Taoists speak about the ability to have Delta brain waves while awake. These brain waves are typically only present during deep sleep. However, through a long-term meditation habit, one can develop the ability to be deeply relaxed and wide awake. The chemicals in the brain that occur during sleep can occur during meditation and altered states of consciousness arise. Experiments have been conducted to show the possibility of awareness and relaxation occurring at the same time in a state known by the name ‘flow state’ in best-selling literature. Taoist masters see this as a return to our natural state.