Emmanuelle Reynaud

Dissociating Bottom-Up and Top-Down Mechanisms in the Cortico-Limbic System during Emotion Processing

The cortico-limbic system is critically involved in emotional responses and resulting adaptive behaviors. Within this circuit, complementary regions are believed to be involved in either the appraisal or the regulation of affective state. However, the respective contribution of these bottom-up and top-down mechanisms during emotion processing remains to be clarified. We used a new functional magnetic resonance imaging (fMRI) paradigm varying 3 parameters: emotional valence, emotional congruency, and allocation of attention, to distinguish the functional variation in activity and connectivity between amygdala, anterior cingulate cortex (ACC), and dorsolateral prefrontal cortex (DLPFC). Bottom-up appraisal of negative compared with positive stimuli led to a greater amygdala response and stronger functional interaction between amygdala and both dorsal ACC and DLPFC. Top-down resolution of emotional conflict was associated with increased activity within ACC and higher functional connectivity between this structure, and both the amygdala and DLPFC. Finally, increased top-down attentional control caused greater engagement of the DLPFC, accompanied by increased connectivity between DLPFC and dorsal ACC. This novel task provides an efficient tool for exploring bottom-up and top-down processes underlying emotion and may be particularly helpful for investigating the neurofunctional underpinnings of psychiatric disorders.

Relationship between emotional experience and resilience: An fMRI study in fire-fighters

Resilience refers to the capacity to cope effectively in stressful situations or adversity. It may involve the ability to experience emotions matching the demands of environmental circumstances. The brain mechanisms underlying resilience remain unclear. In this study, we aim to investigate the relationship between the neural basis of emotional experience and resilience. Thirty-six fire-fighters were included. They performed an fMRI script-driven paradigm comprising relaxing and trauma-related scripts to evaluate the cerebral substrate of emotional experience (p<0.05, FDR-corrected). Correlations were examined between fMRI activations and the resilience DRS15 scale (p<0.05). Resilience was positively correlated with the right amygdala and left orbitofrontal activations when performing the contrast of trauma vs. relaxing script. The present study provides neural data on the mechanisms underlying resilience and their relationship with emotional reactivity, suggesting that appropriate emotional response in stressful situations is essential for coping with aversive events in daily life.

Effect of trait anxiety on prefrontal control mechanisms during emotional conflict.

Converging evidence points to a link between anxiety proneness and altered emotional functioning, including threat‐related biases in selective attention and higher susceptibility to emotionally ambiguous stimuli. However, during these complex emotional situations, it remains unclear how trait anxiety affects the engagement of the prefrontal emotional control system and particularly the anterior cingulate cortex (ACC), a core region at the intersection of the limbic and prefrontal systems. Using an emotional conflict task and functional magnetic resonance imaging (fMRI), we investigated in healthy subjects the relations between trait anxiety and both regional activity and functional connectivity (psychophysiological interaction) of the ACC. Higher levels of anxiety were associated with stronger task‐related activation in ACC but with reduced functional connectivity between ACC and lateral prefrontal cortex (LPFC). These results support the hypothesis that when one is faced with emotionally incompatible information, anxiety leads to inefficient high‐order control, characterized by insufficient ACC‐LPFC functional coupling and increases, possibly compensatory, in activation of ACC. Our findings provide a deeper understanding of the pathophysiology of the neural circuitry underlying anxiety and may offer potential treatment markers for anxiety disorders. Hum Brain Mapp 36:2207–2214, 2015.

Acute stress disorder modifies cerebral activity of amygdala and prefrontal cortex.

The diagnosis constraint of acute stress disorder (ASD), consisting of testing individuals in the month following trauma exposure, limits research on the very early and initial stage of the disease. In this regard, this work aims to explore the cerebral mechanism of ASD in a population of fire-fighters before and after trauma exposure. Thirty-six healthy non-traumatized male fire-fighters were explored by an fMRI emotional face-matching task to evaluate the cerebral substrate of emotional recognition. During the two years of the follow-up, two subjects were traumatized, and thus retested, as were 10 non-traumatized subjects among the initial non-exposed ones. In comparison to non-exposed subjects, fire-fighters with ASD had enhanced amygdala, orbitofrontal, and dorsolateral prefrontal BOLD responses to fearful and angry faces (p < .05, FDR-corrected). These results shed new light on the cerebral mechanism associated with ASD. We observed for the first time the existence of an altered fear processing pathway in ASD that is mediated by amygdala and prefrontal cortex hyperactivity, which might be at the core of the disorder.

The secrets of a good winery: core competences

Purpose – This article seeks to examine the ability of a French winery from Anjou (Pays de la Loire) to market its wine locally with higher value added than another local winery through the application of the concept of core competences.Design/methodology/approach – This concept is first explained, and then the two Angevin vineyards analysed in terms of their particular core competences, using interviews.Findings – It is demonstrated that wine quality reflects the presence of core competences and the nature of those core competences is specified.Originality/value – The transcribed material was analysed by thematic content in order to evaluate the process for creating competences.

Brain metabolism and related connectivity in patients with acrophobia treated by virtual reality therapy: an 18F-FDG PET pilot study sensitized by virtual exposure

BackgroundThe aim of this pilot study is to investigate the impact of virtual reality exposure therapy (VRET) on brain metabolism and connectivity.Eighteen patients with acrophobia were assessed by an 18F-FDG PET scan sensitized by virtual exposure before treatment, and nine of them were assessed again after eight sessions of VRET. Statistical Parametric Mapping was used to study the correlations between metabolism and pretherapeutic clinical scores and to compare metabolism before and after VRET (p voxel < 0.005, corrected for cluster volume). Metabolic connectivity was evaluated through interregional correlation analysis.ResultsBefore therapy, a positive correlation was found between scores on the behavioural avoidance test and left occipital metabolism (BA17-18). After VRET, patients presented increased metabolism in the left frontal superior gyri and the left precentral gyrus, which showed increased metabolic connectivity with bilateral occipital areas (BA17-18-19), concomitant with clinical recovery.ConclusionsThis study highlights the exciting opportunity to use brain PET imaging to investigate metabolism during virtual exposure and reports the involvement of the visual-motor control system in the treatment of acrophobia by VRET.

EPA-0789 – Dissociating bottom-up and top-down mechanisms in the cortico-limbic system during emotion processing

The cortico-limbic system, critically involved in emotional responses, has become increasingly central to models of psychopathology. Indeed, most psychiatric disorders are believed to be defined by some level of dysfunction in this circuit such as exacerbated limbic activity and/or inefficient prefrontal control. We here propose a novel functional magnetic resonance imaging (fMRI) paradigm, the VAAT (Variable Attention And congruency Task) which intends to dissociate bottom-up from top-down subnetworks within the cortico-limbic circuit. Twenty-six healthy volunteers completed psychometric assessments and the VAAT Task. In this task, activity as well as connectivity between the amygdala, the anterior cingulate cortex (ACC) and the dorsolateral prefrontal cortex (DLPFC) was tested by varying three parameters: emotional valence, emotional congruency and attention load respectively. Functional relevance of this circuit was examined through multiple correlations analyses between BOLD/PPI (psychophysiological interactions) measures and trait anxiety, as assessed by The State-Trait-Anxiety Inventory (STAI). The amygdala, and its connections to DLPFC and dorsal ACC, was engaged in bottom-up emotional processing. ACC, and its connections to DLPFC and amygdala, was preferentially recruited in top-down resolution of emotional conflict. DLPFC, and its connections to dorsal ACC, was engaged in top-down attentional control. In addition, trait anxiety was associated with increased ACC and DLPFC activity but decreased functional connectivity between these two regions. This novel task provides a useful tool for exploring bottom-up and top-down processes underlying emotion. Furthermore, our findings suggest that trait anxiety is associated with less efficient connectivity in the higher-order cortical circuit involved in emotion regulation.

Discours sur la RSE dans le processus de légitimation de la banque

Cet article empirique, base sur les rapports des banques francaises de 2004 a 2011, apprehende la facon dont les banques cherchent a recuperer de la legitimite, suite a la crise bancaire de 2008, grâce a la responsabilite sociale de l’entreprise. Deux resultats principaux se degagent. D’une part, les banques communiquent davantage sur leurs responsabilites sectorielles depuis la crise bancaire. D’autre part, et de facon plus etonnante, dans ce secteur fortement institutionnalise, on n’observe pas de comportements isomorphes : les dynamiques de legitimation restent differenciees.

482 – Amygdala activity correlates with attentional bias in PTSD

Post-traumatic stress disorder (PTSD) is an anxiety disorder that arises in the aftermath of a traumatic event. The most prevalent hypothesis is that of an increased amygdala activity to threat cues. The amygdala has also shown an implication in orienting attention toward threat. The aim of this study was to explore the correlations between amygdala activity, symptom severity and attentional bias to threat. PTSD patients and healthy controls were assayed on an fMRI emotional face matching task and an attentional detection of target (DOT) task. The amygdala showed enhanced activity in PTSD patients (vs. healthy individuals). It positively correlated with anxiety scores and PTSD symptoms. It also positively correlated with the disengagement index during the attentional DOT task. Mostly, these results provide preliminary support for an implication of the amygdala in attention orientation to threat in PTSD, whereby in patients amygdala hyperactivity would cause attentional biases, which in turn would induce anxious symptomatology. These results are further discussed in light of recent theories concerned with cortico-limbic functioning and clinical implications.