Effects of moderate alcohol levels on default mode network connectivity in heavy drinkers

Background It is well established that even moderate levels of alcohol affect cognitive functions such as memory, self-related information processing, and response inhibition. Nevertheless, the neural mechanisms underlying these alcohol-induced changes are still unclear, especially on the network level. The default mode network (DMN) plays an important role in memory and self-initiated mental activities; hence, studying functional interactions of the DMN may provide new insights into the neural mechanisms underlying alcohol-related changes. Methods We investigated resting-state functional connectivity (rsFC) of the DMN in a cohort of 37 heavy drinkers at a breath alcohol concentration of 0.8 g/kg. Alcohol and saline were infused in a single-blind crossover design. Results Intranetwork connectivity analyses revealed that participants showed significantly decreased rsFC of the right hippocampus and right middle temporal gyrus during acute alcohol exposure. Moreover, follow-up analyses revealed that these rsFC decreases were more pronounced in participants who reported stronger craving for alcohol. Exploratory internetwork connectivity analyses of the DMN with other resting-state networks showed no significant alcohol-induced changes, but suffered from low statistical power. Conclusions Our results indicate that acute alcohol exposure affects rsFC within the DMN. Functionally, this finding may be associated with impairments in memory encoding and self-referential processes commonly observed during alcohol intoxication. Future resting-state functional magnetic resonance imaging studies might therefore also investigate memory function and test whether DMN-related connectivity changes are associated with alcohol-induced impairments or craving

Exposure to negative socio-emotional events induces sustained alteration of resting-state brain networks in older adults.

peer reviewedBasic emotional functions seem well preserved in older adults. However, their reactivity to and recovery from socially negative events remain poorly characterized. To address this, we designed a 'task-rest' paradigm in which 182 participants from two independent experiments underwent functional magnetic resonance imaging while exposed to socio-emotional videos. Experiment 1 (N = 55) validated the task in young and older participants and unveiled age-dependent effects on brain activity and connectivity that predominated in resting periods after (rather than during) negative social scenes. Crucially, emotional elicitation potentiated subsequent resting-state connectivity between default mode network and amygdala exclusively in older adults. Experiment 2 replicated these results in a large older adult cohort (N = 127) and additionally showed that emotion-driven changes in posterior default mode network-amygdala connectivity were associated with anxiety, rumination and negative thoughts. These findings uncover the neural dynamics of empathy-related functions in older adults and help understand its relationship to poor social stress recovery

Measuring Psychological Mechanisms in Meditation Practice: Using a Phenomenologically Grounded Classification System to Develop Theory-Based Composite Scores

peer reviewedObjectives: Deepening our understanding of the mechanisms by which meditation practices impact well-being and human flourishing is essential for advancing the science of meditation. A recent phenomenologically grounded classification system distinguishes attentional, constructive, and deconstructive forms of meditation based on the psychological mechanisms these practices primarily target or necessitate. Our main aim was to understand whether this theory-based taxonomy could be used as a guiding principle for combining established psychological self-report measures of meditation-related mechanisms into psychometrically adequate composite scores. Methods: We used cross-sectional data to compute meditation composite scores in three independent samples, namely meditation-naïve healthy older adults from the Age-Well trial (n = 135), meditation-naïve older adults with subjective cognitive decline from the SCD-Well trial (n = 147), and healthy long-term meditators (≥ 10,000 h of practice including one 3-year meditation retreat) from the Brain & Mindfulness project (n = 29). The psychometric properties of the composite scores were assessed via floor and ceiling effects, composite intercorrelations, interpretability, and convergent validity in relation to well-being, anxiety, and depression. Results: Three theoretically derived meditation composite scores, reflecting mechanisms involved in attentional, constructive, and deconstructive practices, displayed adequate psychometric properties. Separate secondary confirmatory factor analyses empirically corroborated the theoretically predicted three-factor structure of this classification system. Conclusions: Complementing data-driven approaches, this study offers preliminary support for using a theoretical model of meditation-related mechanisms to create empirically meaningful and psychometrically sound composite scores. We conclude by suggesting conceptual and methodological considerations for future research in this area.MEDIT-AGEING - Investigating the impact of meditation training on mental health and wellbeing in the ageing populationBRAINANDMINDFULNESS - Impact of Mental Training of Attention and Emotion Regulation on Brain and Behavior: Implications for Neuroplasticity, Well-Being and Mindfulness Psychotherapy Research

Визуализация сетей покоя (resting state) фМРТ у пациентов с тяжелой черепно-мозговой травмой

According to the literature, fMRI analysis at resting state (RS) is an informative methodological approach to the study of the basic level of a healthy and diseased brain’s functional activity. Averaging data over observation groups for various forms of cerebral pathology is often unacceptable. Previously, we mastered and applied the Independent Component Algorithm (ICA) in FSL software to visualize and analyze individual fMRI resting networks of healthy people.Objective: to analyze individual fMRI resting networks associated with the state of motor activity and consciousness in patients with severe traumatic brain injury (STBI).Materials and methods. Observation groups: 23 patients with SТBI (main) and 17 healthy volunteers (control). 3T fMRI recorded at rest. Individual (norm and STBI) and group (norm) analysis of RS networks was carried out by FSL software (ICA algorithm) and SPM8 in MATLAB.For the DMN and Sensorimotor networks, topography and total volume and intensity of their activation of their activation were determined.Results. The topography features reproduced in the group and individual analysis of fMRI of healthy people, as well as the averaged quantitative indicators of the rest networks were used as reference for pathology.In the context of motor activity, the RS Sensorimotor network was considered. Its topography is close to normal in most patients without or with mild hemiparesis. The growth of this defect is accompanied by a decrease in the integral quantitative indicators of the network, combined with asymmetric reduction (lack of activation in the contralateral motor cortex) in rough hemiparesis.In the context of consciousness, the expression and characteristics of the DMN network were compared in healthy people and in patients with STBI at its various levels: from clear to chronic vegetative state. It was revealed that a decrease in the level of consciousness is accompanied by a reduction in the cortical components of DMN, primarily the frontal (anterior DMN), not pronounced in the vegetative state. Activation of the caudal component of DMN (in particular, the posterior cingular cortex) persists in patients with depressed consciousness: distinct and even somewhat enhanced compared to the norm with its reversible form, less pronounced with chronicConclusion. The data obtained indicate the informative value of fMRI analysis of individual resting networks in the context of studying cerebral structural and functional foundations of consciousness and motor activity, as well as diagnosing the state of these functions in STBI.По данным литературы, анализ функциональной манитно-резонансной томографии (фМРТ) в состоянии покоя (RS) является информативным методическим подходом к исследованию базового уровня функциональной активности здорового и больного мозга. Усреднение данных по группам наблюдений при разных формах церебральной патологии зачастую неприемлемо. Ранее нами был освоен и применен алгоритм независимых компонент (ICA) в программном обеспечении FSL для визуализации и анализа индивидуальных сетей покоя фМРТ здоровых людей.Цель исследования: анализ индивидуальных сетей покоя фМРТ, сопряженных с состоянием двигательной активности и сознания, у пациентов с тяжелой черепно-мозговой травмой (ТЧМТ).Материал и методы. Группы наблюдений: 23 пациента с ТЧМТ, сопровождавшейся разной степенью угнетения сознания и двигательных нарушений в форме гемипареза (основная), и 17 здоровых испытуемых (контроль). У каждого записывали фМРТ 3 Тл в состоянии покоя с закрытыми глазами. Проводили групповой (в норме) и индивидуальный (в норме и при патологии) фМРТ-анализ RS с использованием программных средств FSL (алгоритм ICA) и SPM8 в среде MATLAB. Для сетей DMN и Sensorimotor определяли топографию активированных зон мозга, представленность сетей в группах наблюдений, общий объем и интенсивность их активации.Результаты. Воспроизводимые при групповом и индивидуальном анализе фМРТ здоровых людей особенности топографии, а также усредненные количественные показатели сетей покоя были использованы в качестве эталонных для патологии.В контексте двигательной активности рассматривали сенсомоторную сеть RS. Ее топография близка к норме у большинства пациентов без или с легким гемипарезом. Нарастание этого дефекта сопровождается  уменьшением интегральных количественных показателей сети, сочетающимся с асимметричной редукцией (отсутствием активации в контралатеральной моторной коре) при грубом гемипарезе.В контексте сознания анализировали особенности сети DMN у пациентов с ТЧМТ при разном его уровне: от ясного до хронического вегетативного состояния. Выявлено, что снижение уровня сознания сопровождается редукцией корковых составляющих DMN, в первую очередь лобных (anterior DMN), не выраженной при вегетативном состоянии. Активациия каудального компонента DMN (в частности, задней цингулярной коры) у пострадавших с угнетенным сознанием сохраняется: отчетливая и даже несколько усиленная по сравнению с нормой при обратимой его форме, менее выраженная – при хронической.Заключение. Полученные данные свидетельствуют об информативности фМРТ-анализа индивидуальных сетей покоя в контексте изучения церебральных структурно-функциональных основ сознания и двигательной активности, а также диагностики состояния этих функций при ТЧМТ

Exposure to negative socio-emotional events induces sustained alteration of resting-state brain networks in older adults

Basic emotional functions seem well preserved in older adults. However, their reactivity to and recovery from socially negative events remain poorly characterized. To address this, we designed a ‘task–rest’ paradigm in which 182 participants from two independent experiments underwent functional magnetic resonance imaging while exposed to socio-emotional videos. Experiment 1 (N = 55) validated the task in young and older participants and unveiled age-dependent effects on brain activity and connectivity that predominated in resting periods after (rather than during) negative social scenes. Crucially, emotional elicitation potentiated subsequent resting-state connectivity between default mode network and amygdala exclusively in older adults. Experiment 2 replicated these results in a large older adult cohort (N = 127) and additionally showed that emotion-driven changes in posterior default mode network–amygdala connectivity were associated with anxiety, rumination and negative thoughts. These findings uncover the neural dynamics of empathy-related functions in older adults and help understand its relationship to poor social stress recovery

Psycho-social factors associated with mental resilience in the Corona lockdown.

The SARS-CoV-2 pandemic is not only a threat to physical health but is also having severe impacts on mental health. Although increases in stress-related symptomatology and other adverse psycho-social outcomes, as well as their most important risk factors have been described, hardly anything is known about potential protective factors. Resilience refers to the maintenance of mental health despite adversity. To gain mechanistic insights about the relationship between described psycho-social resilience factors and resilience specifically in the current crisis, we assessed resilience factors, exposure to Corona crisis-specific and general stressors, as well as internalizing symptoms in a cross-sectional online survey conducted in 24 languages during the most intense phase of the lockdown in Europe (22 March to 19 April) in a convenience sample of N = 15,970 adults. Resilience, as an outcome, was conceptualized as good mental health despite stressor exposure and measured as the inverse residual between actual and predicted symptom total score. Preregistered hypotheses (osf.io/r6btn) were tested with multiple regression models and mediation analyses. Results confirmed our primary hypothesis that positive appraisal style (PAS) is positively associated with resilience (p < 0.0001). The resilience factor PAS also partly mediated the positive association between perceived social support and resilience, and its association with resilience was in turn partly mediated by the ability to easily recover from stress (both p < 0.0001). In comparison with other resilience factors, good stress response recovery and positive appraisal specifically of the consequences of the Corona crisis were the strongest factors. Preregistered exploratory subgroup analyses (osf.io/thka9) showed that all tested resilience factors generalize across major socio-demographic categories. This research identifies modifiable protective factors that can be targeted by public mental health efforts in this and in future pandemics

No evidence for the involvement of serotonin or the 5-HTTLPR genotype in intertemporal choice in a larger community sample

Background: Serotonin has been implicated in impulsive behaviours such as temporal discounting. While animal studies and theoretical approaches suggest that reduced tonic serotonin levels increase temporal discounting rates and vice versa, evidence from human studies is scarce and inconclusive. Furthermore, an important modulator of serotonin signalling, a genetic variation in the promoter region of the serotonin transporter gene (5-HTTLPR), has not been investigated for temporal discounting so far. Objective: First, the purpose of this study was to test for a significant association between 5-HTTLPR and temporal discounting. Second, we wished to investigate the effect of high/low tonic serotonin levels on intertemporal choice and blood oxygen-level-dependent response, controlling for 5-HTTLPR. Methods: We tested the association of 5-HTTLPR with temporal discounting rates using an intertemporal choice task in 611 individuals. We then manipulated tonic serotonin levels with acute tryptophan interventions (depletion, loading, balanced) in a subsample of 45 short (S)-allele and 45 long (L)/L-allele carriers in a randomised double-blind crossover design using functional magnetic resonance imaging and an intertemporal choice task. Results: Overall, we did not find any effect of serotonin and 5-HTTLPR on temporal discounting rates or the brain networks associated with valuation and cognitive control. Conclusion: Our findings indicate that serotonin may not be directly involved in choices including delays on longer timescales such as days, weeks or months. We speculate that serotonin plays a stronger role in dynamic intertemporal choice tasks where the delays are on a timescale of seconds and hence are therefore directly experienced during the experiment

Risk seeking for losses modulates the functional connectivity of the default mode and left frontoparietal networks in young males

Value-based decision making (VBDM) is a principle that states that humans and other species adapt their behavior according to the dynamic subjective values of the chosen or unchosen options. The neural bases of this process have been extensively investigated using task-based fMRI and lesion studies. However, the growing field of resting-state functional connectivity (RSFC) may shed light on the organization and function of brain connections across different decision-making domains. With this aim, we used independent component analysis to study the brain network dynamics in a large cohort of young males (N = 145) and the relationship of these dynamics with VBDM. Participants completed a battery of behavioral tests that evaluated delay aversion, risk seeking for losses, risk aversion for gains, and loss aversion, followed by an RSFC scan session. We identified a set of large-scale brain networks and conducted our analysis only on the default mode network (DMN) and networks comprising cognitive control, appetitive-driven, and reward-processing regions. Higher risk seeking for losses was associated with increased connectivity between medial temporal regions, frontal regions, and the DMN. Higher risk seeking for losses was also associated with increased coupling between the left frontoparietal network and occipital cortices. These associations illustrate the participation of brain regions involved in prospective thinking, affective decision making, and visual processing in participants who are greater risk-seekers, and they demonstrate the sensitivity of RSFC to detect brain connectivity differences associated with distinct VBDM parameters

Mental resilience in the Corona lockdown: First empirical insights from Europe

Background: The current Corona pandemic is not only a threat to physical health. First data from China and Europe indicate that symptoms of anxiety and depression and perceptions of stress rise significantly as a consequence of the pandemic. There are also anecdotal reports of increased domestic violence, divorce, and suicide rates. Hence, the Corona crisis is also a mental health crisis. There is urgent need for knowledge about factors that can protect mental health (resilience factors) in this world-wide crisis, which is different in nature from other crises that have so far been studied in resilience research. Methods: Potential resilience factors, exposure to Corona-specific and general stressors, as well as internalizing symptoms were assessed online in N=5000 adult Europeans. Resilience, as an outcome, was conceptualized as good mental health despite stressor exposure and measured as the inverse residual between actual and predicted symptom total score. Preregistered hypotheses (osf.io/r6btn) were tested with multiple regression models and mediation analyses. Results: Results confirmed our primary hypothesis that positive appraisal style (PAS) is positively associated with resilience(p<0.001). The resilience factor PAS also mediated the positive association between perceived social support (PSS) and resilience (p<0.001). In comparison with other resilience factors, positive appraisal specifically of the consequences of the Corona crisis was the single strongest factor. Conclusions: This research identifies modifiable protective factors that can be targeted by public mental health efforts. Future work will have to identify potential group differences in the effectiveness of these resilience factors, for improved prevention plannin