We exist in our own subjective minds that cannot be separated from our personal perspective, which make it impossible to reach real objectivity. The brain waves during dream sleep are not much different from those during awake. Dream sleep is dominated by the unconscious mind with the unaware feelings, thoughts, impulses, and desires. The rapid eye movement (REM) sleep is also called “paradoxical sleep”, the stage with dreams. Freud and Jung thought that dreams represent the unconscious mind. The meditation processes have similar features with the sleep cycles such as the brain wave patterns.
The sleep cycle has four stages, from drowsy and drifts to sleep, from random and fast brain waves to regular alpha brain waves. The slower theta brain waves then follow. In the next stage of deeper sleep, the EEGs show regular brain waves with sporadic burst of energy and brain activity. The third stage of sleep comes with the slow delta brain waves and lower body temperature. The fourth stage is the deepest level with delta waves, usually about one hour after the first stage.
Following this stage, the sleeper enters stage 1 or 2 and the rapid eye movement (REM) sleep, or dream sleep. At this time, faster, active, and random brain waves occur similar to the waking brain waves. Meanwhile, the blood pressure and heart rate arise, but the muscles are paralyzed temporarily. A brief awaken period may occur after the REM sleep, and the cycle begins once more.
Meditation is considered to have four cycles with deeper focus but without dreams, a state different from sleep or waking. EEG studies of Zen meditators showed mixed brain waves of alpha and theta similar to the light sleep pattern, a mix of sleeping and waking consciousness. Meditation may be a conscious way to discover our unconscious mind and learn more about ourselves.