A systematic review of 14 studies published between 2008 and 2018 found that yogic breathing techniques improve emotional and cognitive performance. The review followed PRISMA guidelines and included articles from Science Direct, PubMed, and Virtual Health Library. The authors note that the physiological mechanisms by which these practices modulate the human nervous system remain unclear and call for further research into specific aspects such as breath retention, prolonged expiration, attention on fluid respiration, and abdominal or thoracic breathing.
Religions have long recognized lucid dreaming (LD) as an important conscious state, predating modern scientific study by millennia. Hindu texts over 2,000 years old divide consciousness into waking, dreaming (including LD), and deep sleep. Tibetan Buddhists practice Dream Yoga to recognize dreams, overcome fears, and control dream content. Islam regards LD as a valuable mental state for mystical experiences. Christian theologian Augustine described LD as a preview of the afterlife. Spiritism in the nineteenth century linked LD to out-of-body experiences. Abrahamic religions view dreams as communication with God, while Indian traditions cultivate self-awareness through LD induction techniques. These historical religious insights can inform current scientific research on LD phenomenology.