Attentional biases in body dysmorphic disorder (BDD): Eye-tracking using the emotional Stroop task

A systematic review of visual processing in body dysmorphic disorder (BDD)

To understand the visual preponderance of perceived flaws in appearance in body dysmorphic disorder (BDD), the study of visual processing has been growing. Studies have focused on facial and other basic visual stimuli. The current literature does not provide evidence of consistent behavioural patterns, lacking an overarching body of work describing visual processing in BDD. This systematic review aims to characterise behavioural outcomes of visual processing anomalies and/or deficits in BDD. Articles were collected through online databases MEDLINE and PubMed, and were included if they comprised a clinical BDD group, and were published after 1990. Results indicate that individuals with BDD demonstrate deficits in emotional face processing, a possible overreliance on detail processing, aberrant eye-scanning behaviours, and a tendency to overvalue attractiveness. While findings consistently signal towards visual deficits in BDD, there is lack of clarity as to the type. This inconsistency may be attributed to heterogeneity within BDD samples and differences in experimental design (i.e., stimuli, tasks, conditions). There are difficulties distinguishing between BDD-associated deficits and those associated with OCD or eating disorders. A coherent framework, including sample characterisation and task design will seek to generate clear and consistent behavioural patterns to guide future treatments.

Visual Perceptual Processing Abnormalities in Body Dysmorphic Disorder

Phenomenological observations of individuals with body dysmorphic disorder (BDD), coupled with evidence from neuropsychological, psychophysical, and neuroimaging studies, support a model of aberrant visual perception characterized by deficient global/holistic, enhanced detail/local processing, and selective visual-attentional biases. These features may contribute to the core symptomatology of distorted perception of their appearance, in addition to misinterpretation of others' facial expressions and poor insight regarding their misperceived appearance defects. Insights from visual processing studies can contribute to the development of novel interventions, such as perceptual retraining and non-invasive neuromodulation. However, much remains to be understood about visual perception in BDD. Future research should leverage brain imaging modalities with high temporal resolutions and employ study designs that induce conflicts in multisensory integration, thereby advancing our mechanistic understanding of distorted visual perception observed in BDD.

A conceptual framework on body representations and their relevance for mental disorders

Many mental disorders are accompanied by distortions in the way the own body is perceived and represented (e.g., eating disorders, body dysmorphic disorder including muscle dysmorphia, or body integrity dysphoria). We are interested in the way these distortions develop and aim at better understanding their role in mental health across the lifespan. For this purpose, we first propose a conceptual framework of body representation that defines this construct and integrates different perspectives (e.g., cognitive neuroscience, clinical psychology) on body representations. The framework consists of a structural and a process model of body representation emphasizing different goals: the structural model aims to support researchers from different disciplines to structure results from studies and help collectively accumulate knowledge about body representations and their role in mental disorders. The process model is reflecting the dynamics during the information processing of body-related stimuli. It aims to serve as a motor for (experimental) study development on how distorted body representations emerge and might be changed. Second, we use this framework to review the normative development of body representations as well as the development of mental disorders that relate to body representations with the aim to further clarify the potential transdiagnostic role of body representations.

Unravelling brain connectivity patterns in body dysmorphic disorder during decision-making on visual illusions: A graph theoretical approach

Body dysmorphic disorder (BDD) is characterized by an excessive preoccupation with perceived defects in physical appearance, and is associated with compulsive checking. Visual illusions are illusory or distorted subjective perceptions of visual stimuli, which are induced by specific visual cues or contexts. While previous research has investigated visual processing in BDD, the decision-making processes involved in visual illusion processing remain unknown. The current study addressed this gap by investigating the brain connectivity patterns of BDD patients during decision-making about visual illusions. Thirty-six adults - 18 BDD (9 female) and 18 healthy controls (10 female) - viewed 39 visual illusions while their EEG was recorded. For each image, participants were asked to indicate (1) whether they perceived the illusory features of the images; and (2) their degree of confidence in their response. Our results did not uncover group-level differences in susceptibility to visual illusions, supporting the idea that higher-order differences, as opposed to lower-level visual impairments, can account for the visual processing differences that have previously been reported in BDD. However, the BDD group had lower confidence ratings when they reported illusory percepts, reflecting increased feelings of doubt. At the neural level, individuals with BDD showed greater theta band connectivity while making decisions about the visual illusions, likely reflecting higher intolerance to uncertainty and thus increased performance monitoring. Finally, control participants showed increased left-to-right and front-to-back directed connectivity in the alpha band, which may suggest more efficient top-down modulation of sensory areas in control participants compared to individuals with BDD. Overall, our findings are consistent with the idea that higher-order disruptions in BDD are associated with increased performance monitoring during decision-making, which may be related to constant mental rechecking of responses.

Attention allocation in OCD: A systematic review and meta-analysis of eye-tracking-based research

INTRODUCTION

Cognitive models of obsessive-compulsive disorder (OCD) implicate heightened attention allocation to stimuli related to one's obsessions in the disorder. Recently, to overcome several limitations of reaction time-based measures, eye-tracking methodology has been increasingly used in attentional research.

METHODS

A meta-analysis of studies examining attention allocation towards OCD-related vs. neutral stimuli, using eye-tracking methodology and a group-comparison design, was conducted conforming to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Separate meta-analyses were performed for attentional vigilance (both latency and location of first fixations) and maintenance (total dwell time and total fixation count, conjointly). Each meta-analysis was conducted twice - once including all studies (main analysis) and once only including studies using the free-viewing paradigm (secondary analysis).

RESULTS

The systematic search yielded a total of nine studies. Of those, eight provided the needed data to be included in the meta-analysis. No evidence emerged for vigilance via latency to first fixation. Vigilance reflected via first fixation location emerged in the main analysis, but not in the secondary one. Evidence for attentional maintenance was found only when analyzing free-viewing studies exclusively (the secondary analysis).

LIMITATIONS

To increase the accuracy of the research question, correlational studies were excluded, resulting in a small number of available studies.

CONCLUSIONS

OCD may be characterized by vigilance, but mainly in tasks entailing specific demands and/or goals. Conversely, attentional maintenance may be evident only when using tasks that pose no requirements or demands for participants.

Understanding and treating body dysmorphic disorder

Body dysmorphic disorder (BDD) is a mental disorder that involves a distressing preoccupation with a perceived defect in physical appearance, associated with excessive or repetitive behaviours or mental acts aimed at camouflaging, checking or 'improving' the perceived area of concern. BDD is relatively common, affecting at least 2% of the population world-wide, yet is poorly understood. Professor Susan Rossell has produced a substantial body of influential research, which has improved our understanding of BDD. This includes a more comprehensive understanding of the phenomenology, neurocognition and neurobiology, as well as significant treatment advances. This work will be reviewed in this commentary.

Deciding on Optical Illusions: Reduced Alpha Power in Body Dysmorphic Disorder

BACKGROUND

Body dysmorphic disorder (BDD) is a psychiatric disorder characterized by excessive preoccupation with imagined defects in appearance. Optical illusions induce illusory effects that distort the presented stimulus, thus leading to ambiguous percepts. Using electroencephalography (EEG), we investigated whether BDD is related to differentiated perception during illusory percepts.

METHODS

A total of 18 BDD patients and 18 controls were presented with 39 optical illusions together with a statement testing whether or not they perceived the illusion. After a delay period, they were prompted to answer whether the statement was right/wrong and their degree of confidence in their answer. We investigated differences of BDD patients on task performance and self-reported confidence and analyzed the brain oscillations during decision-making using nonparametric cluster statistics.

RESULTS

Behaviorally, the BDD group exhibited reduced confidence when responding incorrectly, potentially attributed to higher levels of doubt. Electrophysiologically, the BDD group showed significantly reduced alpha power at the fronto-central and parietal scalp areas, suggesting impaired allocation of attention. Interestingly, the lower the alpha power of the identified cluster, the higher the BDD severity, as assessed by BDD psychometrics.

CONCLUSIONS

Results evidenced that alpha power during illusory processing might serve as a quantitative EEG biomarker of BDD, potentially associated with reduced inhibition of task-irrelevant areas.

Instantaneous radiated power of brain activity: application to prepulse inhibition and facilitation for body dysmorphic disorder

Background

Global measures of neuronal activity embrace the advantage of a univariate, holistic and unique description of brain activity, reducing the spatial dimensions of electroencephalography (EEG) analysis at the cost of lower precision in localizing effects. In this work, the instantaneous radiated power (IRP) is proposed as a new whole-brain descriptor, reflecting the cortical activity from an exclusively electromagnetic perspective. Considering that the brain consists of multiple elementary dipoles, the whole-brain IRP takes into account the radiational contribution of all cortical sources. Unlike conventional EEG analyses that evaluate a large number of scalp or source locations, IRP reflects a whole-brain, event-related measure and forces the analysis to focus on a single time-series, thus efficiently reducing the EEG spatial dimensions and multiple comparisons.

Results

To apply the developed methodology in real EEG data, two groups (25 controls vs 30 body dysmorphic disorder, BDD, patients) were matched for age and sex and tested in a prepulse inhibition (PPI) and facilitation (PPF) paradigm. Two global brain descriptors were extracted for between-groups and between-conditions comparison purposes, namely the global field power (GFP) and the whole-brain IRP. Results showed that IRP can replicate the expected condition differences (with PPF being greater than PPI responses), exhibiting also reduced levels in BDD compared to control group overall. There were also similar outcomes using GFP and IRP, suggesting consistency between the two measures. Finally, regression analysis showed that the PPI-related IRP (during N100 time-window) is negatively correlated with BDD psychometric scores.

Conclusions

Investigating the brain activity with IRP significantly reduces the data dimensionality, giving insights about global brain synchronization and strength. We conclude that IRP can replicate the existing evidence regarding sensorimotor gating effects, revealing also group electrophysiological alterations. Finally, electrophysiological IRP responses exhibited correlations with BDD psychometrics, potentially useful as supplementary tool in BDD symptomatology.

Early auditory-evoked potentials in body dysmorphic disorder: An ERP/sLORETA study

Body dysmorphic disorder (BDD) is characterized by excessive preoccupation with imagined or slight physical defects in appearance. BDD is associated with cognitive impairments (attention, visual processing). Our study aims to evaluate the early neural responses (N100, P200) to prepulse inhibition (PPI) and prepulse facilitation (PPF), to investigate attentional processing of BDD in the auditory domain. Fifty-five adults took part: 30 BDD patients and 25 healthy controls. We compared their brain responses to PPI and PPF by analyzing global field power (GFP), event-related potentials (ERPs) and their respective sources. BDD exhibited reduced N100 amplitudes compared to healthy controls in response to the startle tone elicited by both PPI and PPF, potentially suggesting impaired allocation of attention. Interestingly, the lower the GFP at the N100, the higher the BDD severity. Source reconstruction analysis showed reduced activation for BDD during the N100 time window in PPI. Scalp responses and source activations in PPI were decreased overall compared to PPF, confirming the gating effect of PPI. We provided evidence that the N100 may serve as an electrophysiological marker of BDD, predicting its severity. Our study demonstrated the potential of using ERPs combined with behavioural PPI and PPF protocols to advance our understanding of BDD pathophysiology.

Internet-delivered cognitive behavioural therapy for perfectionism: Targeting dysmorphic concern

Perfectionism is an important transdiagnostic risk factor for several psychopathologies. As such, treatments targeting perfectionism have gained increased attention over recent years. While perfectionism is postulated to be an important underlying mechanism for dysmorphic concern, no research has explored the benefits of targeting perfectionism to reduce dysmorphic concern. The current study evaluated the use of Internet-delivered cognitive behavioural therapy for perfectionism (ICBT-P) with 31 participants (28 women) with high levels of dysmorphic concern to examine the impact on perfectionism, dysmorphic concern, body image disturbance, negative affect, and selective attention towards appearance-based stimuli. Using a case series design, observations were collected at baseline, at the end of a 4-week pre-treatment phase, after the 8-week ICBT-P, and 1-month post-treatment. Intent-to-treat analyses showed significant improvement from baseline to end-of-treatment and follow-up on most of the variables, with a large effect size decrease in dysmorphic concern, and decreased selective attention to BDD-body, BDD-positive, and BDD-negative words. The results of this study support the use of ICBT-P as an efficacious treatment worthy of further examination in populations who experience high levels of dysmorphic concern.

The relationship between body dysmorphic disorder and obsessive-compulsive disorder: A systematic review of direct comparative studies

OBJECTIVE

Current nosology conceptualises body dysmorphic disorder as being related to obsessive-compulsive disorder, but the direct evidence to support this conceptualisation is mixed. In this systematic review, we aimed to provide an integrated overview of research that has directly compared body dysmorphic disorder and obsessive-compulsive disorder.

METHOD

The PubMed database was searched for empirical studies which had directly compared body dysmorphic disorder and obsessive-compulsive disorder groups across any subject matter. Of 379 records, 31 met inclusion criteria and were reviewed.

RESULTS

Evidence of similarities between body dysmorphic disorder and obsessive-compulsive disorder was identified for broad illness features, including age of onset, illness course, symptom severity and level of functional impairment, as well as high perfectionism and high fear of negative evaluation. However, insight was clearly worse in body dysmorphic disorder than obsessive-compulsive disorder, and preliminary data also suggested unique visual processing features, impaired facial affect recognition, increased social anxiety severity and overall greater social-affective dysregulation in body dysmorphic disorder relative to obsessive-compulsive disorder.

CONCLUSION

Limitations included a restricted number of studies overall, an absence of studies comparing biological parameters (e.g. neuroimaging), and the frequent inclusion of participants with comorbid body dysmorphic disorder and obsessive-compulsive disorder. Risks of interpreting common features as indications of shared underlying mechanisms are explored, and evidence of differences between the disorders are placed in the context of broader research findings. Overall, this review suggests that the current nosological status of body dysmorphic disorder is somewhat tenuous and requires further investigation, with particular focus on dimensional, biological and aetiological elements.

A systematic review and meta-analysis of cognitive processing deficits associated with body dysmorphic disorder

This systematic review and meta-analysis examined the evidence supporting the association between body dysmorphic disorder (BDD) symptomology and four types of cognitive processing abnormalities: local processing, selective attention, interpretive biases, and memory deficits. Twenty-three studies met inclusion requirements that examined differences in performance on cognitive tasks between BDD and control groups across the four categories. Multilevel modelling was used to calculate an overall effect size for each cognitive category. BDD and control groups differed significantly on measures of selective attention (g = 0.60, 95% CI = 0.26: 0.93), interpretive biases (g = 0.30, 95% CI = . 07: 0.54), and memory deficits (g=.56, 95% CI = 0.26: 0.87). Differences between the BDD and control groups on measures of local processing did not reach significance. These findings support the hypothesis that people with BDD may selectively attend to perceived threats or to disorder-related stimuli, misinterpret ambiguous stimuli as threatening, overvalue the importance of attractiveness, and have inaccurate coding and recall for facial or bodily stimuli. Recommendations for future research of these specific cognitive deficits in BDD include introducing the use of Modified Dot Probe Paradigms and new treatment targets that can be used as adjuncts to current treatment modalities.

Neurocognitive Functioning in Young Adults with Subclinical Body Dysmorphic Disorder

Despite reasonable knowledge of body dysmorphic disorder (BDD), little is known of its cognitive antecedents. In this study, we evaluated executive functioning and decision-making in people at risk of developing BDD using neuropsychological tests. Participants were non-treatment seeking volunteers (18-29 years) recruited from the general community, and split into two groups: those "at risk" of developing BDD (N = 5) and controls (N = 82). Participants undertook the One-Touch Stockings of Cambridge, Cambridge Gamble and Spatial Working Memory tasks and were assessed with the Body Dysmorphic Disorder Questionnaire. Results showed that the at-risk subjects performed significantly worse on a measure of executive function, whereas measures of risk-seeking behavior, quality of decision-making, and spatial working memory were largely intact. The findings suggest that selective cognitive dysfunction may already be present in terms of executive functioning in those at risk of developing BDD, even before psychopathology arises.

Using the research domain criteria (RDoC) to conceptualize impulsivity and compulsivity in relation to addiction

Nomenclature for mental disorder was updated in 2013 with the publication of the fifth edition of the Diagnostic and Statistical Manual (DSM-5). In DSM-5, substance use disorders are framed as more dimensional. First, the distinction between abuse and dependence is replaced by substance use. Second, the addictions section now covers both substances and behavioral addictions. This contemporary move toward dimensionality and transdiagnosis in the addictions and other disorders embrace accumulating cognitive-affective neurobiological evidence that is reflected in the United States' National Institutes of Health Research Domain Criteria (NIH RDoC). The RDoC calls for the further development of transdiagnostic approaches to psychopathy and includes five domains to improve research. Additionally, the RDoC suggests that these domains can be measured in terms of specific units of analysis. In line with these suggestions, recent publications have stimulated updated neurobiological conceptualizations of two transdiagnostic concepts, namely impulsivity and compulsivity and their interactions that are applicable to addictive disorders. However, there has not yet been a review to examine the constructs of impulsivity and compulsivity in relation to addiction in light of the research-oriented RDoC. By doing so it may become clearer as to whether impulsivity and compulsivity function antagonistically, complementarily or in some other way at the behavioral, cognitive, and neural level and how this relationship underpins addiction. Thus, here we consider research into impulsivity and compulsivity in light of the transdiagnostic RDoC to help better understand these concepts and their application to evidence-based clinical intervention for addiction.

Treatment Modifications and Suggestions to Address Visual Abnormalities in Body Dysmorphic Disorder

Recent psychophysical and neurocognitive findings implicate abnormal visual processing for a range of stimuli in body dysmorphic disorder (BDD); such abnormalities differentiate BDD from other mental health disorders. Current treatments most commonly involve cognitive behavior therapy with or without accompanying antidepressant medications. These are moderately successful yet appear to overlook the core phenomenological aspect of abnormal perception in BDD. The following text summarizes the current literature of perceptual abnormalities within BDD and how these findings may be applied and incorporated into treatment options. Possible modifications of cognitive behavioral therapy (CBT) based on the widespread visual abnormalities within BDD include making perceptual mirror retraining a compulsory component of therapy and implementing self-exposure tasks within exposure and response prevention. Alternative options such as a visual training program to remediate visual abnormalities across a range of visual stimuli are also explored, which may be included as an adjunctive treatment alongside CBT.