What is the theta state? Scientists who study the brain, including those involved in the field of sleep science, use an EEG (electroencephalogram) to measure the electrical activity of neurons in the brain. Brainwaves refer to the various different oscillatory patterns in this neural activity, measured in cycles, or Hertz (Hz): each wave pattern is assigned a letter from the Greek alphabet, from alpha all the way to gamma, and is associated with a level of neural activity. The theta state refers to the level of activity in the brain that occurs during sleep and dreaming, and observing the brain’s transition into a theta state may give researchers a window on how the brain can achieve lucid dreams through inducing theta waves.
Brainwaves have the potential to tell us a lot about how consciousness operates in mammals, including humans. The five brainwave states that have been observed and documented in humans and primates are, from least to most active:
-Delta (<4Hz): delta is the state of lowest brain activity, and normally occurs only during deep (non-REM) sleep.
-Theta (4-7 Hz): the state we’re concerned with here, theta waves occur during REM and lighter states of sleep, in deep meditation, trance states and states of active visualization. You could of theta as the dream state in human beings.
-Alpha (8-13 Hz): a low-activity waking state, alpha waves occur when a person is in a state of calm alertness, such as just after waking.
-Beta (13-25 Hz): beta waves represent the working state of the brain, and show up when someone engages in active thinking and problem solving.
-Gamma (25-100 Hz; 40 Hz typical): the highest frequency of brainwaves so far observed, gamma waves occur when the brain is processing and integrating information from many different regions of the nervous system. Gamma waves are associated with high-level cognitive activity and information synthesis, and may also occur in lucid dreaming, as we’ll look at below.
The exact role of theta waves in humans is not entirely clear. Scientists aren’t sure if theta waves originate from the hippocampus (as in some other mammals like rats) or the cortex in humans. For ethical reasons, typically researchers can only use topical electrodes to measure brainwaves in humans, not invasive devices. However, the data researchers do have on the human theta state suggests that it occurs during the transition from sleep to wakefulness and vice versa, typically in a one-second burst. In general, theta waves seem to reflect states of physical and mental relaxation (as opposed to arousal), which is why researchers have also observed the theta state in people who weren’t asleep but engaged in deep meditation, visualization, or concentration on creative projects.
This connection between the theta state, dreaming, and active visualization is why some sleep researchers suggest that conscious induction of the theta state may be key to purposely achieving lucid dreams. Gaining the ability to consciously slip into a state of deep relaxation while remaining conscious is the lucid dreaming method advocated by dream researcher Stephen LaBerge to reliably achieve what he called a wake-induced lucid dream, in which you transition directly into a dream without any loss of awareness.
Perhaps even more intriguingly, some researchers have speculated that in lucid dreaming, the brain may actually transition directly from a theta state to a high activity gamma state! Gamma waves seem to occur when the brain is processing and integrating visual information and creating associations between what it sees and related memories and ideas. Associated with states of maximal awareness and sensitivity, gamma states have been observed in with Buddhist monks with decades of meditation experience, which suggests achieving a gamma level of brain activity is a trainable skill, much like lucid dreaming itself.
Training yourself to enter a theta or dream state involves cultivating techniques of active visualization to draw yourself into the twilight state of relaxation that precedes lucid dreaming. I’ve described relaxation techniques in greater detail in a different article, but one fast technique I’ll mention here is the use of binaural beats or isochronic tones: these are two types of music files engineered to put you into a state of deep relaxation using musical tones. Meant to be played in stereo and ideally listened to with headphones, these beats have on average a 6Hz difference between them, so that one ear might hear a tone with a frequency of 120Hz while the other ear will hear a 126 Hz beat. The theory goes that in trying to reconcile the different beats, the brain syncs to the difference at a frequency of 6Hz, which is within the theta state range.
There’s some debate about which type of tones work best for inducing dream states, with some people claiming that isochronic tones are stronger and more reliable. However, both types of files can produce some of the effects associated with that valuable mind-awake body-asleep twilight state. These include feeling mentally and physically relaxed; hypnagogic phenomena such as hallucinating sounds and seeing patterns, colors or shapes behind your eyes; body distortions such as feelings of floating and altered limb position; and even conscious awareness of emerging dream scenes (though this usually requires practice).
In reality, our brain activity throughout the day is usually a combination of one or more of the above brain states. The key is to learn to how to switch from an active beta state to a more relaxed alpha, and from there to the theta state when it’s time for you to go to bed. Whether you’re interested in entering the theta state for lucid dream work, or just so you can get to sleep more easily at night, learning a few relaxation techniques can make it easy for you to ramp down from the active beta state most of us inhabit during the day and access the more meditative and creative modes of your brain.