Flexibly adapting to emotional cues: Examining the functional and structural correlates of emotional reactivity and emotion control in healthy and depressed individuals

The ability of emotionally significant stimuli to bias our behaviour is an evolutionarily adaptive phenomenon. However, sometimes emotions become excessive, inappropriate, and even pathological, like in major depressive disorder (MDD). Emotional flexibility includes both the neural processes involved in reacting to, or representing, emotional significance, and those involved in controlling emotional reactivity. MDD represents a potentially distinct form of emotion (in)flexibility, and therefore offers a unique perspective for understanding both the integration of conflicting emotional cues and the neural regions involved in actively controlling emotional systems. The present investigation of emotional flexibility began by considering the functional neural correlates of competing socio-emotional cues and effortful emotion regulation in MDD using both negative and positive emotions. Study 1 revealed greater amygdala activity in MDD relative to control participants when negative cues were centrally presented and task-relevant. No significant between-group differences were observed in the amygdala for peripheral task-irrelevant negative distracters. However, controls demonstrated greater recruitment of the ventrolateral (vlPFC) and dorsomedial prefrontal cortices (dmPFC) implicated in emotion control. Conversely, attenuated amygdala activity for task-relevant and irrelevant positive cues was observed in depressed participants. In Study 2, effortful emotion regulation using strategies adapted from cognitive behaviour therapy (CBT) revealed greater activity in regions of the dorsal and lateral prefrontal cortices in both MDD and control participants when attempting to either down-regulate negative or up-regulate positive emotions. During the down-regulation of negative cues, only controls displayed a significant reduction of amygdala activity. In Study 3, an individual differences approach using multiple regression revealed that while greater amygdala-vmPFC structural connectivity was associated with low trait-anxiety, greater connectivity between amygdala and regions of occipitotemporal and parietal cortices was associated with high trait-anxiety. These findings are discussed with respect to current models of emotional reactivity and emotion control derived from studies of both healthy individuals and those with emotional disorders, particularly depression. The focus is on amygdala variability in differing contexts, the role of the vmPFC in the modulation of amygdala activity via learning processes, and the modulation of emotion by attention or cognitive control mechanisms initiated by regions of frontoparietal cortices

Socio-emotional Functioning in Bipolar Disorder Versus Typical Development: Behavioral and Neural Differences

Socio-emotional dysfunction is a core feature of bipolar disorder (BD) across the lifespan. Recent evidence indicates associations between this atypical functioning and the presence of neurally-based anomalies. This article critically reviews the literature on two types of core socioemotional skills that may represent endophenotypes for BD, with a focus on differences between individuals with BD, both youth and adults, and their typically developing peers. First, it examines studies of social cue perception and interpretation, with an emphasis on behavioral and neural studies of facial expression processing. Second, it shifts to examine behavioral and neural differences in cognitive and behavioral flexibility. Finally, the article summarizes potential future directions for research in this area

Genetic variation in the oxytocin system and its link to social motivation in human infants

Frontal brain asymmetry has been linked to motivational processes in infants and adults, with left lateralization reflecting motivation to approach and right lateralization reflecting motivation to withdraw. We examined the hypothesis that variability in infants’ social motivation may be linked to genetic variation in the oxytocin system. Eleven-month-old infants’ brain responses and looking preferences to smiling and frowning individuals were assessed in conjunction with a polymorphism in CD38 (rs3796863) linked to autism spectrum disorder (ASD) and reduced oxytocin. Frontal brain asymmetry and looking preferences differed as a function of CD38 genotype. While non-risk A-allele carriers displayed left lateralization to smiling faces (approach) and a heightened looking preference for the individual who smiled, infants with the CC (ASD risk) genotype displayed withdrawal from smiling faces and a preference for the individual who frowned. Findings demonstrate that the oxytocin system is linked to brain and behavioral markers of social motivation in infancy

The effect of self-referential expectation on emotional face processing

The role of self-relevance has been somewhat neglected in static face processing paradigms but may be important in understanding how emotional faces impact on attention, cognition and affect. The aim of the current study was to investigate the effect of self-relevant primes on processing emotional composite faces. Sentence primes created an expectation of the emotion of the face before sad, happy, neutral or composite face photos were viewed. Eye movements were recorded and subsequent responses measured the cognitive and affective impact of the emotion expressed. Results indicated that primes did not guide attention, but impacted on judgments of valence intensity and self-esteem ratings. Negative self-relevant primes led to the most negative self-esteem ratings, although the effect of the prime was qualified by salient facial features. Self-relevant expectations about the emotion of a face and subsequent attention to a face that is congruent with these expectations strengthened the affective impact of viewing the face

A Review on EEG Signals Based Emotion Recognition

Emotion recognition has become a very controversial issue in brain-computer interfaces (BCIs). Moreover, numerous studies have been conducted in order to recognize emotions. Also, there are several important definitions and theories about human emotions. In this paper we try to cover important topics related to the field of emotion recognition. We review several studies which are based on analyzing electroencephalogram (EEG) signals as a biological marker in emotion changes. Considering low cost, good time and spatial resolution, EEG has become very common and is widely used in most BCI applications and studies. First, we state some theories and basic definitions related to emotions. Then some important steps of an emotion recognition system like different kinds of biologic measurements (EEG, electrocardiogram [EEG], respiration rate, etc), offline vs online recognition methods, emotion stimulation types and common emotion models are described. Finally, the recent and most important studies are reviewed

Social Cognition and Cognitive Flexibility in Bipolar Disorder

Considerable evidence indicates that acquisition and implementation of an array of social cognitive and behavioral skills are disrupted in the context of this psychiatric illness. Furthermore, numerous studies link the social deficits evident in bipolar disorder (BD) with atypical development in brain regions implicated in social and emotional processing. Elucidating the social disruptions evident across the life span in individuals with BD, how these disruptions relate to specific behavioral deficits or endophenotypes, and their underlying neural mechanisms may help inform our understanding not only of psychopathological processes but also of typical social development at the behavioral and neural levels. Additionally, clarification of social deficits and strengths associated with BD, as well as their neural underpinnings, may facilitate the development of effective and explicitly targeted interventions

Discriminative power of EEG-based biomarkers in major depressive disorder: A systematic review

Currently, the diagnosis of major depressive disorder (MDD) and its subtypes is mainly based on subjective assessments and self-reported measures. However, objective criteria as Electroencephalography (EEG) features would be helpful in detecting depressive states at early stages to prevent the worsening of the symptoms. Scientific community has widely investigated the effectiveness of EEG-based measures to discriminate between depressed and healthy subjects, with the aim to better understand the mechanisms behind the disorder and find biomarkers useful for diagnosis. This work offers a comprehensive review of the extant literature concerning the EEG-based biomarkers for MDD and its subtypes, and identify possible future directions for this line of research. Scopus, PubMed and Web of Science databases were researched following PRISMA’s guidelines. The initial papers’ screening was based on titles and abstracts; then full texts of the identified articles were examined, and a synthesis of findings was developed using tables and thematic analysis. After screening 1871 articles, 76 studies were identified as relevant and included in the systematic review. Reviewed markers include EEG frequency bands power, EEG asymmetry, ERP components, non-linear and functional connectivity measures. Results were discussed in relations to the different EEG measures assessed in the studies. Findings confirmed the effectiveness of those measures in discriminating between healthy and depressed subjects. However, the review highlights that the causal link between EEG measures and depressive subtypes needs to be further investigated and points out that some methodological issues need to be solved to enhance future research in this field

An Electrophysiological Examination of Attentional Biases to Emotional Faces in Depression and Social Anxiety

Cognitive theories have proposed that major depressive disorder (MDD) and social anxiety disorder (SAD) involve attentional biases toward and away from specific environmental stimuli. Research has often examined these biases in response to emotional facial expressions, but evidence of attentional biases is mixed. An event-related potential called the N2pc offers advantages over other measures of attentional bias and may clarify conflicting findings. Studies on the N2pc and social anxiety have found consistent results, but there is little work examining depression. Previous N2pc studies are limited by the types of emotional faces they use and by comparing attention for emotional faces only with neutral faces. Further, the effect of MDD-SAD comorbidity has not been thoroughly examined using the N2pc. In this study, undergraduate participants completed self-report questionnaires of depression and social anxiety symptoms. Electroencephalography and reaction time (RT) data were collected during a modified dot-probe task that put emotional faces (angry, disgust, sad, and happy) in direct competition with each other and with neutral faces. ANCOVAs predicting the N2pc and RT showed that no depression or social anxiety-related attentional biases were stronger for any one face type relative to biases for the other face types. However, multiple regressions predicting attentional bias toward specific face type showed that depression and social anxiety interacted to predict attentional biases. Depression was associated with an N2pc attentional bias toward sad faces when social anxiety was low. Social anxiety was related to an N2pc attentional bias away from angry faces at low depression and towards angry faces at high depression, and there was an RT attentional bias away from disgust faces at low depression. Additionally, depression was related to an attentional bias away from neutral faces, while social anxiety was related to a bias toward them. These findings bolster evidence of a sad-related bias in depression and social threat-related biases in social anxiety but highlight the generally overlooked impact of co-occurring symptoms. Interventions for MDD and SAD should target attentional biases in a nuanced manner that considers comorbidity and patterns of both vigilance for and avoidance of social stimuli

Neurogenetics of emotion processing in major depression

Die vorliegende Arbeit charakterisiert neurogenetische Mechanismen der Depression. In einer ersten Studie wurden neurobiologische Korrelate der automatischen Emotionsverarbeitung bei Depressiven mittels fMRT untersucht. Es zeigte sich, dass Depressive im Vergleich mit Gesunden eine Hyperresponsivität der Amygdala auf negative Reize zeigen, jedoch eine Hyporesponsivität auf positive Reize. In einer zweiten Studie konnte gezeigt werden, dass ein derartiges Muster mit einer genetischen Variante im Serotonintransportergen (5-HTTLPR) assoziiert ist. In einem dritten Experiment wurde eine genetische Variante im Neuropeptid Y Gen untersucht. Die depressiven Träger von Risikoallelen, die mit einem schlechten Ansprechen auf Pharmakotherapie assoziiert sind, zeigten ebenfalls ein Muster von gesteigerter Amygdalaresponsivität auf bedrohliche Gesichter. Dieser Forschungsansatz schlägt eine Brücke zwischen kleinen Effekten einzelner genetischer Varianten und komplexen psychiatrischen Phänotypen