There are 5 basic brainwave patterns, and 5 basic stages of sleep. It’s tempting to think that each brainwave state neatly corresponds to a sleep stage, but I’ve not discovered an equivalence. First, let’s explore the various brainwave patterns, then the sleep stages, and finally we’ll see where there may be overlap and differences.
Brainwave Patterns & Associations
There are 5 basic brainwave patterns. The brain waves are measured in Hertz, or cycles per second. The lower the hertz, the slower the brainwave.
If you do a search on Google for Hertz range of the various brainwave states, you will find mixed results. Even scientists don’t seem to agree on the range for the various brainwave states. Some will say 14 Hz is a beta pattern, others will say it’s in the high alpha range. The range I’ve provided below was pulled from an article on Google Scholar.
Brainwave Pattern Range in Hertz (Hz)
- Gamma 31-100 Hz
- Beta 13-30 Hz
- Alpha 8-13 Hz
- Theta 4-8 Hz
- Delta 0.5-4 Hz
Characteristics of Various Brainwave States
- Gamma – insight, peak focus, expanded consciousness, compassion
- Beta – alertness, cognition, concentration, anxiety
- Alpha – relaxation, visualization, creativity
- Theta – meditation, intuition, memory
- Delta – sleep, healing, detached awareness
Delta brainwaves are often described as the brainwaves you have in sleep. There are definite similarities between slow wave sleep, and delta waves. However, not everyone experiences delta brainwaves ONLY when sleeping.
Therefore, although there are similarities, one does not equal the other. It will be important to keep this in mind as you continue reading.
The 5 Stages of Sleep
Your brain needs to spend adequate time in each of the sleep stages in order for you to function properly.
Level 1: drifting in and out, slow eye movement
Level 2: still eyes, slow brain activity, sleep spindles
Levels 3 & 4: these are so similar that I’m not sure why they’re different levels. In 3 & 4, it is slow-wave, deep sleep. This is when some people sleepwalk
R.E.M. or Paradoxical Sleep: this accounts for about 20% of our overall sleeping time. This stage is characterized by rapid eye movement, increased pulse and breathing, and sleep paralysis or paralyzed muscles.
Sleep Stages and Brainwave Patterns
If I were to map out rough equivalences of brainwave patterns to sleep stages, it would look something like this:
- Beta (alert, attentive and wide awake)
- Alpha (deeply relaxed)
- Theta (light-to-deep sleep)
- Delta (deep sleep)
- REM (dreaming sleep)
As you close your eyes and drift into sleep, your brain shifts through the following cycles:
Wakefulness–Gamma and Beta – These brainwaves are associated with being awake and alert. Some studies associate these high Hertz states with anxiety, panic, fear, compassion and peak performance.
People spend the majority of their time, at least during the day, in a beta brainwave state. However, it is common that people will slip down into alpha or theta states as they daydream, or shoot up into the gamma state when experiencing a flash of insight.
Stage 1–Alpha Waves: This light sleep typically lasts between 1 and 10 minutes.
You are lightly asleep, and you can quickly return to being fully awake.
- Twilight: A high alpha brainwave state between wakefulness and sleep; this is where a lot of tossing and turning can happen. As a person falls through the alpha brainwaves towards the deeper, slower theta brainwaves, memories get jogged, or creative ideas spill loose. This is because your brain better assimilates learning and access memory when you are relaxed. (Yes, naps help you learn. I propose naptime for everyone regardless of age. But, I digress.)
Stage 2–Theta Waves: Stage 2 is also referred to as light sleep, and is characterized by a slowing heart rate and a decrease in body temperature. Your brain starts to emit larger waves and it becomes harder to wake you up.
I’ve not read any research to support this, however I would guess that the sleep spindles common in stage 2 sleep are bursts of gamma waves. Gamma brainwaves tend to happen in little bursts nested into other brainwave patterns like alpha or theta patterns, just like the sleep spindles in stage 2 sleep which is why I think they might somehow be connected.
Hopefully a scientist out there will study this possible connection, and let me know what they find!
Stage 3 & 4–Delta Waves: Associated with the deepest, most restorative sleep. Total loss of body awareness. If you are woken during this stage of sleep, you are going to feel disoriented.
- Deep Sleep: Predominantly Delta waves; this is the most difficult stage to wake from, and when you are awakened in this stage, you will usually be sleepy and disoriented.
REM–Multiple Wave Patterns: The first Rapid Eye Movement sleep stage lasts around 10 minutes and usually happens after having been asleep at least 90 minutes. Each of your later REM stages gets longer, and the final one may last up to an hour.
REM sleep is characterized by multiple brainwave patterns, typically theta and delta. During this stage of sleep we have powerful dreams. Scientists postulate that REM sleep may play an important role in learning and memory, and is also likely to help regulate and process emotions.
- Dreaming/REM: Relaxing, dreamlike sleep, mainly in the theta state. REM sleep is thought to play a role in memory consolidation, the synthesis and organization of cognition, and mood regulation.
Each sleep stage roughly corresponds to a brainwave pattern. There is no absolute one-to-one equivalence despite the fact that sleep stages are in part defined by their accompanying brainwaves.
In other words, having a particular brainwave pattern does not guarantee you are in a certain sleep stage. For example, people who meditate can become skilled at remaining aware even while having very slow delta brainwaves.
Please keep in mind, your brainwaves are not beta when awake, and delta when asleep. That’s a gross oversimplification. Rather everyone naturally slips into and out of multiple brainwave patterns throughout the day and night. Your brainwaves naturally undulate and change, like the surface of the ocean.