Impaired action-safety learning and excessive relief during avoidance in patients with anxiety disorders.

Anxiety-related disorders are characterized by high levels of avoidance, but experimental research into avoidance learning in patients is scarce. To fill this gap, we compared healthy controls (HC, n = 47) with patients with obsessive-compulsive disorder (OCD, n = 33), panic disorder with agoraphobia (PDA, n = 40), and post-traumatic stress disorder (PTSD, n = 66) in a computer-based avoidance learning task, in order to examine (1) differences in rates of avoidance responses, (2) differences in action-safety learning during avoidance, and (3) differences in subjective relief following successful avoidance. The task comprised aversive negative pictures (unconditional stimulus, US) that followed pictures of two colored lamps (conditional stimuli, CS+), but not a third colored lamp (safety stimulus, CS-), and could be avoided by pressing a button during one CS+ (CS+ avoidable) but not the other (CS+ unavoidable). Participants rated their US-expectancy and level of relief on a trial-by-trial basis. Compared to the HC group, patient groups displayed higher levels of avoidance to the safety stimulus, and higher levels of US-expectancy and relief following the safety and avoidable danger stimulus. We propose that patients with anxiety disorders have low confidence in the safety consequences of avoidance actions, which induces increased relief during US omissions that reinforce the avoidance action.

The drive for thinness: Towards a mechanistic understanding of avoidance behaviors in a non-clinical population.

Fear of weight gain is a cardinal feature of eating disorders, including Anorexia Nervosa (AN). This fear motivates behaviors aimed at avoiding weight gain, such as restricting food intake. Of note, avoidance in AN is not confined to food-related items but extends to intense emotional states. Despite the presence of several forms of excessive avoidance in AN, little is known about the mechanisms underpinning avoidance behavior in AN. In the present exploratory study, we investigated whether university students with an elevated desire to avoid weight gain (as measured through self-reported Drive for Thinness, DT) show deficits in generic avoidance learning. Two-hundred and seventy-five female students filled in the Eating Disorder Inventory-II (EDI-II) and performed a food-unrelated avoidance task. Generalized and linear mixed models (GLMM) revealed that students scoring higher on the DT scale of the EDI-II showed more ineffective avoidance, suggesting a tendency for excessive avoidance in at-risk individuals for AN. Similar results might extend to other eating disorders.

A short-term musical training affects implicit emotion regulation only in behaviour but not in brain activity.

BACKGROUND: In everyday life, negative emotions can be implicitly regulated by positive stimuli, without any conscious cognitive engagement; however, the effects of such implicit regulation on mood and related neuro-mechanisms, remain poorly investigated in literature. Yet, improving implicit emotional regulation could reduce psychological burden and therefore be clinically relevant for treating psychiatric disorders with strong affective symptomatology. RESULTS: Music training reduced the negative emotional state elicited by negative odours. However, such change was not reflected at the brain level. CONCLUSIONS: In a context of affective rivalry a musical training enhances implicit regulatory processes. Our findings offer a first base for future studies on implicit emotion regulation in clinical populations.

The role of context in persistent avoidance and the predictive value of relief.

Fear renewal occurs when the context changes after fear extinction; however, whether avoidance is also influenced by context changes following fear extinction is untested. Forty-two participants performed an avoidance task within a typical fear renewal procedure. During Pavlovian conditioning, two stimuli (CS+) were associated with an aversive electrical stimulus (US), while a third stimulus was not (CS-). During subsequent avoidance learning, clicking a button canceled the delivery of the US during one but not the other CS+. Fear-related levels were then reduced by removing the US and the button in a new context (fear extinction with response prevention [Ext-RP]). Next, persistence of avoidance was tested in the extinction context B (group ABB) or the original conditioning context A (group ABA). We also tested whether ratings of relief pleasantness (based on both the CS- and the avoided CS+) during avoidance and Ext-RP predicted individual levels of persistent avoidance. Results showed that persistent avoidance was higher in conditioning context A than in extinction context B, and was predicted by higher relief pleasantness during avoidance conditioning. We conclude that persistent avoidance poses a threat to the long-term success of Ext-RP, and we propose that interventions aimed at mitigating the influence of context and relief levels might prove beneficial in this regard.

Stress matters: Randomized controlled trial on the effect of probiotics on neurocognition.

Probiotics are microorganisms that provide health benefits when consumed. In animals, probiotics reverse gut microbiome-related alterations in depression-like symptoms, in cognition, and in hormonal stress response. However, in humans, a causal understanding of the gut-brain link in emotion and cognition is lacking. Additionally, whether the effects of probiotics on neurocognition are visible only in presence of stress, remains unclear. We investigated the effects of a multispecies probiotic (Ecologic®Barrier) on specific neurocognitive measures of emotion reactivity, emotion regulation, and cognitive control using fMRI. Critically, we also tested whether probiotics can buffer against the detrimental effects of acute stress on working memory. In a double blind, randomized, placebo-controlled, between-subjects intervention study, 58 healthy participants were tested once before and once after a 28-day intervention. Without stress induction, probiotics did not affect brain, behavioral, or related self-report measures. However, relative to placebo, the probiotics group did show a significant stress-related increase in working memory performance after supplementation. This change was associated with intervention-related neural changes in frontal cortex during cognitive control exclusively in the probiotics group. Overall, our results show neurocognitive effects of a multispecies probiotic in healthy women only under challenging situations, buffering against the detrimental effects of stress on cognition.