Intensive breathing exercises can reduce blood flow to the brain by up to 45% and alter communication between brain networks, according to a new brain-imaging study. Participants reported experiences resembling some effects of psychedelic drugs, including altered perception, vivid mental imagery, a sense of unity and changes in self-experience. The researchers, presenting the work at the ECNP Congress in Munich, say changes in brain communication, rather than reduced blood flow alone, appear to be key to the altered state.
The study involved 30 healthy, experienced breathwork practitioners who performed high-ventilation breathwork during MRI scanning. Participants reported strong altered states of consciousness, describing a predominantly oceanic state – in other words, a deep feeling of connection to the universe — resembling that of a moderate to high dose of LSD or psilocybin, albeit with less pronounced visual effects. Brain imaging showed that global grey-matter cerebral blood flow fell by around 45% during the session, on average from 16.24 to 9.81 ml/100g/min. Those who reported stronger altered states also showed greater changes in the brain’s default mode network, which is involved in self-reflection and self-related thinking.
The researchers suggest that the intensity of the experience is not simply explained by reduced blood flow. Instead, the experience might track more closely with changes in communication within the default mode network, a brain system linked to self-reflection and self-related thought.
