Neurocognitive Mechanisms of Fear Conditioning and Vulnerability to Anxiety

A commentary on Fear-conditioning mechanisms associated with trait vulnerability to anxiety in human

ENIGMA-anxiety working group : Rationale for and organization of large-scale neuroimaging studies of anxiety disorders

Altres ajuts: Anxiety Disorders Research Network European College of Neuropsychopharmacology; Claude Leon Postdoctoral Fellowship; Deutsche Forschungsgemeinschaft (DFG, German Research Foundation, 44541416-TRR58); EU7th Frame Work Marie Curie Actions International Staff Exchange Scheme grant 'European and South African Research Network in Anxiety Disorders' (EUSARNAD); Geestkracht programme of the Netherlands Organization for Health Research and Development (ZonMw, 10-000-1002); Intramural Research Training Award (IRTA) program within the National Institute of Mental Health under the Intramural Research Program (NIMH-IRP, MH002781); National Institute of Mental Health under the Intramural Research Program (NIMH-IRP, ZIA-MH-002782); SA Medical Research Council; U.S. National Institutes of Health grants (P01 AG026572, P01 AG055367, P41 EB015922, R01 AG060610, R56 AG058854, RF1 AG051710, U54 EB020403).Anxiety disorders are highly prevalent and disabling but seem particularly tractable to investigation with translational neuroscience methodologies. Neuroimaging has informed our understanding of the neurobiology of anxiety disorders, but research has been limited by small sample sizes and low statistical power, as well as heterogenous imaging methodology. The ENIGMA-Anxiety Working Group has brought together researchers from around the world, in a harmonized and coordinated effort to address these challenges and generate more robust and reproducible findings. This paper elaborates on the concepts and methods informing the work of the working group to date, and describes the initial approach of the four subgroups studying generalized anxiety disorder, panic disorder, social anxiety disorder, and specific phobia. At present, the ENIGMA-Anxiety database contains information about more than 100 unique samples, from 16 countries and 59 institutes. Future directions include examining additional imaging modalities, integrating imaging and genetic data, and collaborating with other ENIGMA working groups. The ENIGMA consortium creates synergy at the intersection of global mental health and clinical neuroscience, and the ENIGMA-Anxiety Working Group extends the promise of this approach to neuroimaging research on anxiety disorders

Utvärdering av minnesbaserad kollaborativ rekommendation av Github-projekt

GitHub is host to a huge number of repositories. In order to explore and find new and interesting repositories on GitHub users has to rely on global charts or explore manually. Recommender systems are a type of software algorithms that produce personalized recommendations to users. One class of such algorithms are called memory based collaborative filtering. This report explore whether this kind of algorithms can be used to generate personalized recommendations of repositories on GitHub to its users, which is achieved by evaluating existing methods of generating predictions using memory based collaborative filtering which is then implemented for experimentation. The results indicates that memory based collaborative filtering might be a slightly better choice than global charts for a small percentage of the users, but for most users it is not.Det finns en väldigt stor mängd git-project tillgängliga på GitHub. Om en användare vill upptäcka intressanta projekt måste denne förlita sig på allmänna topplistor alternativt utforska GitHub på egen hand. Rekommendationssystem är en slags mjukvaru algoritmer som kan skapa personligt anpassade rekommendationer till användare. En speciell typ av dessa algoritmer kallas för minnesbaserad kollaborativ rekommendation. Den här avhandlingen ämnar utforska huruvida denna typ av algoritmer kan användas för att rekommendera git-projekt till användare på GitHub. Detta görs genom att utvärdera relevant forskning i området vilket leder till en rad experiment vilka utverderar tillförlitlheten hos ett antal algoritmer. Resultaten från dessa experiment indikerar att minnesbaserad kollaborativ rekommendation är något bättre än allmänna topplistor för en liten grupp av användare på GitHub. För de allra flesta är dock allmänna topplistor ett bättre alternativ

The Amygdala, Arousal and Memory: From Lesions to Neuroimaging

Emotional events are better remembered than neutral events. But what are the mechanisms behind this memory enhancing effect? It seems that they depend on the arousal level at the moment we experience the event to be remembered. The first study of the present thesis mapped the brain areas that changed their activity in a highly arousing situation in subjects with snake or spider phobia. Looking at pictures of their feared object engaged the amygdala, situated in the medial temporal lobe. This area has previously been demonstrated to be necessary for fear reactions. Here, the novel question was what other brain areas the amygdala engages when the brain is in a state of high arousal. Results suggest that the amygdala recruits other limbic and cortical areas known to be involved in motor behavior and object recognition. In contrast, when subjects watched fear-relevant but non-phobic pictures, amygdala activity was negatively correlated to the anterior cingulate cortex suggesting cortical inhibition. The final two studies aimed at explaining the physiological brain mechanisms behind arousal enhancement of memory. In the first one, epileptic patients with medial temporal lobe resections including the amygdala were compared to healthy controls on a recognition memory task where the pictures to be remembered varied in arousal intensities. Results suggested that the anterior medial temporal lobe including the amygdala is necessary for arousal enhancement of memory because the enhancement effect was abolished in resectioned patients. The last study related inter-individual differences in bodily arousal to amygdala-parahippocampal interaction. Results suggest that the beneficial effects of emotion on memory depend on arousal regulating mechanisms of the amygdala that in turn affects parahippocampal activity. Collectively, results suggest that the amygdala is regulating changes in arousal states of the brain and body during distressful situations. Further, arousal in turn determines memory strength through gating amygdala influences on the parahippocampal cortex. Thus, the amygdala is a node both in a fear and a memory network and arousal influences the amygdala to prepare for action and to enhance memory. This seems evolutionary sound.

The Amygdala, Arousal and Memory: From Lesions to Neuroimaging

Emotional events are better remembered than neutral events. But what are the mechanisms behind this memory enhancing effect? It seems that they depend on the arousal level at the moment we experience the event to be remembered. The first study of the present thesis mapped the brain areas that changed their activity in a highly arousing situation in subjects with snake or spider phobia. Looking at pictures of their feared object engaged the amygdala, situated in the medial temporal lobe. This area has previously been demonstrated to be necessary for fear reactions. Here, the novel question was what other brain areas the amygdala engages when the brain is in a state of high arousal. Results suggest that the amygdala recruits other limbic and cortical areas known to be involved in motor behavior and object recognition. In contrast, when subjects watched fear-relevant but non-phobic pictures, amygdala activity was negatively correlated to the anterior cingulate cortex suggesting cortical inhibition. The final two studies aimed at explaining the physiological brain mechanisms behind arousal enhancement of memory. In the first one, epileptic patients with medial temporal lobe resections including the amygdala were compared to healthy controls on a recognition memory task where the pictures to be remembered varied in arousal intensities. Results suggested that the anterior medial temporal lobe including the amygdala is necessary for arousal enhancement of memory because the enhancement effect was abolished in resectioned patients. The last study related inter-individual differences in bodily arousal to amygdala-parahippocampal interaction. Results suggest that the beneficial effects of emotion on memory depend on arousal regulating mechanisms of the amygdala that in turn affects parahippocampal activity. Collectively, results suggest that the amygdala is regulating changes in arousal states of the brain and body during distressful situations. Further, arousal in turn determines memory strength through gating amygdala influences on the parahippocampal cortex. Thus, the amygdala is a node both in a fear and a memory network and arousal influences the amygdala to prepare for action and to enhance memory. This seems evolutionary sound.

The Amygdala, Arousal and Memory: From Lesions to Neuroimaging

Emotional events are better remembered than neutral events. But what are the mechanisms behind this memory enhancing effect? It seems that they depend on the arousal level at the moment we experience the event to be remembered. The first study of the present thesis mapped the brain areas that changed their activity in a highly arousing situation in subjects with snake or spider phobia. Looking at pictures of their feared object engaged the amygdala, situated in the medial temporal lobe. This area has previously been demonstrated to be necessary for fear reactions. Here, the novel question was what other brain areas the amygdala engages when the brain is in a state of high arousal. Results suggest that the amygdala recruits other limbic and cortical areas known to be involved in motor behavior and object recognition. In contrast, when subjects watched fear-relevant but non-phobic pictures, amygdala activity was negatively correlated to the anterior cingulate cortex suggesting cortical inhibition. The final two studies aimed at explaining the physiological brain mechanisms behind arousal enhancement of memory. In the first one, epileptic patients with medial temporal lobe resections including the amygdala were compared to healthy controls on a recognition memory task where the pictures to be remembered varied in arousal intensities. Results suggested that the anterior medial temporal lobe including the amygdala is necessary for arousal enhancement of memory because the enhancement effect was abolished in resectioned patients. The last study related inter-individual differences in bodily arousal to amygdala-parahippocampal interaction. Results suggest that the beneficial effects of emotion on memory depend on arousal regulating mechanisms of the amygdala that in turn affects parahippocampal activity. Collectively, results suggest that the amygdala is regulating changes in arousal states of the brain and body during distressful situations. Further, arousal in turn determines memory strength through gating amygdala influences on the parahippocampal cortex. Thus, the amygdala is a node both in a fear and a memory network and arousal influences the amygdala to prepare for action and to enhance memory. This seems evolutionary sound.

Artificial Intelligence Supported Cognitive Behavioral Therapy for Treatment of Speech Anxiety in Virtual Reality Environments

Cognitive behavioral therapy (CBT) has become a successful treatment to improve management of stress and anxiety in social situations. One of the most widespread social anxiety disorders is speech anxiety, and there are also studies reporting that speech anxiety is increasing among younger adults. An emerging trend in CBT treatment is virtual reality (VR), a technology that today also could involve the use of artificial intelligence. The aim of this position paper is to present and discuss the idea of using explainable artificial intelligence to improve CBT treatment of speech anxiety in virtual reality environments.   The proposed CBT and VR concept builds upon identification of individuals for whom a scientifically grounded treatment can be predicted to have a larger effect than the average. The identification of these individuals should be conducted with the use of Explainable artificial intelligence (XAI). However, the effect of providing XAI-based information on actual treatment outcome has not been fully investigated and established. To better understand how AI-based information can strengthen CBT, it would be valuable to investigate how much confidence individuals undergoing treatment can have in information that is derived from XAI applications. If XAI-derived information is trusted to the same extent as traditional information coming from psychologists, this could open up for CBT design. Furthermore, the VR-treatment should be grounded in learning theory and cognitive psychology with an emphasis on promotion of inhibitory learning.  A commercial application should be used for stimuli presentation in the VR-head-set based on various scenarios that simulates real-world situations. The main objective of the VR-treatment is to promote inhibitory learning by disproving catastrophic beliefs through exposure to distressful speech situations. Outcomes of the treatment should primarily be measured by the Public Speaking Anxiety Scale, but also involve an assessment of social anxiety with the use of Liebowitz’s Social Anxiety Scale

Whole brain correlates of individual differences in skin conductance responses during discriminative fear conditioning to social cues.

Understanding the neural basis for individual differences in the skin conductance response (SCR) during discriminative fear conditioning may inform on our understanding of autonomic regulation in fear-related psychopathology. Previous region-of-interest (ROI) analyses have implicated the amygdala in regulating conditioned SCR, but whole brain analyses are lacking. This study examined correlations between individual differences in SCR during discriminative fear conditioning to social stimuli and neural activity throughout the brain, by using data from a large functional magnetic resonance imaging study of twins (N = 285 individuals). Results show that conditioned SCR correlates with activity in the dorsal anterior cingulate cortex/anterior midcingulate cortex, anterior insula, bilateral temporoparietal junction, right frontal operculum, bilateral dorsal premotor cortex, right superior parietal lobe, and midbrain. A ROI analysis additionally showed a positive correlation between amygdala activity and conditioned SCR in line with previous reports. We suggest that the observed whole brain correlates of SCR belong to a large-scale midcingulo-insular network related to salience detection and autonomic-interoceptive processing. Altered activity within this network may underlie individual differences in conditioned SCR and autonomic aspects of psychopathology

The effect of immersive virtual reality on proximal and conditioned threat

Virtual reality lets the user be immersed in a 3-dimensional environment, which can enhance certain emotional responses to stimuli relative to experiencing them on a flat computer screen. We here tested whether displaying two different types of threats in immersive virtual reality enhanced threat related autonomic responses measured by skin conductance responses (SCRs). We studied innate and learned threat responses because these types of threats have been shown to depend on different neural circuits in animals. Therefore, it is possible that immersive virtual reality may modulate one of these threats but not the other. Innate threat responses were provoked by the sudden appearance of characters at proximal egocentric distance, which were compared to the sudden appearance of distant characters (proximal threat). Learned threat responses were studied by conditioning two of the characters to an electric shock (conditioned threat) and contrasting SCRs to these characters with SCRs to two other characters that were never paired with shock. We found that displaying stimuli in immersive virtual reality enhanced proximal threat responses but not conditioned threat responses. Findings show that immersive virtual reality can enhance an innate type of threat responses without affecting a learned threat response, suggesting that separate neural pathways serve these threat responses. This article is licensed under a Creative Commons Attribution 4.0 International License, http://creativecommons.org/licenses/by/4.0/.</p