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This functional magnetic resonance imaging study investigated the disgust- and fear-reactivity of patients suffering from obsessive-compulsive disorder (OCD). Ten OCD patients were scanned while viewing blocks of pictures showing OCD triggers from their personal environment and OCD-irrelevant disgust-inducing, fear-inducing and neutral scenes. Afterwards, the patients rated the intensity of the induced disgust, fear and OCD symptoms. The responses were compared with those of 10 healthy control subjects. The disorder-relevant pictures provoked intense OCD symptoms in the clinical group associated with increased activation in the bilateral prefrontal cortex, the left insula, the right supramarginal gyrus, the left caudate nucleus and the right thalamus. The patients gave higher disgust and fear ratings than the controls for all aversive picture categories. Neural responses towards the disorder-irrelevant disgusting and fear-inducing material included more pronounced insula activation in patients than controls. Summarizing, photos of individual OCD-triggers are an effective means of symptom provocation and activation of the fronto-striato-thalamo-parietal network. The increased insular reactivity of OCD patients during all aversive picture conditions might mirror their susceptibility to experience negative somatic states.

We examined the influence of disgust sensitivity and trait anxiety on disgust processing via functional magnetic resonance imaging. Data of 63 healthy females were combined across four studies, where the same disgusting and affectively neutral pictures had been presented. The disgust pictures, rated as highly repulsive, provoked activation in the occipital cortex, the left prefrontal cortex and both amygdalae. Disgust sensitivity and trait anxiety were positively, and independently from each other, correlated with the activation of the right amygdala. This points to the role of the amygdala as an integrative brain structure, whose activation can be modulated by different affective styles.

We examined whether males and females differ in the intensity and laterality of their hemodynamic responses towards visual disgust and fear stimuli. Forty-one female, and 51 male subjects viewed disgust-inducing, fear-inducing and neutral pictures in an fMRI block design. Self-report data indicated that the target emotions had been elicited successfully with women responding stronger than men. While viewing the fear pictures, which depicted attacks by humans or animals, men exhibited greater activation in the bilateral amygdala and the left fusiform gyrus than women. This response pattern may reflect greater attention from males to cues of aggression in their environment. Further, the lateralization of brain activation was comparable in the two genders during both aversive picture conditions.

Phobic responses are strong emotional reactions towards phobic objects, which can be described as a deficit in the automatic regulation of emotions. Difficulties in the voluntary cognitive control of these emotions suggest a further phobia-specific deficit in effortful emotion regulation mechanisms. The actual study is based on this emotion regulation conceptualization of specific phobias. The aim is to investigate the neural correlates of these two emotion regulation deficits in spider phobics. Sixteen spider phobic females participated in a functional magnetic resonance imaging (fMRI) study in which they were asked to voluntarily up- and down-regulate their emotions elicited by spider and generally aversive pictures with a reappraisal strategy. In line with the hypothesis concerning an automatic emotion regulation deficit, increased activity in the insula and reduced activity in the ventromedial prefrontal cortex was observed. Furthermore, phobia-specific effortful regulation within phobics was associated with altered activity in medial prefrontal cortex areas. Altogether, these results suggest that spider phobic subjects are indeed characterized by a deficit in the automatic as well as the effortful regulation of emotions elicited by phobic compared with aversive stimuli. These two forms of phobic emotion regulation deficits are associated with altered activity in different medial prefrontal cortex subregions.

Findings from several functional magnetic resonance imaging (fMRI) studies implicate the existence of a distinct neural disgust substrate, whereas others support the idea of distributed and integrative brain systems involved in emotional processing. In the present fMRI experiment 12 healthy females viewed pictures from four emotion categories. Two categories were disgust-relevant and depicted contamination or mutilation. The other scenes showed attacks (fear) or were affectively neutral. The two types of disgust elicitors received comparable ratings for disgust, fear and arousal. Both were associated with activation of the occipitotemporal cortex, the amygdala, and the orbitofrontal cortex; insula activity was nonsignificant in the two disgust conditions. Mutilation scenes induced greater inferior parietal activity than contamination scenes, which might mirror their greater capacity to capture attention. Our results are in disagreement with the idea of selective disgust processing at the insula. They point to a network of brain regions involved in the decoding of stimulus salience and the regulation of attention.

The major goal of the present functional magnetic resonance imaging study was to investigate the influence of disgust sensitivity on hemodynamic responses during disgust induction. Fifteen subjects viewed three different film excerpts (duration: 135 s each) with disgust-evoking, threatening and neutral content. The films were presented in a block design with four repetitions of each condition. Afterwards, subjects gave affective ratings for the films and answered the questionnaire for the assessment of disgust sensitivity (QADS, []). The subjects' overall disgust sensitivity was positively related to their experienced disgust, as well as to their prefrontal cortex activation during the disgust condition. Further, there was a positive correlation between subjects' scores on the QADS subscale spoilage/decay and their amygdala activation (r=0.76). This was reasonable since the disgust film clip depicted a cockroach-invasion and the subscale spoilage/decay contains, among others, an item asking for disgust towards cockroaches. The study stresses, in accordance to previous studies, the importance of considering personality traits when studying affective responses in fMRI studies.

Perceiving a first target stimulus (T1) in a rapid serial visual presentation stream results in a transient impairment in detecting a second target (T2). This "attentional blink" is modulated by the emotional relevance of T1 and T2. The present experiment examined the neural underpinnings of the emotional modulation of the attentional blink. Behaviorally, the attentional blink was reduced for emotional T2 while emotional T1 led to a prolonged attentional blink. Using functional magnetic resonance imaging, we observed amygdala activation associated with the reduced attentional blink for emotional T2 in the face of neutral T1. The prolonged attentional blink following emotional T1 was correlated with enhanced activity in a cortical network including the anterior cingulate cortex, the insula and the orbitofrontal cortex. These results suggest that brain areas previously implicated in rather reflexive emotional reactions are responsible for the reduced attentional blink for emotional T2 whereas neural structures previously related to higher level processing of emotional information mediate the prolonged attentional blink following emotional T1.

Inconsistent findings from several functional magnetic resonance imaging (fMRI) studies on fear and disgust raise the question which brain regions are relatively specialized and which are general in the processing of these basic emotions. Some of these inconsistencies could partially be due to inter-individual differences in the experience of the applied emotional stimuli. In the present study, we therefore correlated the participants' individual online reports of fear and disgust with their hemodynamic responses towards each of the fear- and disgust-inducing scenes. Sixty six participants (32 females) took part in the fMRI study. In an event-related design, they saw 50 pictures with different emotional impact (10 neutral, 20 disgust-inducing, 20 fear-inducing). Pictures were presented for 4 s and participants rated each picture online - just after the presentation - on the dimensions disgust and fear among others. The results indicate that the processing of disgust- and fear-inducing pictures involves similar as well as distinct brain regions. Both emotional stimulus categories resulted in activations in the extended occipital cortex, in the prefrontal cortex, and in the amygdala. However, insula activations were only significantly correlated with subjective ratings of disgust, pointing to a specific role of this brain structure in the processing of disgust.

The majority of neuroimaging studies on affective processing have indicated that there are specific brain structures, which are selectively responsive to fear and disgust. Whereas the amygdala is assumed to be fear-related, the insular cortex is most likely involved in disgust processing. Since these findings are mainly a result of studies focusing exclusively either on fear, or on disgust, but rarely on both emotions together, the present experiment explored the neural effects of viewing disgusting and fear-inducing pictures in contrast to neutral pictures. This was done by means of functional magnetic resonance imaging (fMRI) with 19 subjects (nine males, ten females), who also gave affective ratings for the presented pictures. The fear and the disgust pictures were able to induce the target emotions and they received comparable valence and arousal ratings. The processing of both aversive picture types was associated with an increased brain activation in the occipital-temporal lobe, in the prefrontal cortex, and in the thalamus. The amygdala was significantly activated by disgusting, but not by fear-inducing, pictures. Thus, our data are in contrast with the idea of highly emotion-specific brain structures and rather suggest the existence of a common affective circuit.