Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, MI 48109, United States; Michigan Psychedelic Center, University of Michigan Medical School, Ann Arbor, MI 48109, United States; Chronic Pain and Fatigue Research Center, University of Michigan Medical School, Ann Arbor, MI 48109, United States; Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI 48109, United States. Electronic address: reharris@med.umich.edu.
2 papers in the library · 49 citations · publishing 2023-2025
Three different psychedelics—nitrous oxide, ketamine, and lysergic acid diethylamide—produce a common pattern of brain network changes despite having distinct molecular mechanisms and delivery methods. Each drug reduced connectivity within brain networks and enhanced connectivity between networks. Specifically, all three increased connections between the right temporoparietal junction and bilateral intraparietal sulcus, and between the precuneus and left intraparietal sulcus. These regions lie within the posterior cortical "hot zone," an area thought to mediate the qualitative aspects of experience. The findings identify a biologically plausible candidate for the subjective effects of both classical and non-classical psychedelics.
Shamanic journeying, an ancient spiritual practice, produces dynamic changes in heart function measurable through heart rate variability (HRV). In a single subject, drumming initiation decreased heart rate and increased HRV measures, while shapeshifting increased heart rate and certain HRV indicators. Qigong meditation also increased HRV measures, with greater changes in some metrics than drumming initiation. These findings suggest shamanic journeying involves widespread cardiac and physiological changes that can be tracked visually and via ultra-short-term HRV.