Acute aerobic exercise enhances pleasant compared to unpleasant visual scene processing

Although acute aerobic exercise benefits different aspects of emotional functioning, it is unclear how exercise influences the processing of emotional stimuli and which brain mechanisms support this relationship. We assessed the influence of acute aerobic exercise on valence biases (preferential processing of negative/positive pictures) by performing source reconstructions of participants’ brain activity after they viewed emotional scenes. Twenty-four healthy participants (12 women) were tested in a randomized and counterbalanced design that consisted of three experimental protocols, each lasting 30 min: low-intensity exercise (Low-Int); moderate-intensity exercise (Mod-Int); and a seated rest condition (REST). After each of the protocols, participants viewed negative and positive pictures, during which event-related magnetic fields were recorded. Analyses revealed that exercise strongly impacted the valence processing of emotional scenes within a widely distributed left hemispheric spatio-temporal cluster between 190 and 310 ms after picture onset. Brain activity in this cluster showed that a negativity bias at REST (negative > positive picture processing) diminished after the Low-Int condition (positive = negative) and even reversed to a positivity bias after the Mod-Int condition (positive > negative). Thus, acute aerobic exercise of low and moderate intensities induces a positivity bias which is reflected in early, automatic processes

Noninvasive stimulation of the ventromedial prefrontal cortex modulates rationality of human decision-making

The framing-effect is a bias that affects decision-making depending on whether the available options are presented with positive or negative connotations. Even when the outcome of two choices is equivalent, people have a strong tendency to avoid the negatively framed option. The ventromedial prefrontal cortex (vmPFC) is crucial for rational decision-making, and dysfunctions in this region have been linked to cognitive biases, impulsive behavior and gambling addiction. Using a financial decision-making task in combination with magnetoencephalographic neuroimaging, we show that excitatory compared to inhibitory non-invasive transcranial direct current stimulation (tDCS) of the vmPFC reduces framing-effects while improving the assessment of loss-probabilities, ultimately leading to increased overall gains. Behavioral and neural data consistently suggest that this improvement in rational decision-making is predominately due to an attenuation of biases towards negative affect (loss-aversion and risk-aversion). These findings recommend further research towards clinical applications of vmPFC-tDCS as in addictive disorders

Non-invasive stimulation reveals ventromedial prefrontal cortex function in reward prediction and reward processing

IntroductionStudies suggest an involvement of the ventromedial prefrontal cortex (vmPFC) in reward prediction and processing, with reward-based learning relying on neural activity in response to unpredicted rewards or non-rewards (reward prediction error, RPE). Here, we investigated the causal role of the vmPFC in reward prediction, processing, and RPE signaling by transiently modulating vmPFC excitability using transcranial Direct Current Stimulation (tDCS).MethodsParticipants received excitatory or inhibitory tDCS of the vmPFC before completing a gambling task, in which cues signaled varying reward probabilities and symbols provided feedback on monetary gain or loss. We collected self-reported and evaluative data on reward prediction and processing. In addition, cue-locked and feedback-locked neural activity via magnetoencephalography (MEG) and pupil diameter using eye-tracking were recorded.ResultsRegarding reward prediction (cue-locked analysis), vmPFC excitation (versus inhibition) resulted in increased prefrontal activation preceding loss predictions, increased pupil dilations, and tentatively more optimistic reward predictions. Regarding reward processing (feedback-locked analysis), vmPFC excitation (versus inhibition) resulted in increased pleasantness, increased vmPFC activation, especially for unpredicted gains (i.e., gain RPEs), decreased perseveration in choice behavior after negative feedback, and increased pupil dilations.DiscussionOur results support the pivotal role of the vmPFC in reward prediction and processing. Furthermore, they suggest that transient vmPFC excitation via tDCS induces a positive bias into the reward system that leads to enhanced anticipation and appraisal of positive outcomes and improves reward-based learning, as indicated by greater behavioral flexibility after losses and unpredicted outcomes, which can be seen as an improved reaction to the received feedback

Noninvasive Stimulation of the Ventromedial Prefrontal Cortex Indicates Valence Ambiguity in Sad Compared to Happy and Fearful Face Processing

The ventromedial prefrontal cortex (vmPFC) is known to be specifically involved in the processing of stimuli with pleasant, rewarding meaning to the observer. By the use of non-invasive transcranial direct current stimulation (tDCS), it was previously possible to show evidence for this valence specificity and to modulate the impact of the vmPFC on emotional network processing. Prior results showed increased neural activation during pleasant relative to unpleasant stimulus processing after excitatory compared to inhibitory vmPFC-tDCS. As dysfunctional vmPFC activation patterns are associated with major depressive disorder (MDD), tDCS of this region could render an attractive application in future therapy. Here, we investigated vmPFC-tDCS effects on sad compared to happy face processing, as sad faces are often used in the study of mood disorders. After counterbalanced inhibitory or excitatory tDCS, respectively, healthy participants viewed happy and sad faces during magnetoencephalography (MEG) recording. In addition, tDCS effects on an interpretational bias of ambiguous happy-sad face morphs and an attentional bias of a dot-probe task with happy and sad faces as emotional primes were investigated. Finally, in conjoint analyses with data from a previous sibling study (happy and fearful faces) we examined whether excitatory vmPFC-tDCS would reveal a general increase in processing of pleasant stimuli independent of the type of unpleasant stimuli applied (sad vs. fearful faces). MEG and behavioral results showed that happy faces promoted a relative positivity bias after excitatory compared to inhibitory tDCS, visible in left orbitofrontal cortex and in the emotion-primed dot-probe task. A converse pattern in the MEG data during sad face processing suggests the possible involvement of an empathy network and thus significantly differed from neuronal processing of fearful face processing. Implications for the bearing of vmPFC modulation on emotional face processing and the impact of specific unpleasant face expressions are discussed

Neural processing of emotional facial stimuli in specific phobia: An fMRI study

Background Patients with specific phobia (SP) show altered brain activation when confronted with phobia-specific stimuli. It is unclear whether this pathogenic activation pattern generalizes to other emotional stimuli. This study addresses this question by employing a well-powered sample while implementing an established paradigm using nonspecific aversive facial stimuli. Methods N = 111 patients with SP, spider subtype, and N = 111 healthy controls (HCs) performed a supraliminal emotional face-matching paradigm contrasting aversive faces versus shapes in a 3-T magnetic resonance imaging scanner. We performed region of interest (ROI) analyses for the amygdala, the insula, and the anterior cingulate cortex using univariate as well as machine-learning-based multivariate statistics based on this data. Additionally, we investigated functional connectivity by means of psychophysiological interaction (PPI). Results Although the presentation of emotional faces showed significant activation in all three ROIs across both groups, no group differences emerged in all ROIs. Across both groups and in the HC > SP contrast, PPI analyses showed significant task-related connectivity of brain areas typically linked to higher-order emotion processing with the amygdala. The machine learning approach based on whole-brain activity patterns could significantly differentiate the groups with 73% balanced accuracy. Conclusions Patients suffering from SP are characterized by differences in the connectivity of the amygdala and areas typically linked to emotional processing in response to aversive facial stimuli (inferior parietal cortex, fusiform gyrus, middle cingulate, postcentral cortex, and insula). This might implicate a subtle difference in the processing of nonspecific emotional stimuli and warrants more research furthering our understanding of neurofunctional alteration in patients with SP.Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659Peer Reviewe

Der Einsatz von Virtueller Realität in der Psychotherapeutischen Praxis: Aktueller Forschungsstand, Chancen, Risiken und Herausforderungen

<jats:title>Zusammenfassung</jats:title><jats:p>In den letzten Jahren sind durch die Fortschritte der Digitalisierung neue psychotherapeutische Behandlungsmöglichkeiten und Unterstützungsangebote entstanden. Während sich bestimmte Innovationen wie die Videotherapie im letzten Jahr stark verbreitet haben, sind andere Formate wie z. B. Psychotherapieanwendungen in der Virtuellen Realität (VR) zwar sehr gut wissenschaftlich untersucht, aber dennoch kaum in die (tägliche) Praxis implementiert worden.</jats:p><jats:p>Der folgende Artikel gibt einen Überblick über den aktuellen Forschungsstand zum Einsatz von VR im Kontext Psychotherapie. Hierbei wird auf zwei wichtige (kognitiv-verhaltenstherapeutische) Interventionsmethoden fokussiert, bei denen VR oft eingesetzt und untersucht wurde: (1) Behaviorale Exposition bei Angsterkrankungen und (2) Modifikation von Informationsverarbeitungsprozessen (Cognitive Bias Modification, CBM). Es werden aktuelle Studien zur Wirksamkeit sowie weitere aktuelle Ergebnisse zur Nutzung und dem Einsatz diskutiert. Weiterhin beschreibt der Artikel die grundsätzliche Nutzung der Virtuellen Realität und definiert wichtige Begriffe und Anwendungen.</jats:p&gt

Self-guided digital treatment with virtual reality for panic disorder and agoraphobia

Finanziert im Rahmen der DEAL-Verträge durch die Universitätsbibliothek SiegenBackground Cognitive behavioral therapy is the first-line treatment for patients with panic disorder (PD) and agoraphobia (AG). Yet, many patients remain untreated due to limited treatment resources. Digital self-guided short-term treatment applications may help to overcome this issue. While some therapeutic applications are already supported by health insurance companies, data on their efficacy is limited. The current study investigates the effect of self-guided digital treatment comprising psychoeducation and virtual reality exposure therapy (VRET). Methods Thirty patients diagnosed with PD, AG, or panic disorder with agoraphobia (PDA) will be randomly assigned to either the experimental group (EG) or the control group (CG). Participants of both groups will undergo baseline diagnostics in the first two sessions. The subsequent treatment for the EG consists of a self-guided 6-week phase of application-based psychoeducation, one therapy session preparing for the VRET, and 4 weeks of application-based self-guided VRET. To control for the potential effects of the therapy session with the therapist, the CG will receive relaxation and stress-reduction training instead. All patients will then undergo a closing session which terminates with the post-assessment (~ 10 weeks after baseline assessment) and a follow-up assessment 6 weeks following the closing session. Symptom severity (primary outcome) will be assessed at baseline, interim, post-treatment, and follow-up. Additionally, remission status (secondary outcome) will be obtained at follow-up. Both measures will be compared between the groups. Discussion The current study aims at providing insights into the efficacy of short-term treatment applications including psychoeducation and self-guided VRET. If successful, this approach might be a feasible and promising way to ease the burden of PD, AG, and PDA on the public health system and contribute to a faster access to treatment

The causal role of prefrontal hemispheric asymmetry in valence processing of words - Insights from a combined cTBS-MEG study

Roesmann K, Dellert T, Junghoefer M, et al. The causal role of prefrontal hemispheric asymmetry in valence processing of words - Insights from a combined cTBS-MEG study. NEUROIMAGE. 2019;191:367-379.Hemispheric asymmetries play an important role in multiple cerebral functions. Asymmetries in prefrontal cortex (PFC) function have been suggested to regulate emotional processing in that right-hemispheric dominance biases towards negative affect, whereas left PFC dominance favors positive affect. This study used transcranial magnetic stimulation to test the causal role of prefrontal asymmetries in the processing of emotional stimuli. To experimentally induce hemispheric asymmetries, 21 healthy volunteers underwent two separate sessions of inhibitory continuous theta burst stimulation (cTBS) to the left versus right dorsolateral prefrontal cortex. Each stimulation was followed by magnetoencephalographic (MEG) recordings of event-related fields elicited by visually presented emotional words in a silent reading task and a subsequent behavioral emotion categorization task. The asymmetry manipulation influenced valence processing of words in early, mid-latency and late time intervals in right occipitotemporal and parietal brain regions. Left-sided cTBS (inducing right-hemispheric dominance) consistently resulted in enhanced brain responses to negative words, while right-sided cTBS (inducing left-hemispheric dominance) enhanced responses to positive words. On a behavioral level, right-hemispheric dominance resulted in more categorization matches of negative compared to positive words, while left-hemispheric dominance resulted in reverse effects. These results provide direct evidence that bottom-up valence processing is influenced by prefrontal hemispheric asymmetry

Self-guided virtual reality therapy for social anxiety disorder

Finanziert im Rahmen der DEAL-Verträge durch die Universitätsbibliothek SiegenBackground Social anxiety disorder (SAD) is a highly prevalent mental disorder associated with enormous stress and suffering. Cognitive behavior therapy (CBT) is the first-line treatment for SAD, yet its accessibility is often constrained with long waiting times. Digital therapeutic applications, including psychoeducation and self-guided behavioral experiments in virtual reality (VR), could facilitate access and reduce waiting times. The study aims to investigate if ultra-short-time therapy involving self-guided digital therapeutic applications with VR components can reduce the severity of SAD. Methods Forty SAD patients will participate in this randomized controlled trial. Half will get access to a self-guided, digital therapeutic application with exposure-based behavioral experiments in VR, while the other half will receive a control treatment. Both treatments include four therapeutic appointments. Changes in the severity of SAD will be measured after each appointment and on a 6-week follow-up assessment and will be compared between groups, with the change in SAD measured at baseline- and post-assessment as primary outcome. Discussion Self-guided digital therapeutic applications including ultra-short-time therapy combined with VR could help reduce the waiting time for patients and relieve the health system. The results of this study may inform psychotherapists regarding the potential of self-guided digital therapeutic applications including exposure-based behavioral experiments in VR for SAD and will provide important insight for future research on VR therapy

Excitatory stimulation of the ventromedial prefrontal cortex reduces cognitive gambling biases via improved feedback learning

Abstract Humans are subject to a variety of cognitive biases, such as the framing-effect or the gambler's fallacy, that lead to decisions unfitting of a purely rational agent. Previous studies have shown that the ventromedial prefrontal cortex (vmPFC) plays a key role in making rational decisions and that stronger vmPFC activity is associated with attenuated cognitive biases. Accordingly, dysfunctions of the vmPFC are associated with impulsive decisions and pathological gambling. By applying a gambling paradigm in a between-subjects design with 33 healthy adults, we demonstrate that vmPFC excitation via transcranial direct current stimulation (tDCS) reduces the framing-effect and the gambler's fallacy compared to sham stimulation. Corresponding magnetoencephalographic data suggest improved inhibition of maladaptive options after excitatory vmPFC-tDCS. Our analyses suggest that the underlying mechanism might be improved reinforcement learning, as effects only emerge over time. These findings encourage further investigations of whether excitatory vmPFC-tDCS has clinical utility in treating pathological gambling or other behavioral addictions