EEG

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.

Katarzyna Janda et al. (2020) · Nutrients

This systematic review pooled nine randomised clinical trials to ask whether passionflower (Passiflora incarnata) helps with anxiety, sleep and related neuropsychiatric symptoms. Passionflower is a perennial climbing vine whose aerial parts, flowers and fruit are used medicinally, and whose activity is attributed to flavonoids such as apigenin and luteolin and to flavonoid glycosides including vitexin and isovitexin. The European Medicines Agency recognised it as a medicinal product in a 2014 herbal monograph. The review frames the problem as stress — the body's response to physical and psychological stressors, which becomes pathological when prolonged and can impair concentration and memory. The authors searched PubMed, Embase and ClinicalTrials.gov to October 2019 and screened 417 records down to nine trials run between 2017 and 2019, five of them in Iran. Participants were all adults, between 16 and 128 per trial, and eight of the nine trials enrolled healthy volunteers rather than diagnosed patients. Preparations varied widely — drops, tablets, syrup, a standardised extract and herbal tea — over periods from a single day to 30 days. Anxiety was measured with instruments including the State-Trait Anxiety Inventory and the Corah Dental Anxiety Scale, sedation with the Ramsey scale, and sleep with polysomnography. Most trials found reduced anxiety, though the benefit was smaller in people whose anxiety was mild to begin with. In generalised anxiety disorder, 45 drops daily for 28 days matched oxazepam without impairing work performance. Before surgery, 500 mg tablets lowered anxiety more than oxazepam, and a 700 mg per 5 mL syrup given 30 minutes before spinal anaesthesia reduced anxiety with haemodynamics unchanged. Compared with midazolam before wisdom-tooth extraction, 260 mg gave similar calming with markedly less somnolence (50% versus 82.5%) and no amnesia at all, against 20% on midazolam — although more participants would still choose midazolam again (52% versus 27.5%), which the authors attribute to that same amnesia preventing negative memories. Herbal tea drunk nightly for a week improved self-reported sleep quality by 5.2% over placebo. No adverse effects, memory loss or collapse of psychometric function were reported anywhere in the review. The practical reading is that passionflower performs comparably to two established sedatives for procedural anxiety, with a different side-effect profile — less somnolence, no amnesia — which may matter where alertness is wanted afterwards. The evidence is genuinely limited, though: nine small trials, too heterogeneous to pool statistically, three of them rated low quality, and most never recorded which part of the plant was used. Its anxiolytic action is thought to work through the GABA system. Larger trials across more varied populations are needed before firm dosing guidance is possible.

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.