Meditation-induced effects on whole-brain structural and effective connectivity

The Psychedelic Renaissance: A Catholic Perspective

After being outlawed in 1970, psychedelics have reemerged in the consciousness of Western society in the form of the so-called psychedelic renaissance. This has led to widespread interest in psychedelic compounds being used for recreation, treatment of mental illness and addiction, and even the so-called "enhancement" of individuals and society. This renewed interest in psychedelics has resulted in seemingly endless publications in both the popular and the academic press, including authors from fields as diverse as philosophy, theology, pharmacology, neuroscience, and clinical medicine. A common thread in this developing literature is the claim that psychedelic compounds mediate their reported benefits by inducing the so-called psychedelic mystical experience (PME). The nature of PME is hotly debated, with some claiming that it is entirely psychological and others proposing that it involves contact with extramental reality. This raises a number of important questions for Catholics, especially whether PME should be considered properly "mystical," how PME compares with traditionally understood Catholic mysticism, and whether, and if so under what conditions, psychedelics could be licitly used by the Catholic faithful. This paper is an attempt to begin the process of reconciling empiric scientific data regarding psychedelics generally, and PME specifically, with Catholic philosophical and theological considerations, with the goal of both providing recommendations regarding the licitness of the use of psychedelic compounds and inviting conversation about this important and challenging topic.

Summary

Over the past 20 years, there has been a renewed interest in of psychedelics. Many articles have been published extoling the benefits of psychedelics, including for the treatment of mental illness and addiction, recreation, and "enhancement" of individuals and society. A common claim is that the benefits of psychedelics are a result of the psychedelic mystical experience (PME). This paper considers both the use of psychedelics and PME from the perspective of Catholic theology, provides recommendations about their use for the Catholic faithful, and invites further conversation about this important and challenging topic.

Short Summary

This paper considers challenges posed by psychedelics, considers licitness of use, and calls for further discussion.

Inducing a meditative state by artificial perturbations: A mechanistic understanding of brain dynamics underlying meditation

Contemplative neuroscience has increasingly explored meditation using neuroimaging. However, the brain mechanisms underlying meditation remain elusive. Here, we implemented a mechanistic framework to explore the spatiotemporal dynamics of expert meditators during meditation and rest, and controls during rest. We first applied a model-free approach by defining a probabilistic metastable substate (PMS) space for each condition, consisting of different probabilities of occurrence from a repertoire of dynamic patterns. Moreover, we implemented a model-based approach by adjusting the PMS of each condition to a whole-brain model, which enabled us to explore in silico perturbations to transition from resting-state to meditation and vice versa. Consequently, we assessed the sensitivity of different brain areas regarding their perturbability and their mechanistic local-global effects. Overall, our work reveals distinct whole-brain dynamics in meditation compared to rest, and how transitions can be induced with localized artificial perturbations. It motivates future work regarding meditation as a practice in health and as a potential therapy for brain disorders.

Mind the Metabolic Gap: Bridging Migraine and Alzheimer's disease through Brain Insulin Resistance

Brain insulin resistance has recently been described as a metabolic abnormality of brain glucose homeostasis that has been proven to downregulate insulin receptors, both in astrocytes and neurons, triggering a reduction in glucose uptake and glycogen synthesis. This condition may generate a mismatch between brain's energy reserve and expenditure, ??mainly during high metabolic demand, which could be involved in the chronification of migraine and, in the long run, at least in certain subsets of patients, in the prodromic phase of Alzheimer's disease, along a putative metabolic physiopathological continuum. Indeed, the persistent disruption of glucose homeostasis and energy supply to neurons may eventually impair protein folding, an energy-requiring process, promoting pathological changes in Alzheimer's disease, such as amyloid-β deposition and tau hyperphosphorylation. Hopefully, the "neuroenergetic hypothesis" presented herein will provide further insight on there being a conceivable metabolic bridge between chronic migraine and Alzheimer's disease, elucidating novel potential targets for the prophylactic treatment of both diseases.

Neuroimaging evaluation of the long term impact of a novel paired meditation practice on brain function

Background

A growing number of advanced neuroimaging studies have compared brain structure and function in long term meditators to non-meditators. The goal is to determine if there may be long term effects on the brain from practicing meditation. In this paper, we present new data on the long term effects of a novel meditation practice in which the focus is on clitoral stimulation. The findings from such a study have implications for potential therapeutic uses with regard to various neurological or psychiatric conditions.

Methods

We evaluated the cerebral glucose metabolism in 40 subjects with an extended history (>1 year of practice, 2-3 times per week) performing the meditation practice called Orgasmic Meditation (OM) and compared their brains to a group of non-meditating healthy controls (N = 19). Both meditation and non-meditation subjects underwent brain PET after injection with 148 to 296 MBq of FDG using a standard imaging protocol. Resting FDG PET scans of the OM group were compared to the resting scans of healthy, non-meditating, controls using statistical parametric mapping.

Results

The OM group showed significant differences in metabolic activity at rest compared to the controls. Specifically, there was significantly lower metabolism in select areas of the frontal, temporal, and parietal lobes, as well as the anterior cingulate, insula, and thalamus, in the OM group compared to the controls. In addition, there were notable distinctions between the males and females with the females demonstrating significantly lower metabolism in the thalamus and insula.

Conclusions

Overall, these findings suggest that the long term meditation practitioners of OM have different patterns of resting brain metabolism. Since these areas of the brain in which OM practitioners differ from controls are involved in cognition, attention, and emotional regulation, such findings have implications for understanding how this meditation practice might affect practitioners over long periods of time.

The Missing Ingredient: How Misogyny and the Patriarchy Sabotage our Clinical Practice and Research

Discussing massive, unrelenting trauma, especially during a global pandemic, when the threat is not only personally affecting you, but also everyone else, is not an easy thing to do. We can see the consequences of two years of being locked inside. People's trauma responses literally came flooding out. It seems that the pandemic tipped us over an abyss that is hard to comprehend. In so many countries there are protests, laws rolling back basic human rights, the threat of fascism, and actual war. There seems to be widespread governmental corruption that cannot stop the favouritism of those who have wealth, and perpetually admonish those who do not. Our world seems very unstable. Change is deeply desired. Yet, this instability is predictable. It is predictable because the systems that created the structures that "run and rule" us are fundamentally destructive and violent. In never-ending ways, the only way that change happens is by utilizing violence as the only way to achieve change. This is the legacy of patriarchy. A system that not only is ruled by one group of people but also tends to be controlled by a very specific type of person. It is a system that cultivates human cruelty, selfishness, and violence. It is a system that is managed by those who do the "best" in violence. Most of us do not work this way but are forced to live this way because of the belief that humans are innately violent, selfish, and self-serving; a myth based on the traumatic reaction of fight. It is a dissociated, relational injury that is a direct result of not having our mothers and fathers able to be mothers and fathers. It is formed in misogyny. There are ways to heal, if one can comprehend what misogyny does to human beings, and what we would be like in its absence.

Long-Term and Meditation-Specific Modulations of Brain Connectivity Revealed Through Multivariate Pattern Analysis

Neuroimaging studies have provided evidence that extensive meditation practice modifies the functional and structural properties of the human brain, such as large-scale brain region interplay. However, it remains unclear how different meditation styles are involved in the modulation of these large-scale brain networks. Here, using machine learning and fMRI functional connectivity, we investigated how focused attention and open monitoring meditation styles impact large-scale brain networks. Specifically, we trained a classifier to predict the meditation style in two groups of subjects: expert Theravada Buddhist monks and novice meditators. We showed that the classifier was able to discriminate the meditation style only in the expert group. Additionally, by inspecting the trained classifier, we observed that the Anterior Salience and the Default Mode networks were relevant for the classification, in line with their theorized involvement in emotion and self-related regulation in meditation. Interestingly, results also highlighted the role of specific couplings between areas crucial for regulating attention and self-awareness as well as areas related to processing and integrating somatosensory information. Finally, we observed a larger involvement of left inter-hemispheric connections in the classification. In conclusion, our work supports the evidence that extensive meditation practice modulates large-scale brain networks, and that the different meditation styles differentially affect connections that subserve style-specific functions.

Unifying turbulent dynamics framework distinguishes different brain states

Significant advances have been made by identifying the levels of synchrony of the underlying dynamics of a given brain state. This research has demonstrated that non-conscious dynamics tend to be more synchronous than in conscious states, which are more asynchronous. Here we go beyond this dichotomy to demonstrate that different brain states are underpinned by dissociable spatiotemporal dynamics. We investigated human neuroimaging data from different brain states (resting state, meditation, deep sleep and disorders of consciousness after coma). The model-free approach was based on Kuramoto's turbulence framework using coupled oscillators. This was extended by a measure of the information cascade across spatial scales. Complementarily, the model-based approach used exhaustive in silico perturbations of whole-brain models fitted to these measures. This allowed studying of the information encoding capabilities in given brain states. Overall, this framework demonstrates that elements from turbulence theory provide excellent tools for describing and differentiating between brain states.