Lower resting respiratory sinus arrhythmia (RSA), a measure of vagal tone, is linked to PTSD and OCD, and contemplative practices may increase RSA by activating the ventral vagal complex, aiding recovery. A systematic review of six studies (one cross-sectional, one pre-post, two cohort, two randomized controlled trials) found that mindfulness-related interventions increased parasympathetic activity and vagal tone while improving PTSD and OCD symptoms. Under polyvagal theory, mindfulness and compassion meditations act as neural exercises that expand the ventral vagal complex's capacity to regulate present states and build resilience.
Biophotons are ultra-weak visible light emissions from living organisms. This study applies four complementary analytical methods to photon emissions measured from the right palm of one human subject across three sessions, each with dark reference, pre-meditation rest, structured meditation (Sama Vritti box-breathing), and post-meditation recovery phases. The analyses converge on a systematic reduction of emission intermittency during meditation. Stripe-filtered Diffusion Entropy Analysis places emissions in a non-ergodic renewal regime with a decreased scaling exponent from pre-meditation to meditation. Renyi analysis shows reduced marginal amplitude burstiness and increased sequential pattern structure, interpreted as entrainment to the breathing rhythm. The authors propose this as a proof-of-concept framework for complexity analysis of human ultraweak photon emission under physiological modulation.
Concentrative meditation produces more numerous and marked changes in EEG power than analytical meditation, mainly increasing theta, alpha, and beta frequency ranges. Twenty-three Tibetan Buddhist monks and geshes from Sera-Jey Monastery in India participated in ecological EEG recordings within the monastery, performing analytical or concentrative meditation sessions at their best after a 5-minute baseline. The collaboration with the monastic community helped identify expert meditators and clarify differences between meditation types, addressing the limitation that heterogeneity of practices often hinders generalization of meditation research.