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

A Bayesian model of category-specific emotional brain responses

Understanding emotion is critical for a science of healthy and disordered brain function, but the neurophysiological basis of emotional experience is still poorly understood. We analyzed human brain activity patterns from 148 studies of emotion categories (2159 total participants) using a novel hierarchical Bayesian model. The model allowed us to classify which of five categories--fear, anger, disgust, sadness, or happiness--is engaged by a study with 66% accuracy (43-86% across categories). Analyses of the activity patterns encoded in the model revealed that each emotion category is associated with unique, prototypical patterns of activity across multiple brain systems including the cortex, thalamus, amygdala, and other structures. The results indicate that emotion categories are not contained within any one region or system, but are represented as configurations across multiple brain networks. The model provides a precise summary of the prototypical patterns for each emotion category, and demonstrates that a sufficient characterization of emotion categories relies on (a) differential patterns of involvement in neocortical systems that differ between humans and other species, and (b) distinctive patterns of cortical-subcortical interactions. Thus, these findings are incompatible with several contemporary theories of emotion, including those that emphasize emotion-dedicated brain systems and those that propose emotion is localized primarily in subcortical activity. They are consistent with componential and constructionist views, which propose that emotions are differentiated by a combination of perceptual, mnemonic, prospective, and motivational elements. Such brain-based models of emotion provide a foundation for new translational and clinical approaches.

Psicologia das emoções: uma proposta integrativa para compreender a expressão emocional

O presente trabalho realizou uma revisão da literatura das principais teorias sobre o funcionamento emocional: jamesianas, psicoevolucionistas, cognitivas e sociais. Com objetivo de integrar as propostas, foi desenvolvido um modelo constituído por aspectos cognitivos na avaliação do evento eliciador que conduzem a possíveis reações (impressão subjetiva, comportamento expresso e/ou alterações fisiológicas) e retroalimentam a interpretação. Esse modelo foi usado como base para apresentar características de expressão das emoções, sendo que seis emoções básicas foram discutidas (alegria, medo, surpresa, tristeza, nojo e raiva) com foco em seus aspectos expressivos faciais e cognitivos. Foi possível concluir que uma abordagem integrativa do fenômeno emocional pode trazer informações importantes para o trabalho do psicólogo.

High-frequency electroencephalographic activity in left temporal area is associated with pleasant emotion induced by video clips

Recent findings suggest that specific neural correlates for the key elements of basic emotions do exist and can be identified by neuroimaging techniques. In this paper, electroencephalogram (EEG) is used to explore the markers for video-induced emotions. The problem is approached from a classifier perspective: the features that perform best in classifying person's valence and arousal while watching video clips with audiovisual emotional content are searched from a large feature set constructed from the EEG spectral powers of single channels as well as power differences between specific channel pairs. The feature selection is carried out using a sequential forward floating search method and is done separately for the classification of valence and arousal, both derived from the emotional keyword that the subject had chosen after seeing the clips. The proposed classifier-based approach reveals a clear association between the increased high-frequency (15–32 Hz) activity in the left temporal area and the clips described as “pleasant” in the valence and “medium arousal” in the arousal scale. These clips represent the emotional keywords amusement and joy/happiness. The finding suggests the occurrence of a specific neural activation during video-induced pleasant emotion and the possibility to detect this from the left temporal area using EEG.

Multivariate neural biomarkers of emotional states are categorically distinct

Understanding how emotions are represented neurally is a central aim of affective neuroscience. Despite decades of neuroimaging efforts addressing this question, it remains unclear whether emotions are represented as distinct entities, as predicted by categorical theories, or are constructed from a smaller set of underlying factors, as predicted by dimensional accounts. Here, we capitalize on multivariate statistical approaches and computational modeling to directly evaluate these theoretical perspectives. We elicited discrete emotional states using music and films during functional magnetic resonance imaging scanning. Distinct patterns of neural activation predicted the emotion category of stimuli and tracked subjective experience. Bayesian model comparison revealed that combining dimensional and categorical models of emotion best characterized the information content of activation patterns. Surprisingly, categorical and dimensional aspects of emotion experience captured unique and opposing sources of neural information. These results indicate that diverse emotional states are poorly differentiated by simple models of valence and arousal, and that activity within separable neural systems can be mapped to unique emotion categories.

Rivalry of homeostatic and sensory-evoked emotions: Dehydration attenuates olfactory disgust and its neural correlates

Neural correlates have been described for emotions evoked by states of homeostatic imbalance (e.g. thirst, hunger, and breathlessness) and for emotions induced by external sensory stimulation (such as fear and disgust). However, the neurobiological mechanisms of their interaction, when they are experienced simultaneously, are still unknown. We investigated the interaction on the neurobiological and the perceptional level using subjective ratings, serum parameters, and functional magnetic resonance imaging (fMRI) in a situation of emotional rivalry, when both a homeostatic and a sensory-evoked emotion were experienced at the same time. Twenty highly dehydrated male subjects rated a disgusting odor as significantly less repulsive when they were thirsty. On the neurobiological level, we found that this reduction in subjective disgust during thirst was accompanied by a significantly reduced neural activity in the insular cortex, a brain area known to be considerably involved in processing of disgust. Furthermore, during the experience of disgust in the satiated condition, we observed a significant functional connectivity between brain areas responding to the disgusting odor, which was absent during the stimulation in the thirsty condition. These results suggest interference of conflicting emotions: an acute homeostatic imbalance can attenuate the experience of another emotion evoked by the sensory perception of a potentially harmful external agent. This finding offers novel insights with regard to the behavioral relevance of biologically different types of emotions, indicating that some types of emotions are more imperative for behavior than others. As a general principle, this modulatory effect during the conflict of homeostatic and sensory-evoked emotions may function to safeguard survival.

Feel between the lines: implied emotion in sentence comprehension

This study investigated the brain regions for the comprehension of implied emotion in sentences. Participants read negative sentences without negative words, for example, "The boy fell asleep and never woke up again," and their neutral counterparts "The boy stood up and grabbed his bag." This kind of negative sentence allows us to examine implied emotion derived at the sentence level, without associative emotion coming from word retrieval. We found that implied emotion in sentences, relative to neutral sentences, led to activation in some emotion-related areas, including the medial prefrontal cortex, the amygdala, and the insula, as well as certain language-related areas, including the inferior frontal gyrus, which has been implicated in combinatorial processing. These results suggest that the emotional network involved in implied emotion is intricately related to the network for combinatorial processing in language, supporting the view that sentence meaning is more than simply concatenating the meanings of its lexical building blocks.

Intrinsic connectivity in the human brain does not reveal networks for 'basic' emotions

We tested two competing models for the brain basis of emotion, the basic emotion theory and the conceptual act theory of emotion, using resting-state functional connectivity magnetic resonance imaging (rs-fcMRI). The basic emotion view hypothesizes that anger, sadness, fear, disgust and happiness each arise from a brain network that is innate, anatomically constrained and homologous in other animals. The conceptual act theory of emotion hypothesizes that an instance of emotion is a brain state constructed from the interaction of domain-general, core systems within the brain such as the salience, default mode and frontoparietal control networks. Using peak coordinates derived from a meta-analysis of task-evoked emotion fMRI studies, we generated a set of whole-brain rs-fcMRI 'discovery' maps for each emotion category and examined the spatial overlap in their conjunctions. Instead of discovering a specific network for each emotion category, variance in the discovery maps was accounted for by the known domain-general network. Furthermore, the salience network is observed as part of every emotion category. These results indicate that specific networks for each emotion do not exist within the intrinsic architecture of the human brain and instead support the conceptual act theory of emotion.

Associations between early adrenarche, affective brain function and mental health in children

Early timing of adrenarche, associated with relatively high levels of Dehydroepiandrosterone (DHEA) in children, has been associated with mental health and behavioral problems. However, little is known about effects of adreneracheal timing on brain function. The aim of this study was to investigate the effects of early adrenarche (defined by high DHEA levels independent of age) on affective brain function and symptoms of psychopathology in late childhood (N = 83, 43 females, M age 9.53 years, s.d. 0.34 years). Results showed that higher DHEA levels were associated with decreased affect-related brain activity (i) in the mid-cingulate cortex in the whole sample, and (ii) in a number of cortical and subcortical regions in female but not male children. Higher DHEA levels were also associated with increased externalizing symptoms in females, an association that was partly mediated by posterior insula activation to happy facial expressions. These results suggest that timing of adrenarche is an important moderator of affect-related brain function, and that this may be one mechanism linking early adrenarche to psychopathology.

The Brain Basis of Positive and Negative Affect: Evidence from a Meta-Analysis of the Human Neuroimaging Literature

The ability to experience pleasant or unpleasant feelings or to represent objects as "positive" or "negative" is known as representing hedonic "valence." Although scientists overwhelmingly agree that valence is a basic psychological phenomenon, debate continues about how to best conceptualize it scientifically. We used a meta-analysis of 397 functional magnetic resonance imaging (fMRI) and positron emission tomography studies (containing 914 experimental contrasts and 6827 participants) to test 3 competing hypotheses about the brain basis of valence: the bipolarity hypothesis that positive and negative affect are supported by a brain system that monotonically increases and/or decreases along the valence dimension, the bivalent hypothesis that positive and negative affect are supported by independent brain systems, and the affective workspace hypothesis that positive and negative affect are supported by a flexible set of valence-general regions. We found little evidence for the bipolar or bivalent hypotheses. Findings instead supported the hypothesis that, at the level of brain activity measurable by fMRI, valence is flexibly implemented across instances by a set of valence-general limbic and paralimbic brain regions.

A Constructionist Review of Morality and Emotions

Morality and emotions are linked, but what is the nature of their correspondence? Many “whole number” accounts posit specific correspondences between moral content and discrete emotions, such that harm is linked to anger, and purity is linked to disgust. A review of the literature provides little support for these specific morality–emotion links. Moreover, any apparent specificity may arise from global features shared between morality and emotion, such as affect and conceptual content. These findings are consistent with a constructionist perspective of the mind, which argues against a whole number of discrete and domain-specific mental mechanisms underlying morality and emotion. Instead, constructionism emphasizes the flexible combination of basic and domain-general ingredients such as core affect and conceptualization in creating the experience of moral judgments and discrete emotions. The implications of constructionism in moral psychology are discussed, and we propose an experimental framework for rigorously testing morality–emotion links.

Extracting neurophysiological signals reflecting users' emotional and affective responses to BCI use: A systematic literature review

BACKGROUND

Brain-computer interfaces (BCIs) allow persons with impaired mobility to communicate and interact with the environment, supporting goal-directed thinking and cognitive function. Ideally, a BCI should be able to recognize a user's internal state and adapt to it in real-time, to improve interaction.

OBJECTIVE

Our aim was to examine studies investigating the recognition of affective states from neurophysiological signals, evaluating how current achievements can be applied to improve BCIs.

METHODS

Following the PRISMA guidelines, we performed a literature search using PubMed and ProQuest databases. We considered peer-reviewed research articles in English, focusing on the recognition of emotions from neurophysiological signals in view of enhancing BCI use.

RESULTS

Of the 526 identified records, 30 articles comprising 32 studies were eligible for review. Their analysis shows that the affective BCI field is developing, with a variety of combinations of neuroimaging techniques, selected neurophysiological features, and classification algorithms currently being tested. Nevertheless, there is a gap between laboratory experiments and their translation to everyday situations.

CONCLUSIONS

BCI developers should focus on testing emotion classification with patients in ecological settings and in real-time, with more precise definitions of what they are investigating, and communicating results in a standardized way.

Circuit to construct mapping: a mathematical tool for assisting the diagnosis and treatment in major depressive disorder

Major depressive disorder (MDD) is a serious condition with a lifetime prevalence exceeding 16% worldwide. MDD is a heterogeneous disorder that involves multiple behavioral symptoms on the one hand and multiple neuronal circuits on the other hand. In this review, we integrate the literature on cognitive and physiological biomarkers of MDD with the insights derived from mathematical models of brain networks, especially models that can be used for fMRI datasets. We refer to the recent NIH research domain criteria initiative, in which a concept of "constructs" as functional units of mental disorders is introduced. Constructs are biomarkers present at multiple levels of brain functioning - cognition, genetics, brain anatomy, and neurophysiology. In this review, we propose a new approach which we called circuit to construct mapping (CCM), which aims to characterize causal relations between the underlying network dynamics (as the cause) and the constructs referring to the clinical symptoms of MDD (as the effect). CCM involves extracting diagnostic categories from behavioral data, linking circuits that are causal to these categories with use of clinical neuroimaging data, and modeling the dynamics of the emerging circuits with attractor dynamics in order to provide new, neuroimaging-related biomarkers for MDD. The CCM approach optimizes the clinical diagnosis and patient stratification. It also addresses the recent demand for linking circuits to behavior, and provides a new insight into clinical treatment by investigating the dynamics of neuronal circuits underneath cognitive dimensions of MDD. CCM can serve as a new regime toward personalized medicine, assisting the diagnosis and treatment of MDD.

Cognitive content specificity in anxiety and depressive disorder symptoms: a twin study of cross-sectional associations with anxiety sensitivity dimensions across development

BACKGROUND

The classification of anxiety and depressive disorders has long been debated and has important clinical implications. The present study combined a genetically sensitive design and multiple time points to investigate cognitive content specificity in anxiety and depressive disorder symptoms across anxiety sensitivity dimensions, a cognitive distortion implicated in both disorders.

METHOD

Phenotypic and genetic correlations between anxiety sensitivity dimensions, anxiety and depressive disorder symptoms were examined at five waves of data collection within childhood, adolescence and early adulthood in two representative twin studies (n pairs = 300 and 1372).

RESULTS

The physical concerns dimension of anxiety sensitivity (fear of bodily symptoms) was significantly associated with anxiety but not depression at all waves. Genetic influences on physical concerns overlapped substantially more with anxiety than depression. Conversely, mental concerns (worry regarding cognitive control) were phenotypically more strongly associated with depression than anxiety. Social concerns (fear of publicly observable symptoms of anxiety) were associated with both anxiety and depression in adolescence. Genetic influences on mental and social concerns were shared to a similar extent with both anxiety and depression.

CONCLUSIONS

Phenotypic patterns of cognitive specificity and broader genetic associations between anxiety sensitivity dimensions, anxiety and depressive disorder symptoms were similar at all waves. Both disorder-specific and shared cognitive concerns were identified, suggesting it is appropriate to classify anxiety and depression as distinct but related disorders and confirming the clinical perspective that cognitive therapy is most likely to benefit by targeting cognitive concerns relating specifically to the individual's presenting symptoms across development.

Insomnia disorder is associated with increased amygdala reactivity to insomnia-related stimuli

STUDY OBJECTIVES

Alterations in emotional reactivity may play a key role in the pathophysiology of insomnia disorder (ID). However, only few supporting experimental data are currently available. We evaluated in a hypothesis-driven design whether patients with ID present altered amygdale responses to emotional stimuli related and unrelated to the experience of insomnia and, because of chronic hyperarousal, less habituation of amygdala responses.

DESIGN

Case-control study.

SETTING

Departments of Psychiatry and Psychotherapy and of Radiology of the University of Freiburg Medical Center.

PARTICIPANTS

There were 22 patients with ID (15 females; 7 males; age 40.7 ± 12.6 y) and 38 healthy good sleepers (HGS, 21 females; 17 males; age 39.6 ± 8.9 y).

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

In a functional magnetic resonance imaging session, five different blocks of pictures with varying emotional arousal, valence, and content (insomnia-relatedness) were presented. Pictures were presented twice to test for habituation processes. Results showed that patients with ID, compared to HGS, presented heightened amygdala responses to insomnia-related stimuli. Moreover, habituation of amygdale responses was observed only in HGS, but not in patients with ID who showed a mixed pattern of amygdala responses to the second presentation of the stimuli.

CONCLUSIONS

The results provide evidence for an insomnia-related emotional bias in patients with ID. Cognitive behavior treatment for ID could benefit from strategies dealing with the emotional charge associated with the disorder. Further studies should clarify the role of ID with respect to habituation of amygdala responses.

Exploring emotions using invasive methods: review of 60 years of human intracranial electrophysiology

Over the past 60 years, human intracranial electrophysiology (HIE) has been used to characterize seizures in patients with epilepsy. Secondary to the clinical objectives, electrodes implanted intracranially have been used to investigate mechanisms of human cognition. In addition to studies of memory and language, HIE methods have been used to investigate emotions. The aim of this review is to outline the contribution of HIE (electrocorticography, single-unit recording and electrical brain stimulation) to our understanding of the neural representations of emotions. We identified 64 papers dating back to the mid-1950s which used HIE techniques to study emotional states. Evidence from HIE studies supports the existence of widely distributed networks in the neocortex, limbic/paralimbic regions and subcortical nuclei which contribute to the representation of emotional states. In addition, evidence from HIE supports hemispheric dominance for emotional valence. Furthermore, evidence from HIE supports the existence of overlapping neural areas for emotion perception, experience and expression. Lastly, HIE provides unique insights into the temporal dynamics of neural activation during perception, experience and expression of emotional states. In conclusion, we propose that HIE techniques offer important evidence which must be incorporated into our current models of emotion representation in the human brain.

Towards a constructionist approach to emotions: verification of the three-dimensional model of affect with EEG-independent component analysis

The locationist model of affect, which assumes separate brain structures devoted to particular discrete emotions, is currently being questioned as it has not received enough convincing experimental support. An alternative, constructionist approach suggests that our emotional states emerge from the interaction between brain functional networks, which are related to more general, continuous affective categories. In the study, we tested whether the three-dimensional model of affect based on valence, arousal, and dominance (VAD) can reflect brain activity in a more coherent way than the traditional locationist approach. Independent components of brain activity were derived from spontaneous EEG recordings and localized using the DIPFIT method. The correspondence between the spectral power of the revealed brain sources and a mood self-report quantified on the VAD space was analysed. Activation of four (out of nine) clusters of independent brain sources could be successfully explained by the specific combination of three VAD dimensions. The results support the constructionist theory of emotions.

Discrete Emotions and Developmental Psychopathology: The Alchemical Legacy of Carroll Izard

Carroll Izard completed his dissertation in 1952, beginning a career spanning more than six decades that coincided with clinical psychology maturing as a profession, and the birth of clinical science and cognitive neuroscience. Izard’s focus on discrete emotions as evolved systems that organize information, prepare responses, and shape the development of personality and relationships persisted through his career, despite “emotions” often being overshadowed by psychodynamic, behavioral, or cognitive perspectives. His theoretical work anticipated and now integrates contemporary neuroscience and relational perspectives. Exploration of discrete emotions has kept lines of inquiry open that enrich our understanding of psychopathology. Izard also embraced clinical science, combining basic research with effectiveness studies addressing the unmet need for mental health services via emotion-focused interventions.

Neural responses to facial expressions support the role of the amygdala in processing threat

The amygdala is known to play an important role in the response to facial expressions that convey fear. However, it remains unclear whether the amygdala's response to fear reflects its role in the interpretation of danger and threat, or whether it is to some extent activated by all facial expressions of emotion. Previous attempts to address this issue using neuroimaging have been confounded by differences in the use of control stimuli across studies. Here, we address this issue using a block design functional magnetic resonance imaging paradigm, in which we compared the response to face images posing expressions of fear, anger, happiness, disgust and sadness with a range of control conditions. The responses in the amygdala to different facial expressions were compared with the responses to a non-face condition (buildings), to mildly happy faces and to neutral faces. Results showed that only fear and anger elicited significantly greater responses compared with the control conditions involving faces. Overall, these findings are consistent with the role of the amygdala in processing threat, rather than in the processing of all facial expressions of emotion, and demonstrate the critical importance of the choice of comparison condition to the pattern of results.

Identifying the core components of emotional intelligence: evidence from amplitude of low-frequency fluctuations during resting state

Emotional intelligence (EI) is a multi-faceted construct consisting of our ability to perceive, monitor, regulate and use emotions. Despite much attention being paid to the neural substrates of EI, little is known of the spontaneous brain activity associated with EI during resting state. We used resting-state fMRI to investigate the association between the amplitude of low-frequency fluctuations (ALFFs) and EI in a large sample of young, healthy adults. We found that EI was significantly associated with ALFFs in key nodes of two networks: the social emotional processing network (the fusiform gyrus, right superior orbital frontal gyrus, left inferior frontal gyrus and left inferior parietal lobule) and the cognitive control network (the bilateral pre-SMA, cerebellum and right precuneus). These findings suggest that the neural correlates of EI involve several brain regions in two crucial networks, which reflect the core components of EI: emotion perception and emotional control.

Resting-state functional connectivity in anterior cingulate cortex in normal aging

Growing evidence suggests that normal aging is associated with cognitive decline and well-maintained emotional well-being. The anterior cingulate cortex (ACC) is an important brain region involved in emotional and cognitive processing. We investigated resting-state functional connectivity (FC) of two ACC subregions in 30 healthy older adults vs. 33 healthy younger adults, by parcellating into rostral (rACC) and dorsal (dACC) ACC based on clustering of FC profiles. Compared with younger adults, older adults demonstrated greater connection between rACC and anterior insula, suggesting that older adults recruit more proximal dACC brain regions connected with insula to maintain a salient response. Older adults also demonstrated increased FC between rACC and superior temporal gyrus and inferior frontal gyrus, decreased integration between rACC and default mode, and decreased dACC-hippocampal and dACC-thalamic connectivity. These altered FCs reflected rACC and dACC reorganization, and might be related to well emotion regulation and cognitive decline in older adults. Our findings provide further insight into potential functional substrates of emotional and cognitive alterations in the aging brain.

A Functionalist Manifesto: Goal-Related Emotions From an Evolutionary Perspective

Functional theories posit that emotions are elicited by particular goal-related situations that represented adaptive problems and that emotions are evolved features of coordinated responses to those situations. Yet little theory or research has addressed the evolutionary aspects of these theories. We apply five criteria that can be used to judge whether features are adaptations. There is evidence that sadness, anger, and anxiety relate to unique changes in physiology, cognition, and behavior, those changes are correlated, situations that give rise to emotions are consistent, and emotions are complex. To date, there is little experimental evidence regarding whether discrete emotions resolve adaptive problems and do so relatively efficiently. Evidence supporting all criteria is required to claim that discrete emotions are evolved features.

Spatial frequency filtered images reveal differences between masked and unmasked processing of emotional information

High and low spatial frequency information has been shown to contribute differently to the processing of emotional information. In three priming studies using spatial frequency filtered emotional face primes, emotional face targets, and an emotion categorization task, we investigated this issue further. Differences in the pattern of results between short and masked, and short and long unmasked presentation conditions emerged. Given long and unmasked prime presentation, high and low frequency primes triggered emotion-specific priming effects. Given brief and masked prime presentation in Experiment 2, we found a dissociation: High frequency primes caused a valence priming effect, whereas low frequency primes yielded a differentiation between low and high arousing information within the negative domain. Brief and unmasked prime presentation in Experiment 3 revealed that subliminal processing of primes was responsible for the pattern observed in Experiment 2. The implications of these findings for theories of early emotional information processing are discussed.

Mood-dependent integration in discourse comprehension: happy and sad moods affect consistency processing via different brain networks

According to recent research on language comprehension, the semantic features of a text are not the only determinants of whether incoming information is understood as consistent. Listeners' pre-existing affective states play a crucial role as well. The current fMRI experiment examines the effects of happy and sad moods during comprehension of consistent and inconsistent story endings, focusing on brain regions previously linked to two integration processes: inconsistency detection, evident in stronger responses to inconsistent endings, and fluent processing (accumulation), evident in stronger responses to consistent endings. The analysis evaluated whether differences in the BOLD response for consistent and inconsistent story endings correlated with self-reported mood scores after a mood induction procedure. Mood strongly affected regions previously associated with inconsistency detection. Happy mood increased sensitivity to inconsistency in regions specific for inconsistency detection (e.g., left IFG, left STS), whereas sad mood increased sensitivity to inconsistency in regions less specific for language processing (e.g., right med FG, right SFG). Mood affected more weakly regions involved in accumulation of information. These results show that mood can influence activity in areas mediating well-defined language processes, and highlight that integration is the result of context-dependent mechanisms. The finding that language comprehension can involve different networks depending on people's mood highlights the brain's ability to reorganize its functions.

Feature-based representations of emotional facial expressions in the human amygdala

The amygdala plays a central role in processing facial affect, responding to diverse expressions and features shared between expressions. Although speculation exists regarding the nature of relationships between expression- and feature-specific amygdala reactivity, this matter has not been fully explored. We used functional magnetic resonance imaging and principal component analysis (PCA) in a sample of 300 young adults, to investigate patterns related to expression- and feature-specific amygdala reactivity to faces displaying neutral, fearful, angry or surprised expressions. The PCA revealed a two-dimensional correlation structure that distinguished emotional categories. The first principal component separated neutral and surprised from fearful and angry expressions, whereas the second principal component separated neutral and angry from fearful and surprised expressions. This two-dimensional correlation structure of amygdala reactivity may represent specific feature-based cues conserved across discrete expressions. To delineate which feature-based cues characterized this pattern, face stimuli were averaged and then subtracted according to their principal component loadings. The first principal component corresponded to displacement of the eyebrows, whereas the second principal component corresponded to increased exposure of eye whites together with movement of the brow. Our results suggest a convergent representation of facial affect in the amygdala reflecting feature-based processing of discrete expressions.

Effects of reward contingencies on brain activation during feedback processing

This study investigates differential neural activation patterns in response to reward-related feedback depending on various reward contingencies. Three types of reward contingencies were compared: a “gain” contingency (a monetary reward for correct answer/no monetary penalty for incorrect answer); a “lose” contingency (no monetary reward for correct answer/a monetary penalty for incorrect answer); and a “combined” contingency (a monetary reward for correct answer/a monetary penalty for incorrect answer). Sixteen undergraduate students were exposed to the three reward contingencies while performing a series of perceptual judgment tasks. The fMRI results revealed that only the “gain” contingency recruited the ventral striatum, a region associated with positive affect and motivation, during overall feedback processing. Specifically, the ventral striatum was more activated under the “gain” contingency than under the other two contingencies when participants received positive feedback. In contrast, when participants received negative feedback, the ventral striatum was less deactivated under the “gain” and “lose” contingencies than under the “combined” contingency. Meanwhile, the negative feedback elicited significantly stronger activity in the dorsal amygdala, a region tracking the intensity and motivational salience of stimuli, under the “gain” and “lose” contingencies. These findings suggest the important role of contextual factor, such as reward contingency, in feedback processing. Based on the current findings, we recommend implementing the “gain” contingency to maintain individuals’ optimal motivation.

Anticipation of high arousal aversive and positive movie clips engages common and distinct neural substrates

The neural correlates of anxious anticipation have been primarily studied with aversive and neutral stimuli. In this study, we examined the effect of valence on anticipation by using high arousal aversive and positive stimuli and a condition of uncertainty (i.e. either positive or aversive). The task consisted of predetermined cues warning participants of upcoming aversive, positive, 'uncertain' (either aversive or positive) and neutral movie clips. Anticipation of all affective clips engaged common regions including the anterior insula, dorsal anterior cingulate cortex, thalamus, caudate, inferior parietal and prefrontal cortex that are associated with emotional experience, sustained attention and appraisal. In contrast, the nucleus accumbens and medial prefrontal cortex, regions implicated in reward processing, were selectively engaged during anticipation of positive clips (depicting sexually explicit content) and the mid-insula, which has been linked to processing aversive stimuli, was selectively engaged during anticipation of aversive clips (depicting graphic medical procedures); these three areas were also activated during anticipation of 'uncertain' clips reflecting a broad preparatory response for both aversive and positive stimuli. These results suggest that a common circuitry is recruited in anticipation of affective clips regardless of valence, with additional areas preferentially engaged depending on whether expected stimuli are negative or positive.

Utilizing heartbeat evoked potentials to identify cardiac regulation of vagal afferents during emotion and resonant breathing

The importance of the bi-directional communication between the heart and brain has been known for over 100 years (Lane et al. in NeuroImage 44:213-222, 2009a, Psychosom Med 2:117-134, 2009b) and plays an important role in many of the prominent theories of psychophysiology today. Utilizing heartbeat evoked potentials (HEPs), we sought to determine whether heart rate variability (HRV) was related to the strength of the connection between the heart and brain. We also hypothesized that differing emotion states would result in differing amplitudes of HEPs. Participants were induced into emotional states with an autobiographical script of their happiest and saddest memory. HEPs were also recorded during diaphragmatic breathing at six breaths per minute. The evoked potentials during the emotional conditions, especially negative emotion were most attenuated. We believe that the signal from the heart to the brain may be filtered by central limbic structures affecting the level of the signal at the cortex. It also appears that HRV affects the strength of HEPs, especially during resonant breathing. Significant neurocardiac gender differences were also present across all conditions. The results of this study support the theory and speculation of many authors who believe vagal afferents play a role in brain function.

Impairments in facial affect recognition associated with autism spectrum disorders: a meta-analysis

Autism spectrum disorders (ASDs) are characterized by social impairments, including inappropriate responses to affective stimuli and nonverbal cues, which may extend to poor face-emotion recognition. However, the results of empirical studies of face-emotion recognition in individuals with ASD have yielded inconsistent findings that occlude understanding the role of face-emotion recognition deficits in the development of ASD. The goal of this meta-analysis was to address three as-yet unanswered questions. Are ASDs associated with consistent face-emotion recognition deficits? Do deficits generalize across multiple emotional expressions or are they limited to specific emotions? Do age or cognitive intelligence affect the magnitude of identified deficits? The results indicate that ASDs are associated with face-emotion recognition deficits across multiple expressions and that the magnitude of these deficits increases with age and cannot be accounted for by intelligence. These findings suggest that, whereas neurodevelopmental processes and social experience produce improvements in general face-emotion recognition abilities over time during typical development, children with ASD may experience disruptions in these processes, which suggested distributed functional impairment in the neural architecture that subserves face-emotion processing, an effect with downstream developmental consequences.

Anatomical deficits in adult posttraumatic stress disorder: a meta-analysis of voxel-based morphometry studies

Evidence from previous anatomical studies indicate that widespread brain regions are involved in the pathogenesis of posttraumatic stress disorder (PTSD). The aim of the present study was to quantitatively integrate the literature on structural abnormalities seen on individuals with PTSD. Twenty voxel-based analysis studies were analysed through a comprehensive series of meta-analyses. Compared with healthy controls, PTSD patients showed a significant reduction in grey matter (GM) in the left anterior cingulate gyrus (ACC) at the whole-brain level. Several brain regions, including the left ACC, the left insula and the right parahippocampal gyrus were significantly smaller in individuals with PTSD than in trauma-exposed healthy subjects. Furthermore, the clinician-administered PTSD scale scores were negatively correlated with GM in the left ACC and positively correlated with GM in the left insula. In addition, PTSD patients who experienced accidental or non-accidental trauma had anatomical changes in different brain regions. These results suggest that the smaller ACC and insular cortex within the limbic-prefrontal circuit contribute to the pathogenesis of PTSD. Moreover, the PTSD patients with different types of trauma may have different cerebral deficits.

Amygdala mediated connectivity in perceptual decision-making of emotional facial expressions

Recognizing emotional facial expressions is a part of perceptual decision-making processes in the brain. Arriving at a decision for the brain becomes more difficult when available sensory information is limited or ambiguous. We used clear and noisy pictures with happy and angry emotional expressions and asked 32 participants to categorize these pictures based on emotions. There were significant differences in behavioral accuracy and reaction time between the decisions of clear and noisy images. The functional magnetic resonance imaging activations showed that the inferior occipital gyrus (IOG), fusiform gyrus (FG), amygdala (AMG) and ventrolateral prefrontal cortex (VPFC) along with other regions were active during the perceptual decision-making process. Using dynamic causal modeling analysis, we obtained three important results. First, from Bayesian model selection (BMS) approach, we found that the feed-forward network activity was enhanced during the processing of clear and noisy happy faces more than during the processing of clear angry faces. The AMG mediated this feed-forward connectivity in processing of clear and noisy happy faces, whereas the AMG mediation was absent in case of clear angry faces. However, this network activity was enhanced in case of noisy angry faces. Second, connectivity parameters obtained from Bayesian model averaging (BMA) suggested that the forward connectivity dominated over the backward connectivity during such processes. Third, based on the BMA parameters, we found that the easier tasks modulated effective connectivity from IOG to FG, AMG, and VPFC more than the difficult tasks did. These findings suggest that both parallel and hierarchical brain processes are at work during perceptual decision-making of negative, positive, unambiguous and ambiguous emotional expressions, but the AMG-mediated feed-forward network plays a dominant role in such decisions.

Music-evoked incidental happiness modulates probability weighting during risky lottery choices

We often make decisions with uncertain consequences. The outcomes of the choices we make are usually not perfectly predictable but probabilistic, and the probabilities can be known or unknown. Probability judgments, i.e., the assessment of unknown probabilities, can be influenced by evoked emotional states. This suggests that also the weighting of known probabilities in decision making under risk might be influenced by incidental emotions, i.e., emotions unrelated to the judgments and decisions at issue. Probability weighting describes the transformation of probabilities into subjective decision weights for outcomes and is one of the central components of cumulative prospect theory (CPT) that determine risk attitudes. We hypothesized that music-evoked emotions would modulate risk attitudes in the gain domain and in particular probability weighting. Our experiment featured a within-subject design consisting of four conditions in separate sessions. In each condition, the 41 participants listened to a different kind of music—happy, sad, or no music, or sequences of random tones—and performed a repeated pairwise lottery choice task. We found that participants chose the riskier lotteries significantly more often in the “happy” than in the “sad” and “random tones” conditions. Via structural regressions based on CPT, we found that the observed changes in participants' choices can be attributed to changes in the elevation parameter of the probability weighting function: in the “happy” condition, participants showed significantly higher decision weights associated with the larger payoffs than in the “sad” and “random tones” conditions. Moreover, elevation correlated positively with self-reported music-evoked happiness. Thus, our experimental results provide evidence in favor of a causal effect of incidental happiness on risk attitudes that can be explained by changes in probability weighting.

A case of bilateral frontal tumors without "frontal syndrome"

We report the longitudinal case study of a right-handed patient harboring two frontal tumors that benefited from bilateral simultaneous surgery. The tumors were WHO Grade II gliomas located in the left inferior frontal area (including the cingulate gyrus) and the right anterior superior frontal gyrus. The double tumor resection was guided by direct electrical stimulation of brain areas while the patient was awake. Neuropsychological assessments were administered before and after the surgery to analyse how the brain functions in the presence of two frontal gliomas that affect both hemispheres and reacts to a bilateral resection, which can brutally compromise the neuronal connectivity, progressively established during the infiltrating process. We showed that both the tumor infiltration and their bilateral resection did not lead to a "frontal syndrome" or a "dysexecutive syndrome" predicted by the localization models. However, a subtle fragility was observed in fine-grain language, memory and emotional skills. This case study reveals the significance of brain plasticity in the reorganization of cognitive networks, even in cases of bilateral tumors. It also confirms the clinical relevance of hodotopical brain models, which considers the brain to be organized in parallel-distributed networks around cortical centers and epicenters.

An ERP study of vocal emotion processing in asymmetric Parkinson's disease

Parkinson's disease (PD) has been related to impaired processing of emotional speech intonation (emotional prosody). One distinctive feature of idiopathic PD is motor symptom asymmetry, with striatal dysfunction being strongest in the hemisphere contralateral to the most affected body side. It is still unclear whether this asymmetry may affect vocal emotion perception. Here, we tested 22 PD patients (10 with predominantly left-sided [LPD] and 12 with predominantly right-sided motor symptoms) and 22 healthy controls in an event-related potential study. Sentences conveying different emotional intonations were presented in lexical and pseudo-speech versions. Task varied between an explicit and an implicit instruction. Of specific interest was emotional salience detection from prosody, reflected in the P200 component. We predicted that patients with predominantly right-striatal dysfunction (LPD) would exhibit P200 alterations. Our results support this assumption. LPD patients showed enhanced P200 amplitudes, and specific deficits were observed for disgust prosody, explicit anger processing and implicit processing of happy prosody. Lexical speech was predominantly affected while the processing of pseudo-speech was largely intact. P200 amplitude in patients correlated significantly with left motor scores and asymmetry indices. The data suggest that emotional salience detection from prosody is affected by asymmetric neuronal degeneration in PD.

Temporal and spatial neural dynamics in the perception of basic emotions from complex scenes

The different temporal dynamics of emotions are critical to understand their evolutionary role in the regulation of interactions with the surrounding environment. Here, we investigated the temporal dynamics underlying the perception of four basic emotions from complex scenes varying in valence and arousal (fear, disgust, happiness and sadness) with the millisecond time resolution of Electroencephalography (EEG). Event-related potentials were computed and each emotion showed a specific temporal profile, as revealed by distinct time segments of significant differences from the neutral scenes. Fear perception elicited significant activity at the earliest time segments, followed by disgust, happiness and sadness. Moreover, fear, disgust and happiness were characterized by two time segments of significant activity, whereas sadness showed only one long-latency time segment of activity. Multidimensional scaling was used to assess the correspondence between neural temporal dynamics and the subjective experience elicited by the four emotions in a subsequent behavioral task. We found a high coherence between these two classes of data, indicating that psychological categories defining emotions have a close correspondence at the brain level in terms of neural temporal dynamics. Finally, we localized the brain regions of time-dependent activity for each emotion and time segment with the low-resolution brain electromagnetic tomography. Fear and disgust showed widely distributed activations, predominantly in the right hemisphere. Happiness activated a number of areas mostly in the left hemisphere, whereas sadness showed a limited number of active areas at late latency. The present findings indicate that the neural signature of basic emotions can emerge as the byproduct of dynamic spatiotemporal brain networks as investigated with millisecond-range resolution, rather than in time-independent areas involved uniquely in the processing one specific emotion.

The evolutionary psychology of women's aggression

Evolutionary researchers have identified age, operational sex ratio and high variance in male resources as factors that intensify female competition. These are discussed in relation to escalated intrasexual competition for men and their resources between young women in deprived neighbourhoods. For these women, fighting is not seen as antithetical to cultural conceptions of femininity, and female weakness is disparaged. Nonetheless, even where competitive pressures are high, young women's aggression is less injurious and frequent than young men's. From an evolutionary perspective, I argue that the intensity of female aggression is constrained by the greater centrality of mothers, rather than fathers, to offspring survival. This selection pressure is realized psychologically through a lower threshold for fear among women. Neuropsychological evidence is not yet conclusive but suggests that women show heightened amygdala reactivity to threatening stimuli, may be better able to exert prefrontal cortical control over emotional behaviour and may consciously register fear more strongly via anterior cingulate activity. The impact of testosterone and oxytocin on the neural circuitry of emotion is also considered.

Comment: On the Role of Appraisal Processes in the Construction of Emotion

Appraisal and constructivist theories of emotion both emphasize that emotions are not modular phenomena, but are constructed from more basic psychological parts. In the scientific debate, differences between the two approaches are sometimes overplayed, by classifying appraisal theories as “natural kinds” models, and sometimes underplayed, by basically merging them into constructivist accounts. The aim of this contribution is to illustrate some similarities and some differences between contemporary appraisal and constructivist approaches, and to highlight the fact that appraisal theory has indeed already confronted the idea of construction in the elicitation of emotion. In doing so, I want to argue that, while there is a distinction between appraisal and constructivist camps, it is not as stark as one might think, even though the names of the “ingredients” of emotions may differ.