Self regulation of brain areas underlying our emotional arousal.

Our body arousal is controlled by very ancient nerve centers deep inside our brains. I am quite clear that for myself and many others these areas have ramped up their activity in response to the political uncertainty surrounding us. I would like to understand and regulate this arousal in myself more effectively. Thus I have been fascinated by the article by Sabat et al. in the Feb. 3 issue of PNAS that uses uses natural language processing tools to define the 7 chief varieties of arousal, and then runs meta-analyses of the brain imaging literature to reveal that all varieties of arousal converge onto a cortical network composed of the presupplementary motor area and the left and right dorsal anterior insula.

This suggests that biofeedback or meditation techniques that reduce activity in these brain areas might be useful in allowing us to face adversity without unnecessary levels of arousal. In this vein, the same issue of PNAS has an article by Maher et al.   demonstrating the potential of using loving-kindness meditation (by novice meditators) to induce neural changes in beta and gamma activity in the amygdala and hippocampus - areas associated with emotional regulation and mood disorders.

Below, I pass on the abstracts of these two articles:

The Sabat  et al. article has the title "Evidence for domain-general arousal from semantic and neuroimaging meta-analyses reconciles opposing views on arousal" :

Significance

Arousal is a central concept linking brain and body, often put forward to explain motivated behavior. Although the term is widely used, its definition remains elusive, with diverging views in classical textbooks. Is arousal an abstraction of the mind reflecting a myriad of distinct biological processes, or is there some common neuronal feature? We used large-scale text mining methods and neuroimaging meta-analyses to reveal the existence of domain-general arousal, a cortical process shared by situations as different as a cognitive task, an emotional context, the transition to wakefulness or sexual behavior, involving notably a specific area of the anterior insula in humans. Our results pave the way for refined taxonomies of arousal, where concepts and neural data are well aligned.

Abstract

Arousal refers to changes in brain-body state underpinning motivated behavior but lacks a proper definition and taxonomy. Neuroscience and psychology textbooks offer surprisingly different views on what arousal is, from a global brain-wide modulation of neuronal activity to a multidimensional construct, with specific brain-body patterns tuned to a given situation. The huge number of scientific articles mentioning arousal (~50,000) highlights the importance of the concept but also explains why such a vast literature has never been systematically reviewed so far. Here, we leverage the tools of natural language processing to probe the nature of arousal in a data-driven, comprehensive manner. We show that arousal comes in seven varieties: cognitive, emotional, physiological, sexual, related to stress disorders, to sleep, or to sleep disorders. We then ask whether domain-general arousal exists at the cortical level, and run meta-analyses of the brain imaging literature to reveal that all varieties of arousal, except arousal in sleep disorders for lack of data, converge onto a cortical network composed of the presupplementary motor area and the left and right dorsal anterior insula. More precisely, we find that activity in dysgranular insular area 7 (Jülich atlas), the region with the highest convergence across varieties of arousal, is also specifically associated with arousal. The domain-general arousal network might trigger the reorganization of large-scale brain networks—a global mechanism—resulting in a context-specific configuration—in line with the multidimensional view. Future taxonomies of arousal refining the alignment between concepts and data should include domain-general arousal as a central component.

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The Maher et al. article has the title: "Intracranial substrates of meditation-induced neuromodulation in the amygdala and hippocampus" 

Significance

We leverage rare chronic, invasive electrophysiology recordings while participants engage in loving-kindness meditation to demonstrate that meditation induces neural changes in beta and gamma activity in the amygdala and hippocampus of novice meditators. These results build on previous findings in experienced meditators and reveal meditation’s potential for noninvasive neuromodulation of brain activity associated with emotional regulation and mood disorders.

Abstract

Meditation is an accessible mental practice associated with emotional regulation and well-being. Loving-kindness meditation (LKM), a specific subtype of meditative practice, involves focusing one’s attention on thoughts of well-being for oneself and others. Meditation has been proven to be beneficial in a variety of settings, including therapeutic applications, but the neural activity underlying meditative practices and their positive effects are not well understood. It has been difficult to understand the contribution of deep limbic structures given the difficulty of studying neural activity directly in the human brain. Here, we leverage a unique patient population, epilepsy patients chronically implanted with responsive neurostimulation devices that allow chronic, invasive electrophysiology recording to investigate the physiological correlates of LKM in the amygdala and hippocampus of novice meditators. We find that LKM-associated changes in physiological activity were specific to periodic, but not aperiodic, features of neural activity. LKM was associated with an increase in γ (30 to 55 Hz) power and an alternation in the duration of β (13 to 30 Hz) and γ oscillatory bursts in both the amygdala and hippocampus, two regions associated with mood disorders. These findings reveal the nature of LKM-induced modulation of limbic activity in first-time meditators.