Preferential responses in amygdala and insula during presentation of facial contempt and disgust

Trait Anxiety Influences Negative Affect-modulated Distribution of Visuospatial Attention

Visuospatial attention allows humans to selectively gate and prioritize visual (including salient, emotional) information for efficiently navigating natural visual environments. As emotions have been known to influence attentional performance, we asked if emotions also modulate the spatial distribution of visual attention and whether any such effect was further associated with individual differences in anxiety. Participants (n = 28) discriminated the orientation of target Gabor patches co-presented with distractors, speedily and accurately. The key manipulation was randomly presenting a task-irrelevant face emotion prime briefly (50 ms), conveying Neutral/Disgust/Scrambled (Null) emotion signal 150 ms preceding the target patches. We calculated attention gradient (change in negative inverse attentional efficiency with unit change in distance from the source of emotion signal) as a metric to answer our questions. Specifically, the Disgust signal modulated the direction of attention gradients differentially in individuals with varying degrees of trait - anxiety, such that the gradients correlated negatively with individual trait-anxiety scores. This implies spatial shifts in Disgust-signalled visual attention with varying trait - anxiety levels. Neutral yielded attention gradients comparable to Scrambled, implying no specific effect of this signal and there was no association with anxiety levels in both. No correlation was observed between state - anxiety and the emotion-cued attention gradients. In sum, the results suggest that individual trait - anxiety levels influence the effect of negative and physiologically arousing emotion signals (e.g., Disgust) on the spatial distribution of visual attention. The findings could be of relevance for understanding biases in visual behaviour underlying affective states and disorders.

Food as a key disgust elicitor in infancy and childhood: Previous research and opportunities for future study

Disliked foods may have important value in the study of the development of disgust. The current review draws from literature across disciplines, including theories of disgust and studies of the development of eating behavior and food preferences, to highlight food as an important category of disgust responses across a wide age range, including children as young as 3 years old and adults. Children's disgust responses to certain types of food are considered to be both innate and culturally constrained behaviors, and their perceptions of other people's food choices indicate potential links between foods and cultural groups. We end by discussing several ongoing and future research areas, including connections between disgust responses and food rejection in infancy and children's food rejection behaviors across cultures.

Common and distinct neurofunctional representations of core and social disgust in the brain: Coordinate-based and network meta-analyses

Disgust 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 shared neurofunctional basis. We demonstrate a common and distinct neural basis of primary disgust responses and encoding of associated social-communicative signals.

Ventromedial prefrontal cortex activity differentiates sick from healthy faces: Associations with inflammatory responses and disease avoidance motivation

BACKGROUND

Humans are able to discern the health status of others using olfactory and visual cues, and subsequently shift behavior to make infection less likely. However, little is known about how this process occurs. The present study examined the neural regions involved in differentiating healthy from sick individuals using visual cues.

METHODS

While undergoing a functional magnetic resonance imaging scan, participants (N = 42) viewed facial photos of 30 individuals (targets) who had been injected with an inflammatory challenge--low-dose endotoxin (i.e., sick) or placebo (i.e., healthy), and rated how much they liked each face. We examined regions implicated in processing either threat (amygdala, anterior insula) or cues that signal safety (ventromedial prefrontal cortex [VMPFC]), and how this activity related to their liking of targets and cytokine levels (interleukin-6, tumor necrosis factor-α) exhibited by the targets.

RESULTS

Photos of sick faces were rated as less likeable compared to healthy faces, and the least liked faces were those individuals with the greatest inflammatory response. While threat-related regions were not significantly active in response to viewing sick faces, the VMPFC was more active in response to viewing healthy (vs. sick) faces. Follow-up analyses revealed that participants tended to have lower VMPFC activity when viewing the least liked faces and the faces of those with the greatest inflammatory response.

CONCLUSIONS

This work builds on prior work implicating the VMPFC in signaling the presence of safe, non-threatening visual stimuli, and suggests the VMPFC may be sensitive to cues signaling relative safety in the context of pathogen threats.

Facial Emotion Recognition in Obesity and in Fibromyalgia: A Systematic Review

Facial emotion recognition (FER) is extensively investigated in psychological sciences in healthy individuals and clinical conditions. In this paper, we analyzed those studies in which FER was assessed in the case of obesity or fibromyalgia, in relation to the levels of alexithymia. Crucially, these two conditions frequently co-occur; however, no study has explored FER considering both fibromyalgia and obesity. Studies were identified using the electronic search engine of PubMed. The last research was run on 23 July 2021. Two independent lists were generated for the two clinical conditions. Six records were reviewed about obesity, while three records about fibromyalgia. The evidence relative to FER in obesity was not conclusive, whereas the evidence about an altered FER in fibromyalgia seemed more straightforward. Moreover, the role of alexithymia on FER in these clinical conditions was not extensively investigated. In our discussion, we highlighted those factors that should be carefully addressed in investigating FER in these clinical conditions. Moreover, we underlined methodological criticisms that should be overcome in future research.

Facial Emotion Recognition and Executive Functions in Fibromyalgia

OBJECTIVE

The ability to accurately identify facial expressions of emotions is crucial in human interaction. Although a previous study suggested deficient emotional face recognition in patients with fibromyalgia, not much is known about the origin of this impairment. Against this background, the present study investigated the role of executive functions. Executive functions refer to cognitive control mechanisms enabling implementation and coordination of basic mental operations. Deficits in this domain are prevalent in fibromyalgia.

METHODS

Fifty-two fibromyalgia patients and thirty-two healthy individuals completed the Ekman-60 Faces Test, which requires classification of facial displays of happiness, sadness, anger, fear, surprise, and disgust. They also completed eight tasks assessing the executive function components of shifting, updating, and inhibition. Effects of comorbid depression and anxiety disorders, as well as medication use, were tested in stratified analyses of patient subgroups.

RESULTS

Patients made more errors overall than controls in classifying the emotional expressions. Moreover, their recognition accuracy correlated positively with performance on most of the executive function tasks. Emotion recognition did not vary as a function of comorbid psychiatric disorders or medication use.

CONCLUSIONS

The study supports impaired facial emotion recognition in fibromyalgia, which may contribute to the interaction problems and poor social functioning characterizing this condition. Facial emotion recognition is regarded as a complex process, which may be particularly reliant on efficient coordination of various basic operations by executive functions. As such, the correlations between cognitive task performance and recognition accuracy suggest that deficits in higher cognitive functions underlie impaired emotional communication in fibromyalgia.

Facial expression recognition: A meta-analytic review of theoretical models and neuroimaging evidence

Discrimination of facial expressions is an elementary function of the human brain. While the way emotions are represented in the brain has long been debated, common and specific neural representations in recognition of facial expressions are also complicated. To examine brain organizations and asymmetry on discrete and dimensional facial emotions, we conducted an activation likelihood estimation meta-analysis and meta-analytic connectivity modelling on 141 studies with a total of 3138 participants. We found consistent engagement of the amygdala and a common set of brain networks across discrete and dimensional emotions. The left-hemisphere dominance of the amygdala and AI across categories of facial expression, but category-specific lateralization of the vmPFC, suggesting a flexibly asymmetrical neural representations of facial expression recognition. These results converge to characteristic activation and connectivity patterns across discrete and dimensional emotion categories in recognition of facial expressions. Our findings provide the first quantitatively meta-analytic brain network-based evidence supportive of the psychological constructionist hypothesis in facial expression recognition.

Effects of low- and high-intensity exercise on emotional face processing: an fMRI face-matching study

Physical exercise has positive effects on mood and it reduces clinical depression and states of anxiety. While previous work mostly used subjective measures to study the effect of exercise upon emotions, this study for the first time employed blood oxygen level dependent functional magnetic resonance imaging (fMRI) to unravel associated neuronal changes of the emotional face-processing network in response to acute exercise. A total of 25 male athletes underwent fitness assessments to define two standardized 30 min exercise interventions (low and high intensity). The Positive and Negative Affect Schedule (PANAS) was completed pre- and post-exercise and neuronal responses to neutral, happy and fearful facial expressions were determined using an fMRI-based face-matching paradigm. Complete data sets were acquired in 21 participants (mean age, 27.2 ± 4.2 years). Both exercise interventions induced significant increases of the PANAS positive affect scale. Modulations of brain activation patterns following acute exercise were found only for fearful facial stimuli vs forms: reduced brain activation in posterior cingulate cortex/precuneus for the low condition and reduced activity in caudate nucleus and ventral anterior putamen for the high condition. In conclusion, this study provides first in vivo evidence that acute strenuous exercise interferes with emotional face-processing brain regions in an emotion type-specific manner.

Childhood Maltreatment, Limbic Dysfunction, Resilience, and Psychiatric Symptoms

Previous research has indicated that childhood maltreatment is predictive of psychiatric symptoms in adulthood. Among the potential intervening factors in this relationship are affective reactions in the victims, neurodevelopmental problems, and resilience. The purpose of this study was to test, in a nonclinical low-risk sample, an integrative developmentally based psychoneurological model of the roles of limbic system dysfunction, shame and guilt, and resiliency as potential intervening variables between childhood maltreatment and adult psychiatric symptoms. Also of interest was whether there were gender-specific pathways from maltreatment to symptoms. Based on the results of preliminary analyses, several regressions were conducted separately by gender, entering the different forms of parental aggression at Step 1, resilience at Step 2, the resilience by parental aggression interaction term at Step 3, shame and guilt at Step 4, and limbic dysfunction at Step 5, as predictors of psychiatric symptoms. Analyses indicated that both maternal psychological maltreatment and paternal physical maltreatment were predictive of total psychiatric symptomatology in adulthood, with shame mediating the relationship in women and guilt mediating it in men, limbic system symptoms mediating the relationship in both genders, and trait resilience moderating the relationship in both genders.

Self-disgust as a potential mechanism underlying the association between PTSD and suicide risk

Suicide risk is highly prevalent among individuals with posttraumatic stress disorder (PTSD). Self-disgust, defined as disgust directed internally and comprised of disgust with oneself (disgusting self) and with one's behaviors (disgusting ways), may impact this increased risk. The present study examined self-disgust as a putative mechanism linking PTSD symptoms with suicide risk. A sample of 347 trauma-exposed undergraduates completed measures of PTSD symptoms, suicide risk, self-disgust, and depressive symptoms. Controlling for depressive symptoms, a process model indicated PTSD symptoms were positively linked to suicide risk via increased disgusting self but not disgusting ways. Process models examining individual PTSD symptom clusters revealed positive, indirect links between all PTSD symptom clusters except alterations in arousal and reactivity and suicide risk via disgusting self. These findings expand on growing literature documenting the importance of self-disgust in trauma-related pathology by identifying connections with suicide risk. Future directions and clinical considerations are discussed.

Cortico-limbic connectivity in MAOA-L carriers is vulnerable to acute tryptophan depletion

INTRODUCTION

A gene-environment interaction between expression genotypes of the monoamine oxidase A (MAOA) and adverse childhood experience increases the risk of antisocial behavior. However, the neural underpinnings of this interaction remain uninvestigated. A cortico-limbic circuit involving the prefrontal cortex (PFC) and the amygdala is central to the suppression of aggressive impulses and is modulated by serotonin (5-HT). MAOA genotypes may modulate the vulnerability of this circuit and increase the risk for emotion regulation deficits after specific life events. Acute tryptophan depletion (ATD) challenges 5-HT regulation and may identify vulnerable neuronal circuits, contributing to the gene-environment interaction.

METHODS

Functional magnetic resonance imaging measured the resting-state state activity in 64 healthy males in a double-blind, placebo-controlled study. Cortical maps of amygdala correlation identified the impact of ATD and its interaction with low- (MAOA-L) and high-expression variants (MAOA-H) of MAOA on cortico-limbic connectivity.

RESULTS

Across all Regions of Interest (ROIs) exhibiting an ATD effect on cortico-limbic connectivity, MAOA-L carriers were more susceptible to ATD than MAOA-H carriers. In particular, the MAOA-L group exhibited a larger reduction of amygdala connectivity with the right prefrontal cortex and a larger increase of amygdala connectivity with the insula and dorsal PCC.

CONCLUSION

MAOA-L carriers were more susceptable to a central 5-HT challenge in cortico-limbic networks. Such vulnerability of the cortical serotonergic system may contribute to the emergence of antisocial behavior after systemic challenges, observed as gene-environment interaction. Hum Brain Mapp 38:1622-1635, 2017. © 2016 Wiley Periodicals, Inc.

How the brain processes violations of the grammatical norm: An fMRI study

Native speakers of Dutch do not always adhere to prescriptive grammar rules in their daily speech. These grammatical norm violations can elicit emotional reactions in language purists, mostly high-educated people, who claim that for them these constructions are truly ungrammatical. However, linguists generally assume that grammatical norm violations are in fact truly grammatical, especially when they occur frequently in a language. In an fMRI study we investigated the processing of grammatical norm violations in the brains of language purists, and compared them with truly grammatical and truly ungrammatical sentences. Grammatical norm violations were found to be unique in that their processing resembled not only the processing of truly grammatical sentences (in left medial Superior Frontal Gyrus and Angular Gyrus), but also that of truly ungrammatical sentences (in Inferior Frontal Gyrus), despite what theories of grammar would usually lead us to believe.

Group Membership Modulates the Neural Circuitry Underlying Third Party Punishment

This research aims to explore the neural correlates involved in altruistic punishment, parochial altruism and anti-social punishment, using the Third-Party Punishment (TPP) game. In particular, this study considered these punishment behaviors in in-group vs. out-group game settings, to compare how people behave with members of their own national group and with members of another national group. The results showed that participants act altruistically to protect in-group members. This study indicates that norm violation in in-group (but not in out-group) settings results in increased activity in the medial prefrontal cortex and temporo-parietal junction, brain regions involved in the mentalizing network, as the third-party attempts to understand or justify in-group members' behavior. Finally, exploratory analysis during anti-social punishment behavior showed brain activation recruitment of the ventromedial prefrontal cortex, an area associated with altered regulation of emotions.

Association between Ability Emotional Intelligence and Left Insula during Social Judgment of Facial Emotions

The human ability of identifying, processing and regulating emotions from social stimuli is generally referred as Emotional Intelligence (EI). Within EI, Ability EI identifies a performance measure assessing individual skills at perceiving, using, understanding and managing emotions. Previous models suggest that a brain "somatic marker circuitry" (SMC) sustains emotional sub-processes included in EI. Three primary brain regions are included: the amygdala, the insula and the ventromedial prefrontal cortex (vmPFC). Here, our aim was to investigate the relationship between Ability EI scores and SMC activity during social judgment of emotional faces. Sixty-three healthy subjects completed a test measuring Ability EI and underwent fMRI during a social decision task (i.e. approach or avoid) about emotional faces with different facial expressions. Imaging data revealed that EI scores are associated with left insula activity during social judgment of emotional faces as a function of facial expression. Specifically, higher EI scores are associated with greater left insula activity during social judgment of fearful faces but also with lower activity of this region during social judgment of angry faces. These findings indicate that the association between Ability EI and the SMC activity during social behavior is region- and emotion-specific.

Temporal estimation of threatening stimuli in social anxiety disorder: investigation of the effects of state anxiety and fearfulness

BACKGROUND AND OBJECTIVES

Prior studies suggest that particularly negative emotional events tend to be experienced as temporally dilated. Perceptual characteristics of the threat cue (averted or directed angry face), state as well as individual anxiety levels have been shown to contribute to the temporal distortions, but the interplay between these factors is not well understood. The present study investigated the relative contributions of these factors in a first study using clinical sample with social anxiety disorder (SAD) and healthy controls (HC).

METHODS

Participants performed a temporal bisection task (TBT) before and after a stress provocation phase, which served to induce state anxiety. During the TBT task, angry and neutral faces with averted vs. direct gaze were presented for the length of 600, 800, 1000, 1200, 1400, 1600 ms, and judged regarding their similarity to the standard durations.

RESULTS

A temporal overestimation effect for angry vs. neutral facial expressions was evident in both the HC and the SAD groups. An effect of experimentally induced state anxiety was evident solely in the SAD group, reflected in an overall increased temporal overestimation of angry vs. neutral expressions following the mood manipulation.

LIMITATIONS

The clinical sample may represent a high-functioning group, as the study was conducted on college students. Replication in more heterogeneous SAD samples is needed in order to draw further conclusions.

CONCLUSIONS

These results may be relevant for the understanding of the etiology and maintenance of SAD and potentially for the development of novel intervention methods.

Investigating the brain basis of facial expression perception using multi-voxel pattern analysis

Humans can readily decode emotion expressions from faces and perceive them in a categorical manner. The model by Haxby and colleagues proposes a number of different brain regions with each taking over specific roles in face processing. One key question is how these regions directly compare to one another in successfully discriminating between various emotional facial expressions. To address this issue, we compared the predictive accuracy of all key regions from the Haxby model using multi-voxel pattern analysis (MVPA) of functional magnetic resonance imaging (fMRI) data. Regions of interest were extracted using independent meta-analytical data. Participants viewed four classes of facial expressions (happy, angry, fearful and neutral) in an event-related fMRI design, while performing an orthogonal gender recognition task. Activity in all regions allowed for robust above-chance predictions. When directly comparing the regions to one another, fusiform gyrus and superior temporal sulcus (STS) showed highest accuracies. These results underscore the role of the fusiform gyrus as a key region in perception of facial expressions, alongside STS. The study suggests the need for further specification of the relative role of the various brain areas involved in the perception of facial expression. Face processing appears to rely on more interactive and functionally overlapping neural mechanisms than previously conceptualised.

Theory of mind and emotional functioning in fibromyalgia syndrome: an investigation of the relationship between social cognition and executive function

Background

Fibromyalgia (FM) is a syndrome primarily characterised by chronic, widespread musculoskeletal pain. In the aetiology of this syndrome a crucial role is played by complex interactions among biological, genetic, psychological, and socio-cultural factors. Recently, researchers have started to explore emotional functioning in FM, with their attention focused on alexithymia, a personality construct that affects the regulation of a person’s own emotions. On the other hand, the detection and experience of emotional signals from other people have only been sparsely investigated in FM syndrome and no studies have investigated the ability to represent other people’s mental states (i.e. Theory of Mind, ToM) in these patients. Here we present the first study investigating a large set of social-cognitive abilities, and the possible relationships between these abilities and the performance on executive-function tasks, in a homogenous sample of patients with FM.

Methodology

Forty women with FM and forty-one healthy women matched for education and age were involved in the study. Social cognition was assessed with a set of validated experimental tasks. Measures of executive function were used to test the correlations between this dimension and the social-cognitive profile of patients with FM. Relationships between social-cognitive abilities and demographic, clinical and psychological variables were also investigated.

Principal Findings

Patients with FM have impairments both in the regulation of their own affect and in the recognition of other’s emotions, as well as in representing other people’s mental states. No significant correlations were found between social cognition tasks and the subcomponents of the executive function that were analysed.

Conclusions

The results show the presence of several impairments in social cognition skills in patients with FM, which are largely independent of both executive function deficits and symptoms of psychological distress. The impairments reported highlight the importance of adequately assessing ToM and emotional functioning in clinical practice.

Recognition of facially expressed emotions in patients with fibromyalgia syndrome

The study investigated the ability to identify facially expressed emotions in fibromyalgia syndrome (FMS) and its association with clinical parameters. Thirty-five FMS patients and 35 healthy controls accomplished a face recognition task. Additionally, pain severity, alexithymia, depression, anxiety, psychiatric co-morbidity and medication use were assessed. The patients displayed reduced task performance in terms of more misclassifications of emotional expressions than controls. Pain severity, alexithymia, depression and anxiety were inversely related to recognition performance, with pain severity accounting for the largest portion of test score variance. Psychiatric co-morbidity and medication had no impact on performance. The study documented impaired emotion recognition in FMS, which may contribute to the interpersonal difficulties and reduced social functioning related to this condition. As potential mechanisms mediating the occurrence of the deficits, altered affective processing due to interoceptive impairment as well as interference of central nervous nociceptive activity with cognitive and emotional processing are discussed.

Dynamical predictions of insular hubs for social cognition and their application to stroke

The insular cortex (IC) is considered a rich hub for context-sensitive emotions/social cognition. Patients with focal IC stroke provide unique opportunities to study socio-emotional processes. Nevertheless, Couto et al. (2013b) have recently reported controversial results regarding IC involvement in emotion and social cognition. Similarly, patients with similar lesions show high functional variability, ranging from almost totally preserved to strongly impaired behavior. Critical evidence suggests that the variability of these patients in the above domains can be explained by enhanced neuroplasticity, compensatory processes, and functional remapping after stroke. Therefore, socio-emotional processes would depend on long-distance connections between the IC and frontotemporal regions. We propose that predictive coding and effective connectivity represent a novel approach to explore functional connectivity and assess compensatory, contralateral, and subsidiary network differences among focal stroke patients. This approach would help explain why socio-emotional performance is so variable within this population.

Excessive disgust caused by brain lesions or temporary inactivations: mapping hotspots of the nucleus accumbens and ventral pallidum

Disgust is a prototypical type of negative affect. In animal models of excessive disgust, only a few brain sites are known in which localized dysfunction (lesions or neural inactivations) can induce intense 'disgust reactions' (e.g. gapes) to a normally pleasant sensation such as sweetness. Here, we aimed to map forebrain candidates more precisely, to identify where either local neuronal damage (excitotoxin lesions) or local pharmacological inactivation (muscimol/baclofen microinjections) caused rats to show excessive sensory disgust reactions to sucrose. Our study compared subregions of the nucleus accumbens shell, ventral pallidum, lateral hypothalamus, and adjacent extended amygdala. The results indicated that the posterior half of the ventral pallidum was the only forebrain site where intense sensory disgust gapes in response to sucrose were induced by both lesions and temporary inactivations (this site was previously identified as a hedonic hotspot for enhancements of sweetness 'liking'). By comparison, for the nucleus accumbens, temporary GABA inactivations in the caudal half of the medial shell also generated sensory disgust, but lesions never did at any site. Furthermore, even inactivations failed to induce disgust in the rostral half of the accumbens shell (which also contains a hedonic hotspot). In other structures, neither lesions nor inactivations induced disgust as long as the posterior ventral pallidum remained spared. We conclude that the posterior ventral pallidum is an especially crucial hotspot for producing excessive sensory disgust by local pharmacological/lesion dysfunction. By comparison, the nucleus accumbens appears to segregate sites for pharmacological disgust induction and hedonic enhancement into separate posterior and rostral halves of the medial shell.

Delineating the Influence of Emotion and Reason on Morality and Punishment

The present article examines the available literature on the association between emotion, conscious reasoning, morality, and punishment. Although conscious reasoning has traditionally been implicated in moral judgment, contemporary research suggests that emotions play a primary role in moral judgment. This article reviews the different lines of evidence supporting the role of emotion in moral decision-making. Disgust seems to be unique from other emotions in its ability to influence moral judgment. Immorality often elicits disgust, individuals sensitive to experiencing disgust tend to make more severe moral judgments, and experimental disgust inductions can influence judgments about moral violations. However, the extent to which the emotion-moral judgment association extends to decisions about punishment remains unclear. This review considers various concepts, including moral outrage, responsibility, and blameworthiness that may influence the extent to which emotion informs punishment decisions. The implications of these findings for current thinking on morality and punishment, and future directions for research are discussed.

Real-time functional MRI neurofeedback: a tool for psychiatry

PURPOSE OF REVIEW

The aim of this review is to provide a critical overview of recent research in the field of neuroscientific and clinical application of real-time functional MRI neurofeedback (rtfMRI-nf).

RECENT FINDINGS

RtfMRI-nf allows self-regulating activity in circumscribed brain areas and brain systems. Furthermore, the learned regulation of brain activity has an influence on specific behaviors organized by the regulated brain regions. Patients with mental disorders show abnormal activity in certain regions, and simultaneous control of these regions using rtfMRI-nf may affect the symptoms of related behavioral disorders.

SUMMARY

The promising results in clinical application indicate that rtfMRI-nf and other metabolic neurofeedback, such as near-infrared spectroscopy, might become a potential therapeutic tool. Further research is still required to examine whether rtfMRI-nf is a useful tool for psychiatry because there is still lack of knowledge about the neural function of certain brain systems and about neuronal markers for specific mental illnesses.

Threat processing in generalized social phobia: an investigation of interpretation biases in ambiguous facial affect

Facial affect is one of the most important information sources during the course of social interactions, but it is susceptible to distortion due to the complex and dynamic nature. Socially anxious individuals have been shown to exhibit alterations in the processing of social information, such as an attentional and interpretative bias toward threatening information. This may be one of the key factors contributing to the development and maintenance of anxious psychopathology. The aim of the current study was to investigate whether a threat-related interpretation bias is evident for ambiguous facial stimuli in a population of individuals with a generalized Social Anxiety Disorder (gSAD) as compared to healthy controls. Participants judged ambiguous happy/fearful, angry/fearful and angry/happy blends varying in intensity and rated the predominant affective expression. The results obtained in this study do not indicate that gSAD is associated with a biased interpretation of ambiguous facial affect.

Successful contextual integration of loose mental associations as evidenced by emotional conflict-processing

Often we cannot resist emotional distraction, because emotions capture our attention. For example, in TV-commercials, tempting emotional voices add an emotional expression to a formerly neutral product. Here, we used a Stroop-like conflict paradigm as a tool to investigate whether emotional capture results in contextual integration of loose mental associations. Specifically, we tested whether the associatively connected meaning of an ignored auditory emotion with a non-emotional neutral visual target would yield a modulation of activation sensitive to emotional conflict in the brain. In an fMRI-study, nineteen participants detected the presence or absence of a little worm hidden in the picture of an apple, while ignoring a voice with an emotional sound of taste (delicious/disgusting). Our results indicate a modulation due to emotional conflict, pronounced most strongly when processing conflict in the context of disgust (conflict: disgust/no-worm vs. no conflict: disgust/worm). For conflict in the context of disgust, insula activity was increased, with activity correlating positively with reaction time in the conflict case. Conflict in the context of deliciousness resulted in increased amygdala activation, possibly due to the resulting “negative” emotion in incongruent versus congruent combinations. These results indicate that our associative stimulus-combinations showed a conflict-dependent modulation of activity in emotional brain areas. This shows that the emotional sounds were successfully contextually integrated with the loosely associated neutral pictures.

Changes in the amygdala produced by viewing strabismic eyes

PURPOSE

The aim of this study was to look for the response to strabismus images in the limbic network (amygdala, hippocampus, parahippocampus) of healthy volunteers and to compare it with their reaction to viewing normal eyes.

DESIGN

Prospective, observational study.

PARTICIPANTS

Thirty-one healthy volunteers underwent functional magnetic resonance imaging (fMRI).

METHODS

Functional magnetic resonance imaging data and blood oxygen level-dependent signal changes were analyzed using the BrainVoyager QX software package (Brain Innovation, Maastricht, The Netherlands).

MAIN OUTCOME MEASURES

Responses to viewing strabismus images were compared with those observed while viewing normal eye images.

RESULTS

Strabismus images led to significant activation of the amygdala, hippocampus, parahippocampal, and fusiform gyri in 30 of 31 subjects compared with normal eye images, indicating a negative emotional response.

CONCLUSIONS

These fMRI results confirm that strabismus influences organically not only the patient with nonparallel eyes but also observers. Treatment of strabismus therefore changes the interpersonal dynamic for patients with strabismus on a demonstrable organic basis.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Sex differences in neural activation to ambiguous facial expression in happy and sad context

Functional magnetic resonance imaging (fMRI) was used to investigate brain activation associated with a facial expression identification task (stimuli were full emotional, half emotional, or ambiguous in both happy and sad context) in 10 men and 10 women, fMRI assessment revealed significant interaction of sex x context in the right putamen for the ambiguous faces. Women showed a greater BOLD response to ambiguous facial expression in the sad context than in the happy context, while men showed a greater response in the happy context. Further, women showed a greater BOLD response than did men to ambiguous facial expression in the sad context, while men showed a greater response than women in the happy context. These results suggest that sad and happy context differentially modulate right putamen activation related to processing of ambiguous facial expression in men and women.

Current Emotion Research in Behavioral Neuroscience: The Role(s) of the Amygdala

Substantial advances in our understanding of the neural bases of emotional processing have been made over the past decades. Overall, studies in humans and other animals highlight the key role of the amygdala in the detection and evaluation of stimuli with affective value. Nonetheless, contradictory findings have been reported, especially in terms of the exact role of this structure in the processing of different emotions, giving rise to different neural models of emotion. For instance, although the amygdala has traditionally been considered as exclusively involved in fear (and possibly anger), more recent work suggests that it may be important for processing other types of emotions, and even nonemotional information. A review of the main findings in this field is presented here, together with some of the hypotheses that have been put forward to interpret this literature and explain its inconsistencies.

Neural mechanisms underlying the effects of face-based affective signals on memory for faces: a tentative model

In our daily lives, we form some impressions of other people. Although those impressions are affected by many factors, face-based affective signals such as facial expression, facial attractiveness, or trustworthiness are important. Previous psychological studies have demonstrated the impact of facial impressions on remembering other people, but little is known about the neural mechanisms underlying this psychological process. The purpose of this article is to review recent functional MRI (fMRI) studies to investigate the effects of face-based affective signals including facial expression, facial attractiveness, and trustworthiness on memory for faces, and to propose a tentative concept for understanding this affective-cognitive interaction. On the basis of the aforementioned research, three brain regions are potentially involved in the processing of face-based affective signals. The first candidate is the amygdala, where activity is generally modulated by both affectively positive and negative signals from faces. Activity in the orbitofrontal cortex (OFC), as the second candidate, increases as a function of perceived positive signals from faces; whereas activity in the insular cortex, as the third candidate, reflects a function of face-based negative signals. In addition, neuroscientific studies have reported that the three regions are functionally connected to the memory-related hippocampal regions. These findings suggest that the effects of face-based affective signals on memory for faces could be modulated by interactions between the regions associated with the processing of face-based affective signals and the hippocampus as a memory-related region.

The centre of the brain: topographical model of motor, cognitive, affective, and somatosensory functions of the basal ganglia

The basal ganglia have traditionally been viewed as motor processing nuclei; however, functional neuroimaging evidence has implicated these structures in more complex cognitive and affective processes that are fundamental for a range of human activities. Using quantitative meta-analysis methods we assessed the functional subdivisions of basal ganglia nuclei in relation to motor (body and eye movements), cognitive (working-memory and executive), affective (emotion and reward) and somatosensory functions in healthy participants. We document affective processes in the anterior parts of the caudate head with the most overlap within the left hemisphere. Cognitive processes showed the most widespread response, whereas motor processes occupied more central structures. On the basis of these demonstrated functional roles of the basal ganglia, we provide a new comprehensive topographical model of these nuclei and insight into how they are linked to a wide range of behaviors.

Acquired self-control of insula cortex modulates emotion recognition and brain network connectivity in schizophrenia

Real-time functional magnetic resonance imaging (rtfMRI) is a novel technique that has allowed subjects to achieve self-regulation of circumscribed brain regions. Despite its anticipated therapeutic benefits, there is no report on successful application of this technique in psychiatric populations. The objectives of the present study were to train schizophrenia patients to achieve volitional control of bilateral anterior insula cortex on multiple days, and to explore the effect of learned self-regulation on face emotion recognition (an extensively studied deficit in schizophrenia) and on brain network connectivity. Nine patients with schizophrenia were trained to regulate the hemodynamic response in bilateral anterior insula with contingent rtfMRI neurofeedback, through a 2-weeks training. At the end of the training stage, patients performed a face emotion recognition task to explore behavioral effects of learned self-regulation. A learning effect in self-regulation was found for bilateral anterior insula, which persisted through the training. Following successful self-regulation, patients recognized disgust faces more accurately and happy faces less accurately. Improvements in disgust recognition were correlated with levels of self-activation of right insula. RtfMRI training led to an increase in the number of the incoming and outgoing effective connections of the anterior insula. This study shows for the first time that patients with schizophrenia can learn volitional brain regulation by rtfMRI feedback training leading to changes in the perception of emotions and modulations of the brain network connectivity. These findings open the door for further studies of rtfMRI in severely ill psychiatric populations, and possible therapeutic applications.

Dysbindin-1 genotype effects on emotional working memory

We combined functional imaging and genetics to investigate the behavioral and neural effects of a dysbindin-1 (DTNBP1) genotype associated with the expression level of this important synaptic protein, which has been implicated in schizophrenia. On a working memory (WM) task for emotional faces, participants with the genotype related to increased expression showed higher WM capacity for happy faces compared with the genotype related to lower expression. Activity in several task-related brain areas with known DTNBP1 expression was increased, including hippocampal, temporal and frontal cortex. Although these increases occurred across emotions, they were mostly observed in areas whose activity correlated with performance for happy faces. This suggests effects of variability in DTNBP1 on emotion-specific WM capacity and region-specific task-related brain activation in humans. Synaptic effects of DTNBP1 implicate that altered dopaminergic and/or glutamatergic neurotransmission may be related to the increased WM capacity. The combination of imaging and genetics thus allows us to bridge the gap between the cellular/molecular and systems/behavioral level and extend the cognitive neuroscience approach to a comprehensive biology of cognition.

Neuroimaging support for discrete neural correlates of basic emotions: a voxel-based meta-analysis

What is the basic structure of emotional experience and how is it represented in the human brain? One highly influential theory, discrete basic emotions, proposes a limited set of basic emotions such as happiness and fear, which are characterized by unique physiological and neural profiles. Although many studies using diverse methods have linked particular brain structures with specific basic emotions, evidence from individual neuroimaging studies and from neuroimaging meta-analyses has been inconclusive regarding whether basic emotions are associated with both consistent and discriminable regional brain activations. We revisited this question, using activation likelihood estimation (ALE), which allows spatially sensitive, voxelwise statistical comparison of results from multiple studies. In addition, we examined substantially more studies than previous meta-analyses. The ALE meta-analysis yielded results consistent with basic emotion theory. Each of the emotions examined (fear, anger, disgust, sadness, and happiness) was characterized by consistent neural correlates across studies, as defined by reliable correlations with regional brain activations. In addition, the activation patterns associated with each emotion were discrete (discriminable from the other emotions in pairwise contrasts) and overlapped substantially with structure-function correspondences identified using other approaches, providing converging evidence that discrete basic emotions have consistent and discriminable neural correlates. Complementing prior studies that have demonstrated neural correlates for the affective dimensions of arousal and valence, the current meta-analysis results indicate that the key elements of basic emotion views are reflected in neural correlates identified by neuroimaging studies.

Leaving a bad taste in your mouth but not in my insula

Previous research has implicated regions of anterior insula/frontal operculum in processing conspecific facial expressions of disgust. It has been suggested however that there are a variety of disgust facial expression components which relate to the disgust-eliciting stimulus. The nose wrinkle is predominantly associated with irritating or offensive smells, the mouth gape and tongue extrusion with distaste and oral irritation, while a broader range of disgust elicitors including aversive interpersonal contacts and certain moral offenses are associated primarily with the upper lip curl. Using functional magnetic resonance imaging, we show that activity in the anterior insula/frontal operculum is seen only in response to canonical disgust faces, exhibiting the nose wrinkle and upper lip curl, and not in response to distaste facial expressions, exhibiting a mouth gape and tongue protrusion. Canonical disgust expressions also result in activity in brain regions linked to social cognition more broadly, including dorsal medial prefrontal cortex, posterior cingulate cortex, temporo-parietal junction and superior temporal sulcus. We interpret these differences in relation to the relative functional and communicative roles of the different disgust expressions and suggest a significant role for appraisal processes in the insula activation to facial expressions of disgust.

Infection, incest, and iniquity: investigating the neural correlates of disgust and morality

Disgust, an emotion related to avoiding harmful substances, has been linked to moral judgments in many behavioral studies. However, the fact that participants report feelings of disgust when thinking about feces and a heinous crime does not necessarily indicate that the same mechanisms mediate these reactions. Humans might instead have separate neural and physiological systems guiding aversive behaviors and judgments across different domains. The present interdisciplinary study used functional magnetic resonance imaging (n = 50) and behavioral assessment to investigate the biological homology of pathogen-related and moral disgust. We provide evidence that pathogen-related and sociomoral acts entrain many common as well as unique brain networks. We also investigated whether morality itself is composed of distinct neural and behavioral subdomains. We provide evidence that, despite their tendency to elicit similar ratings of moral wrongness, incestuous and nonsexual immoral acts entrain dramatically separate, while still overlapping, brain networks. These results (i) provide support for the view that the biological response of disgust is intimately tied to immorality, (ii) demonstrate that there are at least three separate domains of disgust, and (iii) suggest strongly that morality, like disgust, is not a unified psychological or neurological phenomenon.

Sex differences in neural activation to facial expressions denoting contempt and disgust

The facial expression of contempt has been regarded to communicate feelings of moral superiority. Contempt is an emotion that is closely related to disgust, but in contrast to disgust, contempt is inherently interpersonal and hierarchical. The aim of this study was twofold. First, to investigate the hypothesis of preferential amygdala responses to contempt expressions versus disgust. Second, to investigate whether, at a neural level, men would respond stronger to biological signals of interpersonal superiority (e.g., contempt) than women. We performed an experiment using functional magnetic resonance imaging (fMRI), in which participants watched facial expressions of contempt and disgust in addition to neutral expressions. The faces were presented as distractors in an oddball task in which participants had to react to one target face. Facial expressions of contempt and disgust activated a network of brain regions, including prefrontal areas (superior, middle and medial prefrontal gyrus), anterior cingulate, insula, amygdala, parietal cortex, fusiform gyrus, occipital cortex, putamen and thalamus. Contemptuous faces did not elicit stronger amygdala activation than did disgusted expressions. To limit the number of statistical comparisons, we confined our analyses of sex differences to the frontal and temporal lobes. Men displayed stronger brain activation than women to facial expressions of contempt in the medial frontal gyrus, inferior frontal gyrus, and superior temporal gyrus. Conversely, women showed stronger neural responses than men to facial expressions of disgust. In addition, the effect of stimulus sex differed for men versus women. Specifically, women showed stronger responses to male contemptuous faces (as compared to female expressions), in the insula and middle frontal gyrus. Contempt has been conceptualized as signaling perceived moral violations of social hierarchy, whereas disgust would signal violations of physical purity. Thus, our results suggest a neural basis for sex differences in moral sensitivity regarding hierarchy on the one hand and physical purity on the other.

Effective connectivity between amygdala and orbitofrontal cortex differentiates the perception of facial expressions

Emotion research is guided both by the view that emotions are points in a dimensional space, such as valence or approach-withdrawal, and by the view that emotions are discrete categories. We determined whether effective connectivity of amygdala with medial orbitofrontal cortex (MOFC) and lateral orbitofrontal cortex (LOFC) differentiates the perception of emotion faces in a manner consistent with the dimensional and/or categorical view. Greater effective connectivity from left MOFC to amygdala differentiated positive and neutral expressions from negatively valenced angry, disgust, and fear expressions. Greater effective connectivity from right LOFC to amygdala differentiated emotion expressions conducive to perceiver approach (happy, neutral, and fear) from angry expressions that elicit perceiver withdrawal. Finally, consistent with the categorical view, there were unique patterns of connectivity in response to fear, anger, and disgust, although not in response to happy expressions, which did not differ from neutral ones.

Neural correlates of hate

In this work, we address an important but unexplored topic, namely the neural correlates of hate. In a block-design fMRI study, we scanned 17 normal human subjects while they viewed the face of a person they hated and also faces of acquaintances for whom they had neutral feelings. A hate score was obtained for the object of hate for each subject and this was used as a covariate in a between-subject random effects analysis. Viewing a hated face resulted in increased activity in the medial frontal gyrus, right putamen, bilaterally in premotor cortex, in the frontal pole and bilaterally in the medial insula. We also found three areas where activation correlated linearly with the declared level of hatred, the right insula, right premotor cortex and the right fronto-medial gyrus. One area of deactivation was found in the right superior frontal gyrus. The study thus shows that there is a unique pattern of activity in the brain in the context of hate. Though distinct from the pattern of activity that correlates with romantic love, this pattern nevertheless shares two areas with the latter, namely the putamen and the insula.

The human amygdala is involved in general behavioral relevance detection: evidence from an event-related functional magnetic resonance imaging Go-NoGo task

The amygdala is classically regarded as a detector of potential threat and as a critical component of the neural circuitry mediating conditioned fear responses. However, it has been reported that the human amygdala responds to multiple expressions of emotions as well as emotionally neutral stimuli of a novel, uncertain or ambiguous nature. Thus, it has been proposed that the function of the amygdala may be of a more general art, i.e. as a detector of behaviorally relevant stimuli [Sander D, Grafman J, Zalla T (2003) The human amygdala: an evolved system for relevance detection. Rev Neurosci 14:303-316]. To investigate this putative function of the amygdala, we used event related functional magnetic resonance imaging (fMRI) and a modified Go-NoGo task composed of behaviorally relevant and irrelevant letter and number stimuli. Analyses revealed bilateral amygdala activation in response to letter stimuli that were behaviorally relevant as compared with letters with less behavioral relevance. Similar results were obtained for relatively infrequent NoGo relevant stimuli as compared with more frequent Go stimuli. Our findings support a role for the human amygdala in general detection of behaviorally relevant stimuli.

Evaluating face trustworthiness: a model based approach

Judgments of trustworthiness from faces determine basic approach/avoidance responses and approximate the valence evaluation of faces that runs across multiple person judgments. Here, based on trustworthiness judgments and using a computer model for face representation, we built a model for representing face trustworthiness (study 1). Using this model, we generated novel faces with an increased range of trustworthiness and used these faces as stimuli in a functional Magnetic Resonance Imaging study (study 2). Although participants did not engage in explicit evaluation of the faces, the amygdala response changed as a function of face trustworthiness. An area in the right amygdala showed a negative linear response-as the untrustworthiness of faces increased so did the amygdala response. Areas in the left and right putamen, the latter area extended into the anterior insula, showed a similar negative linear response. The response in the left amygdala was quadratic--strongest for faces on both extremes of the trustworthiness dimension. The medial prefrontal cortex and precuneus also showed a quadratic response, but their response was strongest to faces in the middle range of the trustworthiness dimension.

Neural activities for negative priming with affective stimuli: an fMRI study

Negative priming refers to the slowing down in reaction time to a stimulus that is either the same as, or related to, a distracting stimulus that has been ignored by people in an immediately preceding trial. It can be used as an index to examine the extent to which people are able to disengage attention or even ignore a distracting stimulus. In this fMRI study, with healthy Mandarin-speaking Chinese participants, we replicated the basic negative priming effect with affectively neutral words. Negative priming was associated with increased activities in the anterior cingulate cortex and the insula, a result that supports the inhibition account of negative priming. We observed that the negative priming effect was attenuated by negative affective words, relative to neutral words, suggesting that subjects' inhibition of negative information was compromised. Such attenuation of negative priming by negative affective words was associated with increased activities in the ventrolateral and medial frontal regions, the hippocampus, and supplementary motor areas. These observations indicate that specific frontal and subcortical regions take part in attention orientation toward negative-affect information.