Breathing is a constant experience, which we practically don’t notice. Yet, with the right precautions, breathing can have a profound impact on our body. Relax, but also get high to the point of altering our state of consciousness, a bit like psychedelic substances such as LSD or psilocybin (the active ingredient of hallucinogenic mushrooms) would do. This was confirmed by researchers from the University of Heidelberg, in a study published in Progress in Neuropsychopharmacology and Biological Psychiatry who investigated the effects of voluntary hyperventilation on the functioning of the human brain, obtaining an accurate mapping of the physiological dynamics that accompany the alteration of consciousness produced by these practices.
Breath control
Conscious breathing techniques (breathwork in English) have been part of the ascetic and meditative practices of many cultures for millennia. They have recently also attracted the interest of science, as a non-pharmacological alternative to influence the state of consciousness, and obtain effects such as relaxation, sedation, and the general improvement of psychological well-being (with practices such as transcendental meditation, in which breathing control plays a leading role).
Some forms of conscious breathing, such as controlled hyperventilation techniques or continuous breathing (in which exhalation and inhalation follow one another without pauses) are known to produce alterations in consciousness, perception and mood, which are very similar to those induced by actual narcotic substances. Knowledge in this regard, however, remained anecdotal until today: there was a lack of rigorous clinical data collected in a controlled environment to quantify the neurophysiological effects of these techniques on healthy subjects. And that’s what the authors of the research decided to achieve.
The study
The research involved 30 healthy young adults who had already experienced conscious hyperventilation techniques. Participants underwent structured sessions of high-intensity breathwork and cycles of controlled hyperventilation guided by expert instructors. During the sessions, the researchers monitored the participants’ vital signs and electroencephalographic activity, and evaluated their subjective experiences using standardized psychometric scales for assessing altered states of consciousness.
Analysis of the brain tracings highlighted significant reductions in blood flow to the gray matter, accompanied by an increase in heart and respiratory rates. “The 45 percent reduction in blood flow to the gray matter represents a substantial hemodynamic perturbation for a voluntary, nonpharmacological intervention,” the study authors write. “Although the reduction remains below the critical threshold of 50-60 percent beyond which cerebral oxygenation becomes insufficient, it is very close to, and is higher than, what is typically observed in clinical hyperventilation interventions.”
Promising therapies
On a perceptual level, the data collected reveal that a high percentage of participants experienced significant alterations in their state of consciousness, described as sensations of extreme lightness, detachment from bodily reality, mild synesthesia (the overlap of different sensory experiences) and a profound alteration of temporal perception. Unlike chemical induction, however, breathwork allows immediate control: interrupting the technique or returning to a regular breathing rhythm quickly eliminates side effects and returns the subject to full cognitive control in a few minutes.
“These are results that have important implications for understanding the neurobiology of non-pharmacological altered states of consciousness – conclude the authors of the study – and which could help to develop therapeutic interventions based on the conscious control of breathing”.