How yoga breathing practices affect brain function

This conclusion was reached by researchers from the Indian Institute of Technology in Gandhinagar together with the Sri Sri Institute of Advanced Studies and the cardiology centre Fortis Escort, writes Phys.org.

The authors of the paper documented that SCY practitioners have an increase in the amplitude of theta and delta rhythms of the brain, while the power of the alpha rhythm decreases. These changes are especially pronounced in phases of deep relaxation, such as yoga nidra, and correspond to the state of samadhi - complete inner peace - described in ancient texts.

Due to rising levels of stress, anxiety and depression, especially with limited access to psychotherapy, there is a growing interest in inexpensive and accessible ways of self-regulation. Yoga, breathing exercises and meditation have already been shown to be effective in improving emotional well-being, ability to concentrate and attention regulation.

In a new paper published in the journal npj Mental Health Research entitled "Discovering deep relaxation: the effect of rhythmic breathing on brain rhythms", scientists investigated how brain activity changes during different stages of SCY. The experiment involved 43 experienced practitioners taking classes at the Art of Living Foundation Centre in Bangalore. The participants were around 25 years old and had between one and 18 years of practice experience. A control group of 10 people simply listened to relaxing music during this time.

The study was conducted using a 24-channel EEG. The session was divided into five phases: preliminary rest, pranayama (breathing exercises), kriya (rhythmic breathing), yoga nidra (deep relaxation) and final rest. The greatest changes were recorded in the kriya and yoga-nidra phases: theta and delta waves increased, while alpha rhythm decreased, especially in the parietal and occipital areas of the brain.

A control group who listened to music did not show similar changes, suggesting that the effect was linked specifically to breathing technique. The researchers stress that regular practice of SCY can be an effective non-medicinal way to relieve stress and even form the basis of neurofeedback programmes.

However, the authors recognise the limitations of the study. For example, music was used as a control, whose parameters were not clearly described, and the group itself had no additional "silent" calibration. Also not included was a comparison with untrained participants who performed breathing exercises without a specific technique. In addition, two EEG channels were excluded from the analyses due to noise in some of the subjects, which may affect the interpretation of the data.

Finally, it is worth noting that one of the co-authors of the study represents the institute established by the founder of the SCI technique itself. This calls into question the full independence of the results, despite the official lack of conflict of interest.

Nevertheless, the study shows that rhythmic breathing is indeed capable of inducing physiological states comparable to deep meditation and deserves further scientific attention.