Men fear other men most: Gender specific brain activations in perceiving threat from dynamic faces and bodies. An fMRI study.

We report a functional magnetic resonance imaging experiment showing different activation patterns as a function of threatening signals from facial or bodily expressions and these differed between male and female participants as a function of male and female actors. Male observers showed a clear motor preparation response to threatening male body language

Threat Prompts Defensive Brain Responses Independently of Attentional Control

Negative emotional signals are known to influence task performance, but so far, investigations have focused on how emotion interacts with perceptual processes by mobilizing attentional resources. The attention-independent effects of negative emotional signals are less well understood. Here, we show that threat signals trigger defensive responses independently of what observers pay attention to. Participants were scanned using functional magnetic resonance imaging while watching short video clips of threatening actions and performed either color or emotion judgments. Seeing threatening actions interfered with performance in both tasks. Amygdala activation reflected both stimulus and task conditions. In contrast, threat stimuli prompted a constant activity in a network underlying reflexive defensive behavior (periaqueductal gray, hypothalamus, and premotor cortex). Threat stimuli also disrupted ongoing behavior and provoked motor conflict in prefrontal regions during both tasks. The present results are consistent with the view that emotions trigger adaptive action tendencies independently of task setting

Cumulative activation during positive and negative events and state anxiety predicts subsequent inertia of amygdala reactivity

Inertia, together with intensity and valence, is an important component of emotion. We tested whether positive and negative events generate lingering changes in subsequent brain responses to unrelated threat stimuli and investigated the impact of individual anxiety. We acquired fMRI data while participants watched positive or negative movie-clips and subsequently performed an unrelated task with fearful and neutral faces. We quantified changes in amygdala reactivity to fearful faces as a function of the valence of preceding movies and cumulative neural activity evoked during them. We demonstrate that amygdala responses to emotional movies spill over to subsequent processing of threat information in a valence-specific manner: negative movies enhance later amygdala activation whereas positive movies attenuate it. Critically, the magnitude of such changes is predicted by a measure of cumulative amygdala responses to the preceding positive or negative movies. These effects appear independent of overt attention, are regionally limited to amygdala, with no changes in functional connectivity. Finally, individuals with higher state anxiety displayed stronger modulation of amygdala reactivity by positive movies. These results suggest that intensity and valence of emotional events as well as anxiety levels promote local changes in amygdala sensitivity to threat, highlighting the importance of past experience in shaping future affective reactivit

The role of the subgenual anterior cingulate cortex in dorsomedial prefrontal-amygdala neural circuitry during positive-social emotion regulation

Positive-social emotions mediate one's cognitive performance, mood, well-being, and social bonds, and represent a critical variable within therapeutic settings. It has been shown that the upregulation of positive emotions in social situations is associated with increased top-down signals that stem from the prefrontal cortices (PFC) which modulate bottom-up emotional responses in the amygdala. However, it remains unclear if positive-social emotion upregulation of the amygdala occurs directly through the dorsomedial PFC (dmPFC) or indirectly linking the bilateral amygdala with the dmPFC via the subgenual anterior cingulate cortex (sgACC), an area which typically serves as a gatekeeper between cognitive and emotion networks. We performed functional MRI (fMRI) experiments with and without effortful positive-social emotion upregulation to demonstrate the functional architecture of a network involving the amygdala, the dmPFC, and the sgACC. We found that effortful positive-social emotion upregulation was associated with an increase in top-down connectivity from the dmPFC on the amygdala via both direct and indirect connections with the sgACC. Conversely, we found that emotion processes without effortful regulation increased network modulation by the sgACC and amygdala. We also found that more anxious individuals with a greater tendency to suppress emotions and intrusive thoughts, were likely to display decreased amygdala, dmPFC, and sgACC activity and stronger connectivity strength from the sgACC onto the left amygdala during effortful emotion upregulation. Analyzed brain network suggests a more general role of the sgACC in cognitive control and sheds light on neurobiological informed treatment interventions

Neuro-imagerie et neuroscience des émotions

Les neurosciences portent un intérêt croissant à l’étude des processus affectifs et sociaux chez l’homme et l’animal. Quels sont les cadres théoriques de ces recherches et leurs méthodes ? Quels résultats ont-elles déjà permis d’obtenir ? Quels objectifs souhaitent-elles atteindre ? Enfin, comment ces résultats peuvent-ils servir à une meilleure compréhension de certaines pathologies psychiatriques ? Cette revue offre un résumé synthétique des connaissances actuelles sur ces questions

Neuroanatomie fonctionnelle de la perception de signaux émotionnels (reconnaître la peur et la colère dans les actions d'autrui)

La lecture des comportements moteurs joue un rôle essentiel dans la faculté de comprendre les actions d autrui et participe à la régulation des interactions sociales. L implémentation des fonctions cérébrales responsables de l extraction des signaux affectifs au travers des actions que nous percevons reste néanmoins mal comprise, notamment concernant le rôle joué par les régions motrices et frontales. L objectif général de ce projet vise à étudier les substrats cérébraux impliqués dans la perception des affects d autrui, en particulier la peur et la colère. En guise d hypothèse, nous avons considéré que l exposition à des actions signalant une menace potentielle prépare l observateur à réagir de façon adaptée. A l aide de l imagerie par résonance magnétique fonctionnelle, nous avons souhaité : i) identifier les corrélats cérébraux associés à l observation passive d actions signalant la peur et la colère, et étudier l influence du mouvement sur l activité de ces réseaux ; ii) examiner les traitements communs et spécifiques à la reconnaissance de signaux de peur et de colère ; iii) étudier l influence de l attention sur l activité des régions impliquées durant ces tâches. Nous observons un réseau de régions temporales (STS, TPJ, amygdale & pôle temporal) et frontales (BA45/BA47, vmPFC & arMFC) qui sont modulées par les facteurs émotionnels et attentionnels. Ce réseau apparaît impliqué dans l évaluation affective des actions. L activité de l hypothalamus, de la substance grise périaqueductale et du cortex prémoteur dorsal, qui répondent également à l observation de signaux de menace, est indépendante du facteur attentionnel. Chez l animal, ces régions participent à l organisation de comportements défensifs, ce qui suggère que l observation de comportements menaçants déclenche des réponses adaptées chez l observateur. Enfin, ces résultats soulèvent des questions concernant le rôle du lobe frontal (BA47 & arMFC) dans la régulation des affects et du comportement en situation d interaction sociale.The reading of motor behaviors plays an essential role for understanding other s actions and regulation of social interactions. The implementation of cerebral functions responsible for the extraction of emotional signals from other s actions remains unclear, notably concerning the role of motor and frontal regions. This project aims to understand the cerebral substrates involved in perceiving other s emotions, in particular fear and anger. We hypothesize that exposure to actions signaling a potential threat triggers an adaptive response in the observer. Using functional magnetic resonance imaging, we aim to: i) identify the regions associated with the passive observation of actions signaling fear and anger and study the influence of movement on their activity; ii) investigate treatments that are common and specific to the recognition of fear and anger signals; iii) study how attention influences the activity of regions engaged during such tasks. We observe a network of temporal (STS, TPJ, amygdala & temporal pole) and frontal regions (BA45/BA47, vmPFC & arMFC) that are modulated by emotional and attentional factors, and it appears to be involved in evaluating the affective significance of actions. The activity of the hypothalamus, periaqueductal gray and dorsal premotor cortex, which also responds to threat signals, remains unaffected by the focus of attention in the task. In animals, these regions are known to participate in the organization of defensive behaviors, which suggests that the observation of threatening behaviors triggers adaptive responses in the observer. Finally, these results raise questions regarding the role of the frontal lobe (BA47 & arMFC) in regulating affects and behavior in the contextof social interaction.PARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF

Emotional regulation and attentional processes

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