HRV Monitor

Waqar Husain et al. (2026) · Brain and behavior

This systematic review of 105 studies examined how religious and spiritual practices -- meditation, prayer, chanting, ritual, and mystical experience -- show up in brain scans. It pooled evidence across eight traditions (Buddhism, Christianity, Islam, Hinduism, Santo Daime, Spiritism, Sant Mat, and mixed traditions) and seven brain-imaging methods, filling a gap left by earlier reviews that each covered only one practice or one faith. Neurotheology, the scientific study of how spiritual experience relates to brain function, asks whether these ancient practices leave a measurable, functional signature on the nervous system. Researchers searched three major databases from their earliest records through mid-2026 and found 450 candidate studies; after removing duplicates and screening for eligibility, 105 studies remained. Each had to study real human participants using an objective brain-measurement tool -- functional or structural MRI, EEG, MEG, PET, SPECT, or similar -- during an actual religious, spiritual, or contemplative practice, not passive exposure to religious words or images. Because the studies varied enormously in tradition, practice, and method, the team combined findings narratively rather than statistically averaging them. Meditation studies (the largest group, 35 studies) consistently found quieter activity in the brain's default mode network, the circuit active during mind-wandering and self-focused thought, alongside more efficient attention-related brain activity in long-term practitioners. Prayer (21 studies) activated brain regions used for understanding other people's minds when prayer was personal and improvised, suggesting the brain treats sincere prayer like a real conversation, and activated reward circuitry during peak spiritual feelings among some worshippers. Chanting and recitation (25 studies) calmed emotional brain circuits -- OM chanting, for example, reduced activity along the same pathway targeted by an approved medical nerve-stimulation therapy. Mental-health-relevant findings (14 studies) included a randomized trial in which loving-kindness meditation eased depression symptoms in diagnosed patients, and a mindfulness program that lowered stress-hormone levels months later. Eleven studies of unusual states -- near-death imagery, ayahuasca ceremonies, and trance -- showed the most widespread brain-network changes of any practice type. The review's authors state plainly that religious and spiritual practices are neurologically real, measurable behaviors, not just subjective reports, and that the brain circuits they engage overlap with those disrupted in depression, anxiety, and addiction. They stop short of claiming these practices treat any diagnosed condition, since most studies involved healthy volunteers rather than patients. The search covered only English-language, peer-reviewed studies, and the wide variety of traditions and methods meant the team could describe patterns but not calculate a single combined effect size.

Hui Ruan et al. (2023) · Journal of integrative and complementary medicine

This randomized trial with 45 children explored whether a traditional Thai massage technique, taught to parents and delivered at home, could help regulate the nervous system and improve walking in kids with autism spectrum disorder (ASD). Many children with ASD have an autonomic nervous system — the part of the body that controls automatic functions like heart rate — that runs a bit "on edge," and some also have subtle walking differences linked to how their brain plans movement. Forty-eight children ages 7-12 at a school in China were randomly assigned to either 8 weeks of Traditional Thai Massage, given by their own parents twice a week for 50 minutes after the parents were personally trained and certified, or to their normal school routine. Researchers used a fingertip sensor to measure heart rate variability (a sign of nervous system balance) and a wearable motion sensor to analyze each child's walking pattern, checking in right after the 8 weeks and again two months later. Children who received the massage showed clear signs of a calmer, better-balanced nervous system compared to the control group — measurements linked to the body's natural "rest and relax" response improved significantly, and this held up even two months after the massage program ended. Their walking also changed in one specific way: their stride length (how far each step covers) got noticeably longer, an improvement that also lasted through the two-month check-in. Other walking measures, like speed and step timing, didn't change significantly. These results suggest that a relatively simple, parent-led massage technique — no expensive equipment or professional therapist required — may help calm the nervous system and improve certain aspects of walking in children with autism, with some benefits lasting months later. Because there was no "pretend massage" comparison group, it's hard to know how much of the effect came from the specific Thai massage technique versus simply the comforting touch and extra parent attention involved. The study also included very few girls, reflecting how autism is diagnosed more often in boys, so it's unclear if the results apply equally to girls. Larger and longer studies would help confirm these promising early findings.

Aibo Li et al. (2025) · Frontiers in public health

This study tested whether spending three days in a forest could help lower blood pressure in older adults who already have essential hypertension (high blood pressure with no single identifiable cause). Thirty-six adults aged 60 to 80 with diagnosed hypertension took part: 24 went to a subtropical forest national park in China for a 3-day retreat, while 12 stayed in the city of Hangzhou following the same daily schedule, so researchers could compare the two settings directly. The forest group took part in daily gentle activities designed to immerse them in nature: eight trigrams boxing (a slow, breath-focused Qigong practice), a few hours of guided forest walking, a traditional tea ceremony, and a meditation session. Both groups ate the same meals and kept the same schedule. Before and after the trip, researchers measured blood pressure, heart rate, blood oxygen, heart-rate variability (a marker of nervous-system balance), several inflammation and stress-hormone markers in the blood, and mood using a standard questionnaire. After the trip, the forest group's blood pressure was significantly lower than the city group's, both the top number (systolic, ~134 vs. 147) and bottom number (diastolic, ~78 vs. 85). Inflammation, measured by a sensitive CRP blood test, was also significantly lower in the forest group. Heart-rate variability shifted in a pattern the researchers interpreted as a healthy autonomic-nervous-system adjustment for this population. On mood, the forest group reported significantly less tension and anxiety and significantly more energy and vitality than the city group; other mood measures trended better but weren't statistically significant. Heart rate, blood oxygen, and most other blood markers (IL-6, cortisol, oxidative-stress markers) didn't differ significantly between the groups. These results suggest a short forest retreat combining gentle nature-based activities may meaningfully help lower blood pressure, ease inflammation, and improve mood in older adults with hypertension, as a complement to standard care. Because the forest program bundled several practices together (forest walking, qigong, meditation, tea ceremony) and compared a larger forest group to a much smaller city group in a different location, it's hard to know how much came from the forest setting itself versus the other activities. The trial only lasted three days, so it can't say whether the benefits last, and larger, longer studies are needed before forest bathing becomes a standard recommendation for hypertension.

David Muehsam et al. (2015) · Global advances in health and medicine

The study provides an overview of biofield devices, which are instruments designed to measure or manipulate biofield interactions that influence biological functions and health outcomes. The significance of this research lies in its potential to enhance understanding of the interconnectedness of biological processes and psychosocial factors, thereby advancing clinical applications in health and wellness. The objective is to review existing biofield devices, particularly those supported by peer-reviewed evidence, to identify promising modalities for further investigation. The study emphasizes the need for interdisciplinary research to validate the efficacy and mechanisms of these devices. The methods employed in this study include a comprehensive review of existing biofield devices, focusing on those with peer-reviewed support. The review does not specify a sample size or participant characteristics, as it synthesizes findings from various studies rather than conducting original research. The intervention involves examining the operational mechanisms of different biofield devices and their therapeutic and diagnostic applications. Outcomes are measured through a qualitative assessment of the devices' mechanisms and their clinical implications, with an emphasis on the need for robust experimental protocols. The study highlights the importance of addressing methodological challenges in biofield research. The findings indicate that a variety of biofield devices exist, some with well-understood mechanisms and clinical applications, while others remain poorly understood. The authors interpret these findings as indicative of a biophysical basis for biofield coordination, suggesting that these devices can influence biological processes through subtle signaling. There are potential clinical implications, including the provision of low-cost, personalized diagnostic and therapeutic options. However, the study acknowledges significant limitations, such as the complexity of biofield interactions and the current lack of understanding regarding the mechanisms behind these modalities. Non-significant findings include the absence of specific statistical data, as the review synthesizes qualitative insights rather than quantitative results. In conclusion, biofield devices represent a significant advancement in biofield science, highlighting the need for further research and interdisciplinary collaboration. The development of these devices could lead to more personalized and humane medical practices, enhancing our understanding of interconnectedness within various biological systems. Future research should focus on systematic studies of biofield interactions and their implications for science and medicine. The study emphasizes the necessity for comprehensive investigations and sufficient funding to explore the potential of biofield devices effectively.