Disgust and fear responding in contamination-based obsessive-compulsive disorder during pictorial exposure

Identifying emotional components of event-related potentials in the brain functioning of individuals with contamination obsessions and comparison with healthy control group

The present study aimed to examine the emotional components of event-related potentials (ERPs) in individuals with contamination OCD and compare them with a healthy control group. A convenience sample of 45 participants was included, consisting of 30 individuals diagnosed with contamination-type OCD and 15 individuals in a healthy control group. Both groups participated in an ERP study where they encountered a computer-based task presenting both contamination and neutral pictures, while their brain activity was recorded. The data were analyzed using repeated measures analysis of variance (RANOVA) with SPSS-24 and Matlab software. Findings suggest that in P3 amplitude, only individuals with OCD exhibited a larger positive amplitude (p < 0.05) in response to contaminated pictures compared to neutral pictures and in N2 amplitude, only individuals with OCD exhibited a larger negative amplitude (p < 0.05) in response to contaminated pictures compared to neutral pictures in the central vertex (Fz). These findings hold promising implications for the development of more targeted and effective treatments for contamination OCD, emphasizing the importance of emotion-oriented approaches to address the unique neural patterns observed in the frontal vertex.

Disgust sensitivity mediates the link between homophobia and sexual orientation obsessive-compulsive symptoms

Previous research has shown that intrusive thoughts in obsessive-compulsive disorder (OCD) often focus on emotionally significant aspects of individuals' lives (e.g., values and beliefs). The current study sought to expand our understanding of OC symptoms related to sexual orientation (SO-OC symptoms) by investigating the roles of homophobia (i.e., negative attitudes, affect, and behaviors toward individuals with a same-gender orientation) and disgust propensity and sensitivity. A total of 592 self-identified heterosexual college students were recruited to complete measures of homophobia, disgust propensity and sensitivity, and SO-OC symptoms. Results of separate parallel mediation analyses indicated that the relationships between homophobic affect/attitudes and avoidance/aggression on one hand, and SO-OC symptoms on the other, were partially mediated specifically by disgust sensitivity, after controlling for gender. Theoretical and clinical implications are discussed, including how homophobia can be conceptualized as a disgust response in the treatment of SO-OC symptoms, as well as how other constructs of potential interest (sexual and moral disgust, religiosity, conservative sexual ideology) can be examined in future research.

Attentional Processing of Disgust and Fear and Its Relationship With Contamination-Based Obsessive-Compulsive Symptoms: Stronger Response Urgency to Disgusting Stimuli in Disgust-Prone Individuals

Disgust has recently been characterized as a low-urgency emotion, particularly compared to fear. The aim of the present study is to clarify whether behavioral inhibition during disgust engagement is characteristic of a low-urgency emotion and thus indicates self-imposed attentional avoidance in comparison to fear. Therefore, 54 healthy participants performed an emotional go/no-go task with disgust- and fear-relevant as well as neutral pictures. Furthermore, heart rate activity and facial muscle activity on the fear-specific m. corrugator supercilli and the disgust-specific m. levator labii were assessed. The results partially support the temporal urgency hypothesis of disgust. The emotion conditions significantly differed in emotional engagement and in the facial muscle activity of the m. levator labii as expected. However, contrary to our expectations, no differences between the emotion conditions regarding behavioral inhibition as well as heart rate change could be found. Furthermore, individuals with a higher-trait disgust proneness showed faster reactions and higher activity of the m. levator labii in response to disgust stimuli. The results show that different trait levels influence attentional engagement and physiological parameters but have only a small effect on behavioral inhibition.

Long-term modulation of cardiac activity induced by inhibitory control over emotional memories

Efforts to exclude past experiences from conscious awareness can lead to forgetting. Memory suppression is central to affective disorders, but we still do not really know whether emotions, including their physiological causes, are also impacted by this process in normal functioning individuals. In two studies, we measured the after-effects of suppressing negative memories on cardiac response in healthy participants. Results of Study 1 revealed that efficient control of memories was associated with long-term inhibition of the cardiac deceleration that is normally induced by disgusting stimuli. Attempts to suppress sad memories, by contrast, aggravated the cardiac response, an effect that was closely related to the inability to forget this specific material. In Study 2, electroencephalography revealed a reduction in power in the theta (3-8 Hz), alpha (8-12 Hz) and low-beta (13-20 Hz) bands during the suppression of unwanted memories, compared with their voluntary recall. Interestingly, however, the reduction of power in the theta frequency band during memory control was related to a subsequent inhibition of the cardiac response. These results provide a neurophysiological basis for the influence of memory control mechanisms on the cardiac system, opening up new avenues and questions for treating intrusive memories using motivated forgetting.

The Role of Perceived Control in the Psychophysiological Responses to Disgust of Subclinical OCD Women

Obsessive‒compulsive disorder (OCD), and especially contamination obsessions and washing compulsions, has been related to disgust. However, when its cardiovascular correlates have been studied, contradictory results have been found, including heart rate accelerations and decelerations. The aim of this study is to analyze emotional, cognitive, and cardiovascular responses in nonclinical (control) and subclinical participants with obsessive‒compulsive contamination/washing symptoms when confronted with a disgusting stimulus. Twenty-seven participants (14 subclinical OCD) completed a behavioral avoidance task with a contamination-based stimulus while their heart rate and subjective variables were measured. Results showed heart rate reductions in both samples, whereas subjective measures reflected higher disgust, anxiety, dirtiness, and emotional valence in the subclinical sample. However, at the same time, the sense of dominance was lower in the control group. In conclusion, our results support a heart rate deceleration during exposure to a disgusting stimulus dissociated from the subjective experience.

Responsibility/Threat Overestimation Moderates the Relationship Between Contamination-Based Disgust and Obsessive-Compulsive Concerns About Sexual Orientation

Disgust has been shown to perform a "disease-avoidance" function in contamination fears. However, no studies have examined the relevance of disgust to obsessive-compulsive (OC) concerns about sexual orientation (e.g., fear of one's sexual orientation transforming against one's will, and compulsive avoidance of same-sex and/or gay or lesbian individuals to prevent that from happening). Therefore, we investigated whether the specific domain of contamination-based disgust (i.e., evoked by the perceived threat of transmission of essences between individuals) predicted OC concerns about sexual orientation, and whether this effect was moderated/amplified by obsessive beliefs, in evaluation of a "sexual orientation transformation-avoidance" function. We recruited 283 self-identified heterosexual college students (152 females, 131 males; mean age = 20.88 years, SD = 3.19) who completed three measures assessing disgust, obsessive beliefs, and OC concerns about sexual orientation. Results showed that contamination-based disgust (β = .17), responsibility/threat overestimation beliefs (β = .15), and their interaction (β = .17) each uniquely predicted OC concerns about sexual orientation, ts = 2.22, 2.50, and 2.90, ps < .05. Post hoc probing indicated that high contamination-based disgust accompanied by strong responsibility/threat overestimation beliefs predicted more severe OC concerns about sexual orientation, β = .48, t = 3.24, p < .001. The present study, therefore, provided preliminary evidence for a "sexual orientation transformation-avoidance" process underlying OC concerns about sexual orientation in heterosexual college students, which is facilitated by contamination-based disgust, and exacerbated by responsibility/threat overestimation beliefs. Treatment for OC concerns about sexual orientation should target such beliefs.

Meta-analytic review of the effects of a single dose of intranasal oxytocin on threat processing in humans

BACKGROUND

Heightened threat sensitivity is a transdiagnostic feature in several psychiatric disorders. The neuropeptide oxytocin has been shown to reduce fear related behaviours and facilitated fear extinction in animals. These findings have led to increasing interest to explore the effects of intranasal oxytocin on threat processing in humans.

METHODS

The review included 26 studies (N = 1173), nine of which included clinical populations (N = 234). The clinical groups included were people with borderline personality disorder (BPD), anorexia nervosa, bulimia nervosa, depression, anxiety, and alcohol dependence disorder. We examined the effects of a single dose of intranasal oxytocin on startle response, attentional responses, and behavioural responses to threat.

RESULTS

A single dose of intranasal oxytocin significantly increased the physiological startle response to threat in healthy people with a small effect size. However, oxytocin did not have significant effects on attentional bias towards social or disorder-specific threat, fixation towards threatening stimuli among healthy or clinical populations, or on threat related behavioural approach or avoidance responses.

LIMITATIONS

No studies investigated the effects of oxytocin on the startle response to threat among clinical populations. Additionally, only one of the reviewed studies had sufficient power to detect at least a moderate effect of oxytocin according to our criterion.

DISCUSSION

The synthesis of literature suggest that oxytocin may influence the salience of threatening stimuli among healthy individuals, increasing the startle response to threat. It would be of interest to investigate the effects of oxytocin on the startle response to threat among clinical populations.

Neuropsychological Functioning in Obsessive-Compulsive Washers: Drug-Naive Without Depressive Symptoms

INTRODUCTION

Obsessive-Compulsive Disorder (OCD) is a complex and heterogeneous neuropsychiatric syndrome. Contamination obsessions and washing/cleaning compulsions are the most frequent clinical OCD subtypes. The current study aimed at examining the neuropsychological impairments in drug-naive obsessive-compulsive (OC) washers without depressive symptoms and their association with the severity of symptoms.

METHODS

In the current causal-comparative study, 35 patients with diagnostic and statistical mental disorders class (DSM)-IV diagnosed with washing-subtype OCD and 35 healthy subjects were selected by the convenience sampling method and evaluated by computerized neuropsychology battery and clinical tests as Stroop Color-Word Test (SCWT), Wisconsin Card Sorting Test (WCST), Go/No-Go Test, Digits Forward (DF), Digits Backward (DB), Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), and General Health Questionnaire (GHQ)-28. The patients were matched to the comparison group with regard to age, gender, intelligence quotient (IQ), education, and handedness. All the tests were standardized in Iran. SPSS version 20.00 was used for descriptive and analytical data analysis.

RESULTS

There was no statistically significant different between the OCD washing and the control groups regarding socio-demographic variables or IQ. There were significant differences between the OC washer and the healthy control groups on the neuropsychological functioning. The obtained results suggested that OC washers performed significantly worse on neuropsychological measures than the controls. There was no significant association between the severity of OC symptoms and the neuropsychological functions in the OCD washing group.

CONCLUSION

It was concluded that executive function impairment, which is a core feature in OC washers was trait-like in nature.

Disgust stimuli reduce heart rate but do not contribute to vasovagal symptoms

BACKGROUND AND OBJECTIVES

The vasovagal response demonstrates a unique form of stress response, common in medical settings yet provoked by a variety of blood-injury-injection stimuli. This study aimed to better understand the psychophysiological mechanisms of the vasovagal response..

METHODS

16 undergraduates with and 42 without a self-reported history of fainting watched five 3-5 min videos with different emotional content. One documentary clip (Neutral condition) described a campus environmental project while another (Blood/Injury) depicted portions of an open heart surgery. Three additional clips were also used, including Medical, Threat, and Contamination stimuli. Vasovagal symptoms and physiological variables were assessed during each video.

RESULTS

As predicted, while the disgust-related stimuli (Blood/Injury, Medical, Contamination) were associated with generally lower heart rate, the Blood/Injury video produced the highest symptoms and the only significant difference between previous fainters and non-fainters. The physiological measures also revealed that participants with a fainting history experienced higher stroke volume and lower systolic blood pressure throughout, as well as several main effects of video.

LIMITATIONS

An additional decrease in systolic blood pressure and respiration produced by watching the Blood/Injury video may have been sufficient to trigger symptoms in some, though results also suggest that systemic variables do not entirely explain susceptibility to symptoms. More careful evaluation of regional blood flow may be required.

CONCLUSIONS

Participants who had previously experienced strong vasovagal responses displayed what appeared to be an anticipatory response to the Blood/Injury video. Finally, disgust stimuli may reduce heart rate but do not appear to contribute to vasovagal symptoms.

Self-Regulation of Anterior Insula with Real-Time fMRI and Its Behavioral Effects in Obsessive-Compulsive Disorder: A Feasibility Study

Introduction

Obsessive-compulsive disorder (OCD) is a common and chronic condition that can have disabling effects throughout the patient's lifespan. Frequent symptoms among OCD patients include fear of contamination and washing compulsions. Several studies have shown a link between contamination fears, disgust over-reactivity, and insula activation in OCD. In concordance with the role of insula in disgust processing, new neural models based on neuroimaging studies suggest that abnormally high activations of insula could be implicated in OCD psychopathology, at least in the subgroup of patients with contamination fears and washing compulsions.

Methods

In the current study, we used a Brain Computer Interface (BCI) based on real-time functional magnetic resonance imaging (rtfMRI) to aid OCD patients to achieve down-regulation of the Blood Oxygenation Level Dependent (BOLD) signal in anterior insula. Our first aim was to investigate whether patients with contamination obsessions and washing compulsions can learn to volitionally decrease (down-regulate) activity in the insula in the presence of disgust/anxiety provoking stimuli. Our second aim was to evaluate the effect of down-regulation on clinical, behavioural and physiological changes pertaining to OCD symptoms. Hence, several pre- and post-training measures were performed, i.e., confronting the patient with a disgust/anxiety inducing real-world object (Ecological Disgust Test), and subjective rating and physiological responses (heart rate, skin conductance level) of disgust towards provoking pictures.

Results

Results of this pilot study, performed in 3 patients (2 females), show that OCD patients can gain self-control of the BOLD activity of insula, albeit to different degrees. In two patients positive changes in behaviour in the EDT were observed following the rtfMRI trainings. Behavioural changes were also confirmed by reductions in the negative valence and in the subjective perception of disgust towards symptom provoking images.

Conclusion

Although preliminary, results of this study confirmed that insula down-regulation is possible in patients suffering from OCD, and that volitional decreases of insula activation could be used for symptom alleviation in this disorder.

Effective behavioural strategies for reducing disgust in contamination-related OCD: A review

Disgust is an understudied but important emotion in various psychological disorders. Over the last decade, increasing evidence suggests that disgust is also present in various subtypes of obsessive-compulsive disorder (OCD), especially in contamination-related OCD (C-OCD). The treatment of choice for C-OCD is exposure with response prevention, originally designed to reduce fear-associated emotions thought to be acquired through Pavlovian conditioning (PC). However, disgust has been proposed to be acquired through evaluative conditioning (EC) and according to the referential model of this form of learning, there are functional differences between PC and EC that need to be considered in the treatment of disgust-related responses. Alternative strategies suggested by EC-based models include counterconditioning (contingent presentation of the CS with a US of opposite valence) and US revaluation (contingent presentation of the US with US of opposite valence). Drawing on the referential model, this paper reviews evidence for the effectiveness of each strategy to identify the most theoretically sound and empirically valid intervention to reduce disgust in C-OCD.

Is the desire for amputation related to disturbed emotion processing? A multiple case study analysis in BIID

Body integrity identity disorder (BIID) is characterized by the overwhelming desire to amputate one or more healthy limbs or to be paraplegic. Recently, a neurological explanation of this condition has been proposed, in part on the basis of findings that the insular cortex might present structural anomalies in these individuals. While these studies focused on body representation, much less is known about emotional processing. Importantly, emotional impairments have been found in psychiatric disorders, and a psychiatric etiology is still a valid alternative to purely neurological accounts of BIID. In this study, we explored, by means of a computerized experiment, facial emotion recognition and emotional responses to disgusting images in seven individuals with BIID, taking into account their clinical features and investigating in detail disgust processing, strongly linked to insular functioning. We demonstrate that BIID is not characterized by a general emotional impairment; rather, there is a selectively reduced disgust response to violations of the body envelope. Taken together, our results support the need to explore this condition under an interdisciplinary perspective, taking into account also emotional connotations and the social modulation of body representation.