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Background: Difficulties with the regulation of negative affect have been extensively studied in neuroimaging research. However, dysregulation of a specific emotion, disgust, has hardly been investigated. In the present study, we used voxel-based morphometry to identify whether gray matter volume (GMV) of frontal regions is correlated with personal...
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Emotion regulation mediates socio‐cognitive functions and is essential for interactions with others. The capacity to automatically inhibit responses to emotional stimuli is an important aspect of emotion regulation; the underlying neural mechanisms of this ability have been rarely investigated. Forty adults completed a Go/No‐go task during magnetoe...
Citations
... The insula sends some projections to the OFC [33,34], the area engaged in coding the aversive value of the stimuli [35], and its enhanced activity, among the insula and other areas, is associated with avoidance behavior in a disgust-relevant situation [36]. The OFC also showed increased gray matter volume in people with higher disgust sensitivity (how much they are distressed when experiencing disgust) [37]. Neuroimaging studies reported the overactivation of OFC in OCD patients [38]. ...
Background
The negative emotional valence of a stimulus can be altered if paired with a pleasant stimulus, a phenomenon referred to as evaluative conditioning. Disgust, as a central emotion in obsessive-compulsive disorder (OCD), particularly in the contamination subtype, may be an appropriate target for such a method. We know that disgust processing and OCD pathophysiology share in some brain areas, including the orbitofrontal cortex, as the neuromodulation techniques targeted in this area have been able to decrease OCD symptoms. We aim to conduct a randomized clinical trial to investigate the evaluative conditioning effect on disgust reduction in patients with contamination-based OCD when administered with or without neuromodulation targeted orbitofrontal cortex.
Method
In a single-blind randomized control trial (RCT), 55 patients with contamination-based OCD will be randomly assigned to four arms. In a factorial design, they will receive 10 sessions of evaluative conditioning training (either sham or real) plus cathodal transcranial direct current stimulation (tDCS) over the orbitofrontal cortex (either sham or real). The intensity of disgust experience and clinical symptoms will be investigated as primary outcomes and quantitative electroencephalogram and cognitive functions as secondary outcomes. The data will be collected at three assessment levels: baseline, after completing intervention sessions, and 2-month follow-up.
Discussion
The present RCT is the first study that applies evaluative conditioning training in the OCD clinical sample. It will clarify the effect of the evaluative conditioning method alone and with tDCS on disgust reduction in patients with contamination-based OCD. It will provide initial evidence for such an emotion modulation method in the OCD population. The effect of this emotion-focused protocol on cognitive functions and electroencephalogram components is also of interest.
Trial registration
ClinicalTrials.gov, NCT05907369. Registered on 16 June 2023. Retrospectively registered.
... First, some researchers used voxel-based morphometry (VBM) to explore the brain structural basis associated with disgust sensitivity. The studies found that the left orbitofrontal cortex was positively correlated with the disgust sensitivity score, and the disgust sensitivity score showed a negative correlation with the gray matter volume of the left medial frontal cortex [23]. Furthermore, the gray matter volume of the insula was positively correlated with food-related disgust sensitivity, the gray matter volumes of the dorsal medial and the dorsolateral prefrontal cortex were negatively correlated with the decay disgust domains, and the gray matter volumes of the orbitofrontal cortex and the dorsolateral prefrontal cortex were negatively correlated with the disgust domains of death [24]. ...
In recent years, more and more studies on disgust have shown the association between disgust and various psychopathologies. Revealing the spontaneous brain activity patterns associated with disgust sensitivity from the perspective of individual differences will give us an insight into the neurologic nature of disgust and its psychopathological vulnerability. Here, we used two modal brain imaging techniques (resting fMRI and resting EEG) to reveal spontaneous brain activity patterns closely related to disgust sensitivity. The amplitude of low-frequency fluctuation results showed that disgust sensitivity is negatively correlated with the spontaneous activity of the right cerebellum crus II and positively correlated with the spontaneous activity of the right superior frontal cortex, which are inhibition-related brain regions. Furthermore, the microstate results of rest EEG indicated that the corrected duration, occurrence rate, and contribution of Class C, which is related to the anterior default mode network and is considered to be related to subjective representation of one’ own body by combining interoceptive information with affective salience, were significantly positively correlated with the disgust sensitivity level. This data-driven approach provides the first evidence on the intrinsic brain features of disgust sensitivity based on two resting-state brain modalities. The results represent an initial effort to uncover the neurological basis of disgust sensitivity and its connection to psychopathology.
Disgust is a basic emotion of rejection providing an ancestral defensive mechanism against illness. Based on research documenting altered experience of disgust across several psychopathological conditions, we provided a narrative review to address the hypothesis that altered disgust may serve as transdiagnostic criterion of mental illness. Our narrative synthesis of the last decades literature shows that, compared to healthy population, patients with mental disorders exhibit abnormal sensitivity or propensity to disgust in all analyzed dimensions. We also outlined common alterations in brain areas relevant to disgust processing such as the insula and the cortico-basal ganglia network. Our review provides preliminary support to the proposal that altered disgust provides a transdiagnostic index across all the examined mental and personality disorders.
Disgust is a basic emotion of rejection providing an ancestral defensive mechanism against illness. Based on research documenting altered experience of disgust across several psychopathological conditions, we provided a narrative review to address the hypothesis that altered disgust may serve as transdiagnostic criterion of mental illness. Our narrative synthesis of the last decades literature shows that, compared to healthy population, patients with mental disorders exhibit abnormal sensitivity or propensity to disgust in all analyzed dimensions. We also outlined common alterations in brain areas relevant to disgust processing such as the insula and the cortico-basal ganglia network. Our review provides preliminary support to the proposal that altered disgust provides a transdiagnostic index across all the examined mental and personality disorders.
