Common and distinct neurofunctional representations of core and social disgust in the brain: An ALE meta-analysis and MACM characterization

ABSTRACTDisgust represents a multifaceted defensive-avoidance response. On the behavioral level, the response includes withdrawal and a disgust-specific facial expression. While both serve the avoidance of pathogens the latter additionally transmits social-communicative information. Given that common and distinct brain representation of the primary defensive-avoidance response (core disgust) and encoding of the social-communicative signal (social disgust) remain debated we employed neuroimaging meta-analyses to (1) determine brain systems generally engaged in disgust processing, and (2) segregate common and distinct brain systems for core and social disgust. Disgust processing, in general, engaged a bilateral network encompassing the insula, amygdala, occipital and prefrontal regions. Core disgust evoked stronger reactivity in left-lateralized threat detection and defensive response network including amygdala, occipital and frontal regions while social disgust engaged a right-lateralized superior temporal-frontal network engaged in social cognition. Anterior insula, inferior frontal and fusiform regions were commonly engaged during core and social disgust suggesting a common neural basis. We demonstrate a common and separable neural basis of primary disgust responses and encoding of associated social-communicative signals.

The Impact of the Covid-19 Pandemic on Disgust Sensitivity

There have been few tests of whether exposure to naturalistic or experimental disease-threat inductions alter disgust sensitivity, although it has been hypothesized that this should occur as part of disgust’s disease avoidance function. In the current study, we asked Macquarie university students to complete measures of disgust sensitivity, perceived vulnerability to disease (PVD), hand hygiene behavior and impulsivity, during Australia’s Covid-19 pandemic self-quarantine (lockdown) period, in March/April 2020. These data were then compared to earlier Macquarie university, and other local, and overseas student cohorts, to determine if disgust sensitivity and the other measures, were different in the lockdown sample. The most consistent finding in the lockdown sample was of higher core disgust sensitivity (Cohen’s d = 0.4), with some evidence of greater germ aversion on the PVD, and an increase in hand and food-related hygiene, but with little change in impulsivity. The consistency with which greater core disgust sensitivity was observed, suggests exposure to a highly naturalistic disease threat is a plausible cause. Greater disgust sensitivity may have several functional benefits (e.g., hand and food-related hygiene) and may arise implicitly from the threat posed by the Covid-19 pandemic.

The Emotion of Disgust among Medical and Psychology Students

The emotion of disgust evolved as a way to protect oneself from illness and is associated with aspects of disease avoidance. Disgust Scale–Revised (DS-R) (Olatunji et al., 2008) measures the disgust propensity of three kinds of disgust (core, animal reminder, contamination). Contextual factors, such as academic background, might influence DS-R scoring, especially among medical students, where the notion of disease is central. We examined DS-R scoring and the choice of postgraduate studies in medical (n = 94) and psychology (n = 97) students. In an anonymous web-based survey, participants completed the DS-R and a questionnaire including plans for postgraduate studies. Females outnumbered males and scored higher in total DS-R score (p = 0.003). Psychology students scored higher in all three kinds of disgust (p < 0.001 for core disgust and animal reminder, p = 0.069 for contamination disgust), indicating a higher level of disease avoidance. Medical students willing to follow Internal Medicine scored higher in core disgust (p < 0.05), while psychology students willing to study Experimental Psychology scored lower in the animal reminder subscale (p = 0.019 and p < 0.001 for the association between these subscales and the orientation of Medical and Psychology Students, respectively). In conclusion, disgust propensity as rated by DS-R is related to academic background and orientation preferences in postgraduate studies.

The Emotion of Disgust among Medical and Psychology Students

Disgust evolved as a way to protect one&rsquo;s self from illness. DS-R measures disgust propensity of three kinds of disgust (Core, Animal Reminder and Contamination). Although the DS-R scale was refined mainly with young and largely female student population its impact on educational orientation has not been assessed. In the present study we examined the DS-R scoring and the choice of postgraduate studies in medical (n= 94) and psychology (n= 97) students. They responded to an anonymous web-based survey and completed the DS-R and a questionnaire on their demographics and plans for postgraduate studies. Female students outnumbered males (3:1) and scored higher in Total DS-R score (median: 59 vs. 50, p&lt;0.05). Psychology students scored higher in all three kinds of disgust (p&lt;0.05), indicating a higher level of disease avoidance. Medical students willing to follow Internal Medicine scored higher in Core Disgust (p&lt;0.05) while psychology students willing to study Experimental Psychology scored lower in Animal Reminder subscale (p&lt;0.001). Also, the higher the psychology students scored in Core Disgust scale the higher was the probability to choose Experimental Psychology. In conclusion, disgust propensity as rated by DS-R differentiates medical from psychology students and is also related to orientation preferences in postgraduate studies.

The Mediational Roles of Law of Contagion and Threat Estimations in the Relation Between Disgust and Contamination-based OCD Symptoms

Objectives: The law of contagion is one of the sympathetic of magic principles and is a cognitive distortion related to disgust. To explain how disgust can lead to contamination Obsessive-Compulsive Disorder (OCD) symptoms, this study assumes that the emotion of disgust can activate the law of contagion, which in turn may motivate threat estimations that finally results in OCD symptoms. Methods: This study has a correlational research design. Participants were 495 students (59% women) from Olum Tahghighat University that recruited through convenience sampling. All the participants completed all the questionnaires in the same order: Threat estimation scenarios, the Vancouver Obsessional Compulsive Inventory Contamination Scale (VOCI-C), negative-spiritual contagion subscale from Contagion Sensitivity Scale (CSS), and core disgust subscale from Disgust Scale (DS). This model was examined through Structural Equation Modeling (SEM). Results: The finding revealed that the proposed model had a good fit based on reported indices: χ2, CMIN/DF, GFI, CFI, AGFI, RMSEA. Conclusion: There are mediational roles for the law of contagion and threat estimations in the relation between disgust and OCD symptoms. The proposed psychopathological model can help to promote the disgust theory in OCD and may have implications for cognitive behavioral therapy.

Deconstructing Judicial Expressions of Disgust

Though much has been written about judicial anger and other emotional displays from the judicial bench, comparatively little attention has been paid to disgust. This particular emotion does not seem to be expressed or reflected by judges as much as other negative sentiments or feelings; “disgust” also has an emotional resonance that we might not associate with things like anger and sadness, and exists in more than one form. Focusing on a sample of cases in which judges have used the term, the article questions what type of disgust is being shown (“core” disgust or “socio-moral” disgust), whether the emotion is experienced or articulated, and what the significance is of using the word “disgust” in the judicial narrative. Si bien mucho se ha escrito sobre la ira judicial y otras manifestaciones de emoción por parte de la judicatura, se ha prestado relativamente poca atención a la repugnancia. Parece que los jueces no suelen expresar o reflejar dicha emoción tan a menudo como otros sentimientos negativos; la “repugnancia” también tiene un eco emocional que, posiblemente, no relacionamos con la ira y la tristeza, y existe en varias formas. Centrándonos en una muestra de casos en los que los jueces han utilizado el término, en el artículo cuestionamos qué tipo de repugnancia se está mostrando (repugnancia “básica” o repugnancia “socio-moral”), si la emoción está siendo experimentada o articulada, y cuál es el significado del uso de la palabra “repugnancia” en la narrativa judicial.

Disgust Proneness and Personal Space in Children

Individuals vary in their personal space (PS) size as reflected by the preferred distance to another person during social interactions. A previous study with adults showed that pathogen-relevant disgust proneness (DP) predicted PS magnitude. The present study investigated whether this association between DP and PS already exists in 8- to 12-year-old children (144 girls, 101 boys). The children answered a disgust questionnaire with the two trait dimensions “core disgust (contact with spoiled food and poor hygiene) and “death-relevant disgust” (imagined contact with dead and dying organisms). PS magnitude was assessed with a paper–pencil measure (drawing a PS bubble; Experiment 1) or with the stop-distance task (preferred distance to an approaching woman or man; Experiment 2). In both experiments, only death-related disgust predicted PS magnitude and only if the approaching person was male. The current study questions the relevance of pathogen-related disgust in children for regulating interpersonal distance.

Worm in the Pudding Cup

Drawing on insights offered by Richard Beck in Unclean: Meditations on Purity, Hospitality, and Mortality (Beck 2011), I explore several categories of disgust. Girard incorporates sociomoral disgust into his theoretical reflections; however, core disgust and animal-reminder disgust are discrete forms of revulsion not recognized as such by Girard. Arguing that these merit special attention, I argue that Girard’s theory is made more compelling, not less, when we attend to foul elements that ooze from around the edges of his theory despite his effort to contain them under the sign of sacrifice. Making this seepage a topic of discussion is like taking the lid off a carton long forgotten at the back of the refrigerator. Yes, the mold so revealed is repulsive; however, as Alexander Fleming found when he discovered penicillin in mold growing in a neglected petri dish in his lab, that which disgusts us can also save us.

Core disgust is attenuated by ingroup relations

We present the first experimental evidence to our knowledge that ingroup relations attenuate core disgust and that this helps explain the ability of groups to coact. In study 1, 45 student participants smelled a sweaty t-shirt bearing the logo of another university, with either their student identity (ingroup condition), their specific university identity (outgroup condition), or their personal identity (interpersonal condition) made salient. Self-reported disgust was lower in the ingroup condition than in the other conditions, and disgust mediated the relationship between condition and willingness to interact with target. In study 2, 90 student participants smelled a sweaty target t-shirt bearing either the logo of their own university, another university, or no logo, with either their student identity or their specific university identity made salient. Walking time to wash hands and pumps of soap indicated that disgust was lower where the relationship between participant and target was ingroup rather than outgroup or ambivalent (no logo).

Disgust, Moral Disgust, and Morality

This paper calls into question the idea that moral disgust is usefully regarded as a form of genuine disgust. This hypothesis is questionable even if, as some have argued, the spread of moral norms through a community makes use of signaling mechanisms that are central to core disgust. The signaling system is just one part of disgust, and may well be completely separable from it. Moreover, there is plausibly a significant difference between the cognitive scientist’s concept of an emotion and the everyday notion of that emotion. Finally, even if, as this paper contests, some form of disgust were directly elicited by the moral wrongness of certain kinds of behavior, research on the socio-moral elicitors of the disgust mechanism would still be unlikely to shed much direct light on the nature or content of morality.