section_path: In culture/In studies on consciousness and philosophy
section_name: In studies on consciousness and philosophy
paragraph_text: In studies on consciousness and philosophy
  
  As an altered state of consciousness, dreamless deep sleep has been used as a way to investigate animal /human consciousness and qualia. Insights about differences of the living sleeping brain to its wakeful state and the transition period may have implications for potential explanations of human subjective experience, the so-called hard problem of consciousness, often delegated to the realm of philosophy, including neurophilosophy (or in some cases to religion and similar approaches).