Salivary testosterone and cortisol response in acute stress modulated by seven sessions of mindfulness meditation in young males.

Stress is an established risk factor for negative health outcomes. Salivary cortisol and testosterone concentrations increase in response to acute psychosocial stress. It's crucial to reduce stress for health and well-being through evidence-based interventions. Body-mind interventions such as meditation and Tai Chi have shown reduced cortisol levels but mixed results in testosterone concentration after stress. To address this research gap, we conducted a pilot randomized controlled trial to examine the modulating effects of a short-term (seven 20-minute sessions) mindfulness meditation on testosterone and cortisol in response to acute stress. Using one form of mindfulness meditation - Integrative Body-Mind Training (IBMT) and an active control-relaxation training (RT), we assessed salivary cortisol and testosterone concentrations at three stages of stress intervention - rest, stress, and an additional 20-min IBMT or RT practice. We found increased cortisol and testosterone concentrations after acute stress in both groups, but testosterone rise was not associated with cortisol rise. Moreover, an additional practice immediately after stress produced higher testosterone concentrations in the IBMT group than the RT group, whereas cortisol concentration increased in the RT group than in the IBMT group at the same time point. These findings indicate that brief mindfulness intervention modulates a dual-hormone profile of testosterone and cortisol in response to acute stress presumably via the co-regulation of hypothalamus-pituitary-adrenal and hypothalamus-pituitary-testicular axes.

Gender differences in alcohol abuse/dependence among medical undergraduates during the post-COVID­19 pandemic period (October 20, 2020-April 5, 2021) in China.

BACKGROUND: This study aimed to assess the prevalence and the gender-specific risk factors of alcohol abuse/dependence among medical undergraduates during the post-COVID­19 pandemic period in China. METHOD: The Alcohol Use Disorders Identification Test-Consumption (AUDIT-C) was used to identify respondents with alcohol abuse/dependence. A questionnaire on basic demographics and mental distresses (learning burnout, depression symptoms, anxiety symptoms, excessive daytime sleepiness, and history of mental disorders) was used. The logistic regression model was used to explore the associations between the above characteristics and alcohol abuse/dependence. RESULTS: A total of 3,412 medical undergraduates were included in the analysis. Males showed a higher prevalence of alcohol abuse/dependence than females (16.6% vs 7.4%, p < 0.001). Alcohol abuse/dependence was associated with learning burnout (OR: 2.168, p < 0.001) and having a partner (OR: 1.788 p = 0.001) among female medical undergraduates. Among male medical undergraduates, excessive daytime sleepiness (OR: 1.788 p = 0.001) and older age (OR: 1.788, p = 0.001) were independently associated with alcohol abuse/dependence. CONCLUSION: Alcohol abuse/dependence was common among medical undergraduates during the post-COVID­19 pandemic period. Substantial gender differences in the prevalence and risk factors of alcohol abuse/dependence were found among medical undergraduates in this study, which highlighted the need for timely gender-specific screening and interventions. However, the cross-sectional design adopted in this study has limited the examination of causality, thus further longitudinal studies are warranted.

Default mode network mediates low-frequency fluctuations in brain activity and behavior during sustained attention.

The low-frequency (<0.1 Hz) fluctuation in sustained attention attracts enormous interest in cognitive neuroscience and clinical research since it always leads to cognitive and behavioral lapses. What is the source of the spontaneous fluctuation in sustained attention in neural activity, and how does the neural fluctuation relate to behavioral fluctuation? Here, we address these questions by collecting and analyzing two independent fMRI and behavior datasets. We show that the neural (fMRI) fluctuation in a key brain network, the default-mode network (DMN), mediate behavioral (reaction time) fluctuation during sustained attention. DMN shows the increased amplitude of fluctuation, which correlates with the behavioral fluctuation in a similar frequency range (0.01-0.1 Hz) but not in the lower (<0.01 Hz) or higher (>0.1 Hz) frequency range. This was observed during both auditory and visual sustained attention and was replicable across independent datasets. These results provide a novel insight into the neural source of attention-fluctuation and extend the former concept that DMN was deactivated in cognitive tasks. More generally, our findings highlight the temporal dynamic of the brain-behavior relationship.

Possible Role of Parvalbumin Interneurons in Meditation and Psychiatric Illness.

Parvalbumin (PV) interneurons are present in multiple brain regions and produce complex influences on brain functioning. An increasing number of research findings indicate that the function of these interneurons is more complex than solely to inhibit pyramidal neurons in the cortex. They generate feedback and feedforward inhibition of cortical neurons, and they are critically involved in the generation of neuronal network oscillation. These oscillations, generated by various brain regions, are linked to perceptions, thought processes, and cognitive functions, all of which, in turn, influence human emotions and behavior. Both animal and human studies consistently have found that meditation practice results in enhancement in the effects of alpha-, theta-, and gamma-frequency oscillations, which may correspond to positive changes in cognition, emotion, conscious awareness, and, subsequently, behavior. Although the study of meditation has moved into mainstream neuroscience research, the link between PV interneurons and any role they might play in meditative states remains elusive. This article is focused primarily on gamma-frequency oscillation, which is generated by PV interneurons, to develop insight and perspective into the role of PV interneurons in meditation. This article also points to new and emerging directions that address whether this role of PV interneurons in meditation extends to a beneficial, and potentially therapeutic, role in the treatment of common psychiatric disorders, including schizophrenia.

The acts of opening and closing the eyes are of importance for congenital blindness: Evidence from resting-state fMRI.

Volitional eye closure is observed only in conscious and awake humans, and is rare in animals. It is believed that eye closure can focus one's attention inward and facilitate activities such as meditation and mental imagery. Congenital blind individuals are also required to close their eyes for these activities. Resting-state functional magnetic resonance imaging (RS-fMRI) studies have found robust differences between the eyes-closed (EC) and eyes-open (EO) conditions in some brain regions in the sighted. This study analyzed data from 21 congenital blind individuals and 21 sighted controls by using amplitude of low-frequency fluctuation (ALFF) of RS-fMRI. The blind group and the sighted group shared similar pattern of differences between the EC and EO condition: ALFF was higher in the EC condition than the EO condition in the bilateral primary sensorimotor cortex, bilateral supplementary motor area, and inferior occipital cortex, while ALFF was lower in the EC condition than the EO condition in the medial prefrontal cortex, highlighting the "nature" effect on the difference between the EC and EO conditions. The results of other matrices such as fractional ALFF (fALFF) and regional homogeneity (ReHo) showed similar patterns to that of ALFF. Moreover, no significant difference was observed between the EC-EO pattern of the two subgroups of congenital blind (i.e., with and without light perception), suggesting that the EC-EO difference is irrespective of residual light perception which reinforced the "nature" effect. We also found between-group differences, i.e., more probably "nurture effect", in the posterior insula and fusiform. Our results suggest that the acts of closing and opening the eyes are of importance for the congenital blind, and that these actions and their differences might be inherent in the nature of humans.

The neuroscience of mindfulness meditation.

Research over the past two decades broadly supports the claim that mindfulness meditation - practiced widely for the reduction of stress and promotion of health - exerts beneficial effects on physical and mental health, and cognitive performance. Recent neuroimaging studies have begun to uncover the brain areas and networks that mediate these positive effects. However, the underlying neural mechanisms remain unclear, and it is apparent that more methodologically rigorous studies are required if we are to gain a full understanding of the neuronal and molecular bases of the changes in the brain that accompany mindfulness meditation.

Brief Mindfulness Meditation Induces Gray Matter Changes in a Brain Hub.

Previous studies suggest that the practice of long-term (months to years) mindfulness meditation induces structural plasticity in gray matter. However, it remains unknown whether short-term (<30 days) mindfulness meditation in novices could induce similar structural changes. Our previous randomized controlled trials (RCTs) identified white matter changes surrounding the anterior cingulate cortex (ACC) and the posterior cingulate cortex (PCC) within 2 to 4 weeks, following 5-10 h of mindfulness training. Furthermore, these changes were correlated with emotional states in healthy adults. The PCC is a key hub in the functional anatomy implicated in meditation and other perspectival processes. In this longitudinal study using a randomized design, we therefore examined the effect of a 10 h of mindfulness training, the Integrative Body-Mind Training (IBMT) on gray matter volume of the PCC compared to an active control-relaxation training (RT). We found that brief IBMT increased ventral PCC volume and that baseline temperamental trait-an index of individual differences was associated with a reduction in training-induced gray matter increases. Our findings indicate that brief mindfulness meditation induces gray matter plasticity, suggesting that structural changes in ventral PCC-a key hub associated with self-awareness, emotion, cognition, and aging-may have important implications for protecting against mood-related disorders and aging-related cognitive declines.

Effectiveness of a text-messaging-based smoking cessation intervention ("Happy Quit") for smoking cessation in China: A randomized controlled trial.

BACKGROUND: China has the highest global prevalence of cigarette smokers, accounting for more than 40% of the total cigarette consumption in the world. Considering the shortage of smoking cessation services in China, and the acceptability, feasibility, and efficacy of mobile-phone-based text messaging interventions for quitting smoking in other countries, we conducted a mobile-phone-based smoking cessation study in China. METHODS AND FINDINGS: We conducted a randomized controlled trial in China across 30 cities and provinces from August 17, 2016, to May 27, 2017. Adult smokers aged 18 years and older with the intention to quit smoking were recruited and randomized to a 12-week high-frequency messaging (HFM) or low-frequency messaging (LFM) intervention ("Happy Quit") or to a control group in a 5:2:3 ratio. The control group received only text messages unrelated to quitting. The primary outcome was biochemically verified continuous smoking abstinence at 24 weeks. Secondary outcomes included (1) self-reported 7-day point prevalence of abstinence (i.e., not even a puff of smoke, for the last 7 days) at 1, 4, 8, 12, 16, 20, and 24 weeks; (2) self-reported continuous abstinence at 4, 12, and 24 weeks; and (3) self-reported average number of cigarettes smoked per day. A total of 1,369 participants received 12 weeks of intervention or control text messages with continued follow-up for 12 weeks. The baseline characteristics of participants among the HFM (n = 674), LFM (n = 284), and control (n = 411) groups were similar. The study sample included 1,295 (94.6%) men; participants had a mean age of 38.1 (SD 9.79) years and smoked an average of 20.1 (SD 9.19) cigarettes per day. We included the participants in an intention-to-treat analysis. Biochemically verified continuous smoking abstinence at 24 weeks occurred in 44/674 participants in the HFM group (6.5%), 17/284 participants in the LFM group (6.0%), and 8/411 participants (1.9%) in the control group; participants in both the HFM (odds ratio [OR] = 3.51, 95% CI 1.64-7.55, p < 0.001) and the LFM (OR = 3.21, 95% CI 1.36-7.54], p = 0.002) intervention groups were more likely to quit smoking than those in the control group. However, there was no difference in quit rate between the HFM and LFM interventions. We also found that the 7-day point quit rate from week 1 to week 24 ranged from approximately 10% to more than 26% with the intervention and from less than 4% to nearly 12% without the intervention. Those who continued as smokers in the HFM group smoked 1 to 3 fewer cigarettes per day than those in the LFM group over the 24 weeks of trial. Among study limitations, the participants were able to use other smoking cessation services (although very few participants reported using them), cotinine tests can only detect smoking status for a few days, and the proportion of quitters was small. CONCLUSIONS: Our findings demonstrate that a mobile-phone-based text messaging intervention (Happy Quit), with either high- or low-frequency messaging, led to smoking cessation in the present study, albeit in a low proportion of smokers, and can therefore be considered for use in large-scale intervention efforts in China. Mobile-phone-based interventions could be paired with other smoking cessation services for treatment-seeking smokers in China. TRIAL REGISTRATION: ClinicalTrials.gov NCT02693626.

Brief meditation training induces smoking reduction.

More than 5 million deaths a year are attributable to tobacco smoking, but attempts to help people either quit or reduce their smoking often fail, perhaps in part because the intention to quit activates brain networks related to craving. We recruited participants interested in general stress reduction and randomly assigned them to meditation training or a relaxation training control. Among smokers, 2 wk of meditation training (5 h in total) produced a significant reduction in smoking of 60%; no reduction was found in the relaxation control. Resting-state brain scans showed increased activity for the meditation group in the anterior cingulate and prefrontal cortex, brain areas related to self-control. These results suggest that brief meditation training improves self-control capacity and reduces smoking.

Mechanisms of white matter changes induced by meditation.

Using diffusion tensor imaging, several recent studies have shown that training results in changes in white matter efficiency as measured by fractional anisotropy (FA). In our work, we found that a form of mindfulness meditation, integrative body-mind training (IBMT), improved FA in areas surrounding the anterior cingulate cortex after 4-wk training more than controls given relaxation training. Reductions in radial diffusivity (RD) have been interpreted as improved myelin but reductions in axial diffusivity (AD) involve other mechanisms, such as axonal density. We now report that after 4-wk training with IBMT, both RD and AD decrease accompanied by increased FA, indicating improved efficiency of white matter involves increased myelin as well as other axonal changes. However, 2-wk IBMT reduced AD, but not RD or FA, and improved moods. Our results demonstrate the time-course of white matter neuroplasticity in short-term meditation. This dynamic pattern of white matter change involving the anterior cingulate cortex, a part of the brain network related to self-regulation, could provide a means for intervention to improve or prevent mental disorders.

Improving creativity performance by short-term meditation.

BACKGROUND: One form of meditation intervention, the integrative body-mind training (IBMT) has been shown to improve attention, reduce stress and change self-reports of mood. In this paper we examine whether short-term IBMT can improve performance related to creativity and determine the role that mood may play in such improvement. METHODS: Forty Chinese undergraduates were randomly assigned to short-term IBMT group or a relaxation training (RT) control group. Mood and creativity performance were assessed by the Positive and Negative Affect Schedule (PANAS) and Torrance Tests of Creative Thinking (TTCT) questionnaire respectively. RESULTS: As predicted, the results indicated that short-term (30 min per day for 7 days) IBMT improved creativity performance on the divergent thinking task, and yielded better emotional regulation than RT. In addition, cross-lagged analysis indicated that both positive and negative affect may influence creativity in IBMT group (not RT group). CONCLUSIONS: Our results suggested that emotion-related creativity-promoting mechanism may be attributed to short-term meditation.

Short-term meditation induces changes in brain resting EEG theta networks.

Many studies have reported meditation training has beneficial effects on brain structure and function. However, very little is known about meditation-induced changes in brain complex networks. We used network analysis of electroencephalography theta activity data at rest before and after 1-week of integrative body-mind training (IBMT) and relaxation training. The results demonstrated the IBMT group (but not the relaxation group) exhibited significantly smaller average path length and larger clustering coefficient of the entire network and two midline electrode nodes (Fz and Pz) after training, indicating enhanced capacity of local specialization and global information integration in the brain. The findings provide the evidence for meditation-induced network plasticity and suggest that IBMT might be helpful for alterations in brain networks.

Meditation experience is associated with differences in default mode network activity and connectivity.

Many philosophical and contemplative traditions teach that "living in the moment" increases happiness. However, the default mode of humans appears to be that of mind-wandering, which correlates with unhappiness, and with activation in a network of brain areas associated with self-referential processing. We investigated brain activity in experienced meditators and matched meditation-naive controls as they performed several different meditations (Concentration, Loving-Kindness, Choiceless Awareness). We found that the main nodes of the default-mode network (medial prefrontal and posterior cingulate cortices) were relatively deactivated in experienced meditators across all meditation types. Furthermore, functional connectivity analysis revealed stronger coupling in experienced meditators between the posterior cingulate, dorsal anterior cingulate, and dorsolateral prefrontal cortices (regions previously implicated in self-monitoring and cognitive control), both at baseline and during meditation. Our findings demonstrate differences in the default-mode network that are consistent with decreased mind-wandering. As such, these provide a unique understanding of possible neural mechanisms of meditation.

Short term integrative meditation improves resting alpha activity and stroop performance.

Our previous research showed that short term meditation training reduces the time to resolve conflict in the flanker task. Studies also show that resting alpha increases with long term meditation practice. The aim of this study is to determine whether short term meditation training both increases resting alpha activity and reduces the time to resolve conflict in the Stroop task and whether these two effects are related. Forty-three Chinese undergraduates were randomly assigned an experiment group given 5 days meditation training using integrative body-mind training (IBMT) and a relaxation training control. After training, only the IBMT group showed decreased conflict reaction time (RT), and increased resting mean alpha power. Moreover, the higher the enhancement of resting alpha power, the stronger the improvement of conflict RT. The results indicate that short term meditation diffusely enhances alpha and improves the ability to deal with conflict and moreover these two effects are positively related.

Digital mindfulness training and cognitive functions: A preregistered systematic review of neuropsychological findings.

Traditional mindfulness interventions have been frequently reported to be effective in improving cognitive functions. In recent years, however, traditional programs are being increasingly replaced by technology-enabled mindfulness training programs. The aim of the present systematic review (PROSPERO ID: CRD42021289480) is to evaluate the research evidence on their effects on cognitive functions. Empirical training studies in the realm of digital mindfulness training that fulfilled the inclusion criteria led to 19 studies and 1654 participants being included in this review from among the papers searched in PubMed, Scopus, and Web of Knowledge. Results support previous assumptions on the potential of digital mindfulness training, with the most robust effect on attention control, followed by executive regulation, memory, cognitive flexibility, and other cognitive functions. However, the number of studies that did not find significant changes at least equaled, if not exceeded, the number of studies that found increases. The heterogeneity of identified studies prompted us to discuss several aspects in order to help the future development of digital applications.

Personal and impersonal stimuli differentially engage brain networks during moral reasoning.

Moral decision making has recently attracted considerable attention as a core feature of all human endeavors. Previous functional magnetic resonance imaging studies about moral judgment have identified brain areas associated with cognitive or emotional engagement. Here, we applied graph theory-based network analysis of event-related potentials during moral decision making to reveal the personal/impersonal distinction in the organization of functional connectivity. Our results indicated that the personal task had more larger long-range connections involved in frontal regions and the right hemisphere, and higher network efficiency of some frontal electrodes such as F2 than the impersonal. These might be related to brain resource reorganization contributing to efficient conflict resolution. These findings provide new insights into neural mechanisms of moral dilemmas.

Short-term meditation induces white matter changes in the anterior cingulate.

The anterior cingulate cortex (ACC) is part of a network implicated in the development of self-regulation and whose connectivity changes dramatically in development. In previous studies we showed that 3 h of mental training, based on traditional Chinese medicine (integrative body-mind training, IBMT), increases ACC activity and improves self-regulation. However, it is not known whether changes in white matter connectivity can result from small amounts of mental training. We here report that 11 h of IBMT increases fractional anisotropy (FA), an index indicating the integrity and efficiency of white matter in the corona radiata, an important white-matter tract connecting the ACC to other structures. Thus IBMT could provide a means for improving self-regulation and perhaps reducing or preventing various mental disorders.

Promoting Healthy Aging: Insights on Brain and Physiological Health - A Special Issue.

This special issue focuses on healthy aging and neuroprotection, particularly in the context of brain and physiological health during normal aging and Alzheimer's disease. It highlights the importance of physical activity, nutrition, and stress management in promoting healthy aging and preventing neurodegenerative diseases. The issue explores molecular pathways, genetic factors, and lifestyle interventions that support brain and physiological health in aging populations. Overall, the findings presented in this special issue underscore the importance of healthy lifestyles in promoting brain and physiological health during the aging process.

The thalamic clustering coefficient moderates the vigor-sleep quality relationship.

Sleep disorders affect more than one-quarter of the world's population, resulting in reduced daytime productivity, impaired immune function, and an increased risk of cardiovascular disease. It is important to identify the physiological and psychological factors related to sleep for the prevention and treatment of sleep disorders. In this study, we correlated measurements of emotional state, sleep quality, and some brain neural activity parameters to better understand the brain and psychological factors related to sleep. Resting-state functional magnetic resonance imaging (rs-fMRI) of 116 healthy undergraduates were analyzed using graph theory to assess regional topological characteristics. Among these, the left thalamic cluster coefficient proved to be the ablest to reflect the characteristics of the sleep neural graph index. The Profile of Mood States (POMS) was used to measure vigor, and the Pittsburgh Sleep Quality Index (PSQI) to assess sleep quality. The results showed that the left thalamic clustering coefficient was negatively correlated with sleep quality and vigor. Further, the left thalamic clustering coefficient moderated the relationship between vigor and sleep quality. When the left thalamic clustering coefficient was very low, there was a significant positive correlation between vigor and sleep quality. However, when the left thalamic clustering coefficient was high, the correlation between vigor and sleep quality became insignificant. The relationship between vigor and sleep quality is heterogeneous. Analyzing the function of the left thalamic neural network could help understand the variation in the relationship between vigor and sleep quality in different populations. Such observations may help in the development of personalized interventions for sleep disorders.