Associated with the deepest levels of sleep, delta waves are something of an enigma. First identified in the 1900s neurophysicist William Grey Walter, who was inspired by Hans Berger’s electroencephalograph, or EEG machine which enabled the study of the brain during sleep. Walter constructed his own version of this machine with additional capabilities and ended up detecting the various brain waves observed during sleep.
During the awake stage, small and fast beta waves are produced. As the brain slows down for sleep it produces alpha waves until eventually, once in deep sleep, the brain produces delta waves.
Delta waves operate at a frequency range of between 0-4Hz, which is super slow. It is during this stage that the brain is fully unconscious, which makes delta waves tricky to study as no one can remember what happens during this part of the sleep cycle.
So, what are their benefits?