Reducing Amygdala Activity and Phobic Fear through Cognitive Top-Down Regulation.

The amygdala is critically involved in emotional processing, including fear responses, and shows hyperactivity in anxiety disorders. Previous research in healthy participants has indicated that amygdala activity is down-regulated by cognitively demanding tasks that engage the PFC. It is unknown, however, if such an acute down-regulation of amygdala activity might correlate with reduced fear in anxious participants. In an fMRI study of 43 participants (11 men) with fear of snakes, we found reduced amygdala activity when visual stimuli were processed under high cognitive load, irrespective of whether the stimuli were of neutral or phobic content. Furthermore, dynamic causal modeling revealed that this general reduction in amygdala activity was partially mediated by a load-dependent increase in dorsolateral PFC activity. Importantly, high cognitive load also resulted in an acute decrease in perceived phobic fear while viewing the fearful stimuli. In conclusion, our data indicate that a cognitively demanding task results in a top-down regulation of amygdala activity and an acute reduction of fear in phobic participants. These findings may inspire the development of novel psychological intervention approaches aimed at reducing fear in anxiety disorders.

The Iranian Corona Stress Study: Psychological Impacts of COVID-19 Pandemic in an Iranian Population.

Background: To assess the psychological consequences of changes during the coronavirus 2019 (COVID-19) pandemic in the Iranian population. Methods: We performed an anonymous online survey in the first 3 weeks of March 2020. Individuals older than 14 who could read Persian, and lived in Iran, were eligible for the study. The participants had to rate their stress levels and depressive symptoms (using a nine-item Patient Health Questionnaire PHQ-9) during the last 2 weeks and before the pandemic retrospectively. The changes in the psychological measurements and their association with the sociodemographic factors and burdens due to confinement were assessed. Results: Overall, among the 3,210 subjects who participated in our study, both the stress levels and average depression scores increased. However, about 23% of the subjects reported a decrease in their stress levels. The burden of childcare, restrictions in private life, and thoughts about the future were positively correlated with the changes in the stress levels and depression scores (|r| > 0.15). However, feeling relieved in the pandemic condition, and enjoying more family time were associated with less change in the stress and depression scores. Being religious (odds ratio [OR] [CI]: 1.5 [1.3-1-8]) and older age (OR [CI]: 2.9 [1.8-4.6] for >55 years old) were identified as the resilience factors, whereas being a student (OR [CI]: 2.1 [1.6;2.7]), seeking a job (OR [CI]: 2.6 [1.8;3.9]), and history of a psychiatric disorder (OR [CI]: 3.2 [2.6;4]) were identified as the risk factors for depression. Conclusions: The stress levels and depressive symptoms have increased during the COVID-19 pandemic and this increase is related to different social and personal burdens due to the confinement conditions.

Cannabidiol enhances verbal episodic memory in healthy young participants: A randomized clinical trial.

Cannabis contains a multitude of different compounds. One of them, cannabidiol - a non-psychoactive substance - might counteract negative effects of Δ-9-Tetrahydrocannabinol on hippocampus-dependent memory impairment. The aim of the present study was to investigate the effect of vaping cannabidiol on verbal episodic memory in healthy young subjects. We used a double-blind, placebo-controlled, randomized crossover trial in 39 healthy young subjects. Participants received once a single dose of cannabidiol e-liquid (0.25 ml, 5% cannabidiol, 12.5 mg cannabidiol) and once placebo for vaping after learning 15 unrelated nouns. The primary outcome measure was the short delay verbal memory performance (number of correctly free recalled nouns) 20 min after learning. 34 participants (mean age: 22.26 [3.04]) completed all visits and entered analyses (17 received cannabidiol and 17 received placebo first). Cannabidiol enhanced verbal episodic memory performance (placebo: 7.03 [2.34]; cannabidiol 7.71 [2.48]; adjusted group difference 0.68, 95% CI 0.01 to 1.35; R2ß = .028, p = .048). Importantly, we did not detect medication effects on secondary outcome measures attention or working memory performance, suggesting that CBD has no negative impact on these basic cognitive functions. The results are in line with the idea that vaping cannabidiol interacts with the central endocannabinoid system and is capable to modulate memory processes, a phenomenon with possible therapeutic potential. Further studies are needed to investigate optimal dose-response and time-response relationships.

Effectiveness of a smartphone-based, augmented reality exposure app to reduce fear of spiders in real-life: A randomized controlled trial.

Although in vivo exposure therapy is highly effective in the treatment of specific phobias, only a minority of patients seeks therapy. Exposure to virtual objects has been shown to be better tolerated, equally efficacious, but the technology has not been made widely accessible yet. We developed an augmented reality (AR) application (app) to reduce fear of spiders and performed a randomized controlled trial comparing the effects of our app (six 30-min sessions at home over a two-week period) with no intervention. Primary outcome was subjective fear, measured by a Subjective Units of Distress Scale (SUDS) in a Behavioural Approach Test (BAT) in a real-life spider situation at six weeks follow-up. Between Oct 7, 2019, and Dec 6, 2019, 66 individuals were enrolled and randomized. The intervention led to significantly lower subjective fear in the BAT compared to the control group (intervention group, baseline: 7.12 [SD 2.03] follow-up: 5.03 [SD 2.19] vs. control group, baseline: 7.06 [SD 2.34], follow-up 6.24 [SD 2.21]; adjusted group difference -1.24, 95 % CI -2.17 to -0.31; Cohen's d = 0.57, p = 0.010). The repeated use of the AR app reduces subjective fear in a real-life spider situation, providing a low-threshold and low-cost treatment for fear of spiders.

Visual Exploration at Higher Fixation Frequency Increases Subsequent Memory Recall.

Only a small proportion of what we see can later be recalled. Up to date it is unknown how far differences in visual exploration during encoding affect the strength of episodic memories. Here, we identified individual gaze characteristics by analyzing eye tracking data in a picture encoding task performed by 967 healthy subjects during fMRI. We found a positive correlation between fixation frequency during visual exploration and subsequent free recall performance. Brain imaging results showed a positive correlation of fixation frequency with activations in regions related to vision and memory, including the medial temporal lobe. To investigate if higher fixation frequency is causally linked to better memory, we experimentally manipulated visual exploration patterns in an independent population of 64 subjects. Doubling the number of fixations within a given exploration time increased subsequent free recall performance by 19%. Our findings provide evidence for a causal relationship between fixation frequency and episodic memory for visual information.