As a sleep expert with a background in neuroscience, I can tell you that delta wave sleep, also known as slow-wave sleep (SWS) or deep sleep, is a stage of sleep characterized by the presence of high-amplitude, low-frequency brain waves. These waves are the slowest of all brain wave frequencies and are associated with the deepest, most restorative phase of sleep. Delta waves have a frequency range of 0.5 to 4 Hz and are typically not visible in an awake state. They are most prominent during the third and fourth stages of non-rapid eye movement (NREM) sleep, which are collectively referred to as delta sleep. This stage of sleep is crucial for physical recovery, growth, and the consolidation of memories. During delta wave sleep, the body undergoes several important processes, including the release of growth hormone, tissue repair, and the strengthening of the immune system. It is also the stage where the brain processes and stores information from the day, converting short-term memories into long-term ones. In summary, delta wave sleep is a vital component of the sleep cycle that plays a significant role in the body's physical and mental restoration. read more >>

Delta waves, like other brain waves, are recorded with an electroencephalogram (EEG) and are usually associated with the deep stage 3 of NREM sleep, also known as slow-wave sleep (SWS), and aid in characterizing the depth of sleep.read more >>