Reductions in perceived stress following Transcendental Meditation practice are associated with increased brain regional connectivity at rest

Global Meditation Practices: A Literature Review

Research has shown that meditation is beneficial for chronic pain, stress, and many physical and mental conditions. The definition of meditation has many forms, is culturally influenced, and is practiced globally. This literature review seeks to report current literature on meditation related to therapeutic outcomes and create a globally informed definition of meditation for health-related purposes. From a western perspective, mindfulness-based stress relief (MBSR) is widely researched. Therefore, 15 studies from peer-reviewed research from 2015 and 2020 were used to examine various forms of meditation and describe a broader range of meditation practices other than MBSR. The different forms of meditation are: Acceptance and Commitment Therapy (Portugal), Active Engagement (Portugal), Adapted Mindfulness Program (Brazil), Adapted Mindfulness Program (Brazil), Cognitively-based Compassionate Training, Loving-kindness (United States, US), Mantra Meditation (US), Mindfulness-based stress reduction (US), Mindfulness-based cognitive therapy (South Korea), Osho (India), Psychoneuroendocrinoimmunology (Italy), Transcendental Meditation (Italy), Spiritual/Secular (US), Sufi (Pakistan), and Vipassana (Australia). The review was completed using a literature search method, and all meditation approaches report positive therapeutic outcomes for all participants (n = 768). This outcome enabled the creation of a broader therapeutic definition of meditation that can be applied in clinical practice.

Perceived stress modulates the activity between the amygdala and the cortex

The significant link between stress and psychiatric disorders has prompted research on stress's impact on the brain. Interestingly, previous studies on healthy subjects have demonstrated an association between perceived stress and amygdala volume, although the mechanisms by which perceived stress can affect brain function remain unknown. To better understand what this association entails at a functional level, herein, we explore the association of perceived stress, measured by the PSS10 questionnaire, with disseminated functional connectivity between brain areas. Using resting-state fMRI from 252 healthy subjects spanning a broad age range, we performed both a seed-based amygdala connectivity analysis (static connectivity, with spatial resolution but no temporal definition) and a whole-brain data-driven approach to detect altered patterns of phase interactions between brain areas (dynamic connectivity with spatiotemporal information). Results show that increased perceived stress is directly associated with increased amygdala connectivity with frontal cortical regions, which is driven by a reduced occurrence of an activity pattern where the signals in the amygdala and the hippocampus evolve in opposite directions with respect to the rest of the brain. Overall, these results not only reinforce the pathological effect of in-phase synchronicity between subcortical and cortical brain areas but also demonstrate the protective effect of counterbalanced (i.e., phase-shifted) activity between brain subsystems, which are otherwise missed with correlation-based functional connectivity analysis.

Sensory processing sensitivity and axonal microarchitecture: identifying brain structural characteristics for behavior

Previous research using functional MRI identified brain regions associated with sensory processing sensitivity (SPS), a proposed normal phenotype trait. To further validate SPS, to characterize it anatomically, and to test the usefulness in psychology of methodologies that assess axonal properties, the present study correlated SPS proxy questionnaire scores (adjusted for neuroticism) with diffusion tensor imaging (DTI) measures. Participants (n = 408) from the Human Connectome Project were studied. Voxelwise analysis showed that mean- and radial diffusivity correlated positively with SPS scores in the right and left subcallosal and anterior-ventral cingulum bundle, and the right forceps minor of the corpus callosum, all frontal cortex areas generally underlying emotion, motivation, and cognition. Further analyses showed correlations throughout medial frontal cortical regions in the right and left ventromedial prefrontal cortex, including the superior longitudinal fasciculus, inferior fronto-occipital fasciculus, uncinate, and arcuate fasciculus. Fractional anisotropy was negatively correlated with SPS scores in white matter (WM) of the right premotor/motor/somatosensory/supramarginal gyrus regions. Region of interest (ROI) analysis showed small effect sizes (- 0.165 to 0.148) in WM of the precuneus and inferior frontal gyrus. Other ROI effects were found in the dorsal-, ventral visual pathways and primary auditory cortex. The results reveal that in a large group of participants, axonal microarchitectural differences can be identified with SPS traits that are subtle and in the range of typical behavior. The results suggest that the heightened sensory processing in people who show that SPS may be influenced by the microstructure of WM in specific cortical regions. Although previous fMRI studies had identified most of these areas, the DTI results put a new focus on brain areas related to attention and cognitive flexibility, empathy, emotion, and first levels of sensory processing, as in primary auditory cortex. Psychological trait characterization may benefit from DTI methodology by identifying influential brain systems for traits.

Beyond the veil of duality-topographic reorganization model of meditation

Meditation can exert a profound impact on our mental life, with proficient practitioners often reporting an experience free of boundaries between a separate self and the environment, suggesting an explicit experience of "nondual awareness." What are the neural correlates of such experiences and how do they relate to the idea of nondual awareness itself? In order to unravel the effects that meditation has on the brain's spatial topography, we review functional magnetic resonance imaging brain findings from studies specific to an array of meditation types and meditator experience levels. We also review findings from studies that directly probe the interaction between meditation and the experience of the self. The main results are (i) decreased posterior default mode network (DMN) activity, (ii) increased central executive network (CEN) activity, (iii) decreased connectivity within posterior DMN as well as between posterior and anterior DMN, (iv) increased connectivity within the anterior DMN and CEN, and (v) significantly impacted connectivity between the DMN and CEN (likely a nonlinear phenomenon). Together, these suggest a profound organizational shift of the brain's spatial topography in advanced meditators-we therefore propose a topographic reorganization model of meditation (TRoM). One core component of the TRoM is that the topographic reorganization of DMN and CEN is related to a decrease in the mental-self-processing along with a synchronization with the more nondual layers of self-processing, notably interoceptive and exteroceptive-self-processing. This reorganization of the functionality of both brain and self-processing can result in the explicit experience of nondual awareness. In conclusion, this review provides insight into the profound neural effects of advanced meditation and proposes a result-driven unifying model (TRoM) aimed at identifying the inextricably tied objective (neural) and subjective (experiential) effects of meditation.

Online Yoga and Ayurveda Intervention as Tertiary Prevention of Psychological Comorbidities in COVID-19 Survivors: A Randomized Controlled Trial

Background and Purpose

About 56% of symptomatic COVID-19 survivors have been found with neuropsychological comorbidities, such as depression, anxiety, posttraumatic stress disorders (PTSD), and impaired quality of life (QoL). Alongside, antimicrobial, anti-inflammatory, neuroprotective, regenerative, immunomodulatory, cardio-pulmonary health promotive, and psychological benefits of yogic and Ayurvedic intervention are well documented. Therefore, this study aimed to assess the effect of online Yoga (OYI) and Yoga cum Ayurveda intervention (OYAI) on COVID-19-induced depression, anxiety, PTSD, and poor QoL.

Method

Seventy-two participants (males/females: 33/26) with at least a 3-month back history of symptomatic COVID-19 infection and age (mean ± SD: 32.33 ± 9.9 and 33.04 ± 12.9 for males and females, respectively) were recruited from Patanjali Ayurveda Hospital, Haridwar, India, and All India Institute of Medical Sciences, Rishikesh, Uttarakhand, India, before random allocation into an equal-sized control group (CG), Yoga group (YG) and Yoga cum concoction (YCG) group. Split-plot analysis of variance and Kruskal–Wallis tests with Bonferroni adjusted post hoc comparisons were computed for normal and nonnormal data using IBM SPSS (25th Version, SPSS South Asia Private Limited, Bangalore, India).

Results

Both the treatments—the 30-day OYI and OYAI, significantly improved depression ( P < .002, ES: -0.99 and P < .001, ES: -2.11), anxiety ( P < .001, ES: -1.32 and -1.89), PTSD ( P < .001, ES: -1.8 and -1.83) and QoL related constructs ( P < .001, ES: 0.63 and 0.76; 0.71 and 0.93 for each OYI and OYAI versus general health and physical health; P < .001, ES: 0.65 for OYAI versus psychological health; and P < .003, ES: 0.54 for OYI versus environment) of the participants compared to the controls.

Conclusion

OYAI may better ameliorate COVID-19-induced psychological comorbidities than OYI with no adverse effects.

The dynamic framework of mind wandering revisited: How mindful meta-awareness affects mental states' constraints

The dynamic framework of mind wandering (Christoff, Irving, Fox, Spreng, & Andrews-Hanna, 2016) is reviewed and modified through integrating the construct of mindful meta-awareness. The dynamic framework maintains that mind wandering belongs to a family of spontaneous thought phenomena. The key defining feature of mind wandering is 'spontaneity' which characterizes the dynamic nature of thoughts in the framework. The argument is made that incorporating the mindful meta-awareness construct modifies the dynamic framework as follows: (1) the framework's criteria for mind wandering do not hold anymore as meta-awareness changes the relationship between thoughts and constraints, and (2) lucid dreaming can be categorized as unguided thought while at the same time being dependent on deliberate constraints. Finally, the application of this modified framework will be discussed in terms of the treatment of mental disorders related to spontaneous thought alterations, in particular depression and nightmares.