Brain activity varies depending on the state of consciousness, such as wakefulness, sleep, or meditation. Different types of brain waves reflect different levels of arousal and cognitive functions.

Some of the main types of brain waves are:

• Gamma waves: These are the fastest and highest frequency brain waves, ranging from 30 Hz to 50 Hz or more. They occur when the brain is intensely focused, engaged, or solving a problem².
• Beta waves: These are the most common brain waves during wakefulness, especially when the eyes are open. They range from 12 Hz to 30 Hz and are associated with alertness, attention, and cognitive tasks²⁴.
• Alpha waves: These are slower and lower frequency brain waves than beta waves, ranging from 8 Hz to 12 Hz. They occur when the brain is relaxed, such as with the eyes closed or during meditation. They also mark the transition from wakefulness to sleep¹⁴.
• Theta waves: These are even slower and lower frequency brain waves than alpha waves, ranging from 4 Hz to 8 Hz. They occur during the early stages of sleep, as well as during drowsiness and deep meditation. They are important for memory and learning²³.
• Delta waves: These are the slowest and lowest frequency brain waves, ranging from 0.5 Hz to 4 Hz. They occur during the deepest stages of sleep, as well as during coma or anesthesia. They are associated with healing and regeneration².

As you can see, brain activity changes significantly between wakefulness, sleep, and meditation. Some of the main differences are:

• Wakefulness: During eye-open wakefulness, beta waves dominate the brain activity, indicating a high level of alertness and cognition. During eye-closed wakefulness or relaxation, alpha waves become more prominent, indicating a lower level of arousal and a higher level of calmness.
• Sleep: During sleep, brain activity shifts from faster to slower frequencies, following a predictable cycle of sleep stages . The first stage of sleep is characterized by theta waves, indicating a light sleep that is easy to awaken from. The second stage of sleep involves bursts of faster activity called sleep spindles and K-complexes , which help consolidate memory and protect sleep. The third and fourth stages of sleep involve delta waves, indicating a deep sleep that is hard to awaken from and essential for physical recovery. The fifth stage of sleep is called rapid eye movement (REM) sleep , which involves bursts of faster activity similar to wakefulness, indicating a high level of brain activity related to dreaming and emotional processing.
• Meditation: During meditation, brain activity can vary depending on the type and depth of meditation. However, some common patterns are an increase in alpha and theta waves , indicating a relaxed and focused state of mind that enhances creativity and intuition. Some experienced meditators can also produce gamma waves , indicating a heightened state of awareness and insight.