Category Archives: autonomic nervous system

New frontiers in heart rate variability and social coherence research

Article subtitled “Techniques, technologies, and implications for improving group dynamics and outcomes.” It’s part of this Frontiers in Science ebook. In the introductory chapter here’s what the ebook’s editors had to say about it:

“In closing, McCraty is a well-known person throughout the HRV community, having been a proponent of HRV Biofeedback for decades. His experience in the field can be traced to the very roots of awareness of the power and plain excitement of HRV engagement. Among his many areas of study and advocacy can be found the concept of ‘social coherence.’ These ideas springboard off simple group HRV Biofeedback infused with the basic scientific notions of social nervous system and its role in social engagement a la Porges’ polyvagal theory, past the newly emerging field of scientific study of interoception, and lands in the field of electromagnetic potentials in the evolutionary dynamics of ecosystems. Sound thinking prevails in the article’s central thesis that feedback of individual and group HRV will increase group cohesion, thereby promoting pro-social behaviors, such as kindness and cooperation among individuals, improved communication, and decreases in social discord and adversarial interactions. ‘Biomagnetic fields produced by the heart may be a primary mechanism in mediating HRV synchronization among group members’ he writes. Peripheral, implicit, and embedded in this message is the ‘Global Coherence Initiative’ (GCI). GCI takes social coherence to its farthest limits and into the frequency zone that is shared by solar-geomagnetic field synchronization and Schuman Resonances, where it has been noted that these resonant frequencies directly overlap with those of the human brain and cardiovascular system.”

Neuroscience on intentional breathing

From this piece:

“This recent study finally answers these questions by showing that volitionally controlling our respiration, even merely focusing on one’s breathing, yield additional access and synchrony between brain areas. This understanding may lead to greater control, focus, calmness, and emotional control.”

Sex differences in the gut-microbiome-brain axis


In recent years, the bidirectional communication between the gut microbiome and the brain has emerged as a factor that influences immunity, metabolism, neurodevelopment and behaviour. Cross-talk between the gut and brain begins early in life immediately following the transition from a sterile in utero environment to one that is exposed to a changing and complex microbial milieu over a lifetime. Once established, communication between the gut and brain integrates information from the autonomic and enteric nervous systems, neuroendocrine and neuroimmune signals, and peripheral immune and metabolic signals. Importantly, the composition and functional potential of the gut microbiome undergoes many transitions that parallel dynamic periods of brain development and maturation for which distinct sex differences have been identified. Here, we discuss the sexually dimorphic development, maturation and maintenance of the gut microbiome–brain axis, and the sex differences therein important in disease risk and resilience throughout the lifespan.