing [FOK]) metamemory judgments and under three different episodic memory tasks, which consisted of symptom-free, familiar and unfamiliar stimuli (word, scene, and face photo). OCD patients showed lower recognition performance, JOL and FOK judgments, and accuracy in all tasks than HCs. Also, OCD patients were slower than HCs during all cognitive performances. In both groups, metamemory performances were lower in familiar items than unfamiliar items. However, recognition performances were not affected by stimulus type. Our results support the idea of general episodic memory and a metamemory deficit in OCD. Moreover, metamemory deficits in OCD are domain general.

A network perspective on cognitive function and obsessive-compulsive related symptoms

BACKGROUND

The relationship between cognitive function and psychopathological symptoms has been an important research field in recent years. Previous studies have typically applied case-control designs to explore differences in certain cognitive variables. Multivariate analyses are needed to deepen our understanding of the intercorrelations among cognitive and symptom phenotypes in OCD.

METHODS

The present study used network analysis to construct networks of cognitive variables and OCD-related symptoms in patients with OCD and healthy controls (N = 226), aiming to explore the relationship among numerous cognitive function variables and OCD-related symptoms in detail and compare the network features between the two groups.

RESULTS

In the network of cognitive function and OCD-related symptoms, nodes representing IQ, letter/number span test, accuracy of task switching test and obsession were much important in the network in terms of their larger strengths and edges. By constructing the networks of these two groups respectively, there was a strong similarity except that the symptom's network in healthy group had a higher degree of overall connectivity.

LIMITATIONS

Due to the small sample size, the stability of the network cannot be guaranteed. Due to the cross-sectional nature of the data, we were unable to determine how the cognitive-symptom network would change with disease deterioration or treatment.

CONCLUSIONS

The present study highlights the important role of variables such as obsession and IQ from a network perspective. These results deepen our understanding of the multivariate relationship between cognitive dysfunction and OCD symptoms, and may promote the prediction and diagnosis of OCD.

Visuospatial working memory capacity moderates the relationship between anxiety and OCD related checking behaviors

BACKGROUND

Compulsive checking behavior is the most prevalent compulsive behavior in patients with obsessive-compulsive disorder (OCD). While some studies have shown that anxiety and executive function influence compulsive checking behavior, the relationship between these constructs is inconclusive. Hence, we sought to explore the interplay between executive function, anxiety and compulsive checking behavior.

MATERIALS AND METHODS

47 healthy participants (HC) and 51 patients with OCD participated in the study. Symptoms and emotional states were assessed using the Yale-Brown Obsessive Compulsive Scale, the Obsessive-Compulsive Inventory-Revised, the Beck Anxiety Inventory, and the Beck Depression Inventory. Participants also completed three tests of neuropsychological functioning: the Stop Signal Task, the Spatial working memory Task, and the Wisconsin card sorting test. We analyzed the relationships between anxiety, executive function, and compulsive checking symptoms.

RESULTS

Patients with OCD showed significantly greater anxiety (p < 0.001) and impairments in visuospatial working memory function (p = 0.030) compared to HC participants, while inhibition and set-shifting were not significantly different between the two groups. Visuospatial working memory was negatively related to compulsive checking behavior (p = 0.016). Visuospatial working memory also played a moderating role in the positive relationship between anxiety and compulsive checking behavior (β = -0.281, p = 0.022).

CONCLUSION

Anxiety symptoms play an important role in explaining compulsive checking behavior in patients with OCD who have relatively weak visuospatial working memory ability. These findings provide a foundation for further research regarding the roles of emotion and cognitive inflexibility in compulsive checking behavior in patients with OCD.

Disrupted pathways from frontal-parietal cortex to basal ganglia and cerebellum in patients with unmedicated obsessive compulsive disorder as observed by whole-brain resting-state effective connectivity analysis - a small sample pilot study

OBJECTIVE

To date, a systematic characterization of abnormalities in resting-state effective connectivity (rsEC) in obsessive-compulsive disorder (OCD) is lacking. The present study aimed to systematically characterize whole-brain rsEC in OCD patients as compared to healthy controls.

METHODS

Using resting-state fMRI data of 50 unmedicated patients with OCD and 50 healthy participants, we constructed whole-brain rsEC networks using Granger causality analysis followed by univariate and multivariate comparisons between patients and controls. Similar analyses were performed for resting-state functional connectivity (rsFC) networks to examine how rsFC and rsEC differentially capture abnormal brain connectivity in OCD.

RESULTS

Univariate comparisons identified 10 rsEC networks that were significantly disrupted in patients, and which were mainly associated with frontal-parietal cortex, basal ganglia, and cerebellum. Conversely, abnormal rsFC networks were widely distributed throughout the whole brain. Multivariate pattern analysis revealed a classification accuracy as high as 80.5% for distinguishing patients from controls using combined whole-brain rsEC and rsFC.

CONCLUSIONS

The results of the present study suggest disrupted communication of information from frontal-parietal cortex to basal ganglia and cerebellum in OCD patients. Using combined whole-brain rsEC and rsFC, multivariate pattern analysis revealed a classification accuracy as high as 80.5% for distinguishing patients from controls. The alterations observed in OCD patients could aid in identifying treatment mechanisms for OCD.

Disrupted pathways from the frontal-parietal cortices to basal nuclei and the cerebellum are a feature of the obsessive-compulsive disorder spectrum and can be used to aid in early differential diagnosis

A marker for distinguishing patients with obsessive-compulsive disorder (OCD) spectrum has not yet been identified. Whole-brain resting-state effective and functional connectivity (rsEC and rsFC, respectively) networks were constructed for 50 unmedicated OCD (U-OCD) patients, 45 OCD patients in clinical remission (COCD), 47 treatment-resistant OCD (T-OCD) patients, 42 chronic schizophrenia patients who exhibit OCD symptoms (SCHOCD), and 50 healthy controls (HCs). Multivariate pattern analysis (MVPA) was performed to investigate the accuracy of using connectivity alterations to distinguished among the aforementioned groups. Compared to HCs, rsEC connections were significantly disrupted in the U-OCD (n = 15), COCD (n = 8), and T-OCD (n = 19) groups. Additionally, 21 rsEC connections were significantly disrupted in the T-OCD group compared to the SCHOCD group. The disrupted rsEC networks were associated mainly with the frontal-parietal cortex, basal ganglia, limbic regions, and the cerebellum. Classification accuracies for distinguishing OCD patients from HCs and SCHOCD patients ranged from 66.6% to 98.0%. In conclusion, disrupted communication from the frontal-parietal cortices to subcortical basal nuclei and the cerebellum may represent a functional pathological feature of the OCD spectrum. MVPA based on both abnormal rsEC and rsFC patterns may aid in early differential diagnosis of OCD.

Free operant observing in humans: a translational approach to compulsive certainty seeking

Excessive checking is reported in non-clinical populations and is a pervasive symptom in obsessive compulsive disorder (OCD). We implemented a free-operant task in humans, previously used in rats, wherein participants can "check" to reduce uncertainty. Participants can press an observing key to ascertain which of two main keys will, if pressed, currently lead to rewards. Over a series of experiments, we found that punishment robustly increased observing in non-clinical participants and that observing persisted long after punishment was removed. Moreover, participants appeared insensitive to the initial costs of checking, and a threefold increase in the effort required to observe served to deter participants only to a limited degree. We also assessed observing in OCD patients with no known comorbidities. The patients observed more than control participants and were abnormally insensitive to the introduction of punishment. These findings support the translational value of the task, with similar behaviours in humans and rodents. This paradigm may serve as a unifying platform, promoting interaction between different approaches to analyse adaptive and maladaptive certainty seeking behaviours. Specifically, we demonstrate how seemingly disparate theoretical and empirical approaches can be reconciled synergistically to promote a combined behavioural and cognitive account of certainty seeking.

Evidence accumulation in obsessive-compulsive disorder: the role of uncertainty and monetary reward on perceptual decision-making thresholds

The compulsive behaviour underlying obsessive-compulsive disorder (OCD) may be related to abnormalities in decision-making. The inability to commit to ultimate decisions, for example, patients unable to decide whether their hands are sufficiently clean, may reflect failures in accumulating sufficient evidence before a decision. Here we investigate the process of evidence accumulation in OCD in perceptual discrimination, hypothesizing enhanced evidence accumulation relative to healthy volunteers. Twenty-eight OCD patients and thirty-five controls were tested with a low-level visual perceptual task (random-dot-motion task, RDMT) and two response conflict control tasks. Regression analysis across different motion coherence levels and Hierarchical Drift Diffusion Modelling (HDDM) were used to characterize response strategies between groups in the RDMT. Patients required more evidence under high uncertainty perceptual contexts, as indexed by longer response time and higher decision boundaries. HDDM, which defines a decision when accumulated noisy evidence reaches a decision boundary, further showed slower drift rate towards the decision boundary reflecting poorer quality of evidence entering the decision process in patients under low uncertainty. With monetary incentives emphasizing speed and penalty for slower responses, patients decreased the decision thresholds relative to controls, accumulating less evidence in low uncertainty. These findings were unrelated to visual perceptual deficits and response conflict. This study provides evidence for impaired decision-formation processes in OCD, with a differential influence of high and low uncertainty contexts on evidence accumulation (decision threshold) and on the quality of evidence gathered (drift rates). It further emphasizes that OCD patients are sensitive to monetary incentives heightening speed in the speed-accuracy tradeoff, improving evidence accumulation.

Excessive checking behavior during an image comparison task in schizophrenia

BACKGROUND

Patients with schizophrenia display significant working memory and executive deficits. In patients with obsessive-compulsive disorder (OCD), several studies suggest that working memory dysfunction may be one of the causes of compulsive checking behaviors. Hence, this study aimed at assessing whether patients with schizophrenia were impaired on an image comparison task used to measure checking behaviors, and whether the origin and profile of impairment on this task was different between schizophrenia and OCD.

METHODS

Eye movement recordings were used to assess the checking behavior of 24 patients with schizophrenia and 24 control participants who had to decide whether two images were different or identical. The verbal and visuo-spatial components of participants' working memory were measured using the reading span and backward location span tests.

RESULTS

Compared to controls, patients with schizophrenia had reduced working memory spans and showed excessive checking behavior when comparing the two images. However, the intensity of their checking behavior was not significantly related to their working memory deficits.

CONCLUSIONS

Several recent studies demonstrated that the excessive checking behaviors displayed by patients with OCD were related to working memory dysfunction. The absence of a relationship between the excessive checking behavior of patients with schizophrenia and their working memory deficits suggests that checking behaviors do not have the same origin in the two disorders.