Your brain never switches off. Whether you're in the middle of a sales call at three in the afternoon or in the deepest sleep at three in the morning, it is working.
What changes is the rhythm it is working at.
Those rhythms are called brainwaves, and they explain a lot.
Why your best ideas turn up in the shower and never at your desk. Why you cannot think straight when you are stressed. Why the first and last minutes of your day matter so much. And why hypnosis works the way it does.
This is the full picture, one state at a time.
What a brainwave actually is
Your brain contains around 86 billion nerve cells, and they talk to each other using tiny electrical signals. When large groups of them fire in rhythm together, the combined activity is strong enough to be picked up by sensors placed on the scalp. That recording is called an EEG. The first one on a human was made in 1924 by a German psychiatrist called Hans Berger.
The rhythm is measured in hertz, which simply means cycles per second. A slow wave rises and falls a couple of times a second. A fast one does it forty times or more.
Scientists group these rhythms into five bands, each named after a Greek letter. From slowest to fastest they are delta, theta, alpha, beta and gamma.
One thing to understand before we go through them. All five are present all the time, in different amounts and in different parts of the brain. Picture a mixing desk with five faders. Every channel is always on, and what changes from moment to moment is which one is turned up. So when I say you are "in alpha", I mean alpha is leading.
The five states at a glance
| Brainwave | Speed | When it leads |
|---|---|---|
| Delta | 0.5 to 4 Hz | Deep, dreamless sleep |
| Theta | 4 to 8 Hz | Drifting off, waking up, deep relaxation, hypnosis |
| Alpha | 8 to 12 Hz | Calm and awake, eyes closed, mind at rest |
| Beta | 12 to 30 Hz | Alert, thinking, talking, working |
| Gamma | 30 Hz and above | Intense focus and moments of insight |
The exact boundaries vary slightly from one textbook to the next. The order never does.
Delta: repair
Delta is the slowest rhythm, and it leads when you are in deep, dreamless sleep. This is the sleep that is hard to be woken from, and if someone does wake you, you feel groggy and lost for a few minutes.
Delta is when the heavy maintenance gets done. Growth hormone is released mainly during deep sleep, the body repairs itself, and the brain moves what you learned that day into long term memory.
Babies spend a huge amount of their time here. Adults get less of it as they get older.
What it means for you: there is no shortcut to delta. When you cut your sleep to fit more work in, this is the part you are cutting, and it is the part that restores you.
Theta: the doorway
Theta leads in the minutes when you are drifting off to sleep and the minutes just after you wake. It is also there in daydreaming, in deep meditation and in deep relaxation.
You know what theta feels like. Images arrive on their own. Thoughts loosen and connect in ways they would not at your desk. Time goes a bit strange. You are aware, and you are not analysing.
Theta is closely tied to memory and emotion. The hippocampus, the part of the brain at the centre of forming and recalling memories, runs on a theta rhythm.
It is also the state most closely linked to hypnosis. When researchers measure the brain during hypnosis, the change that shows up most consistently is a rise in theta.
And it is where children live. A baby's waking brain is dominated by slow waves. Through the early years theta is prominent, and the faster rhythms build gradually as a child grows.
A young child spends much of the day in the kind of brain activity an adult only reaches when drowsy or deeply relaxed, which is a big part of why what we take in when we are young goes in so deep. I have written about that in Why your mind rejects what you tell it.
I think of theta as the doorway between the conscious mind and the subconscious.
What it means for you: you pass through that doorway at least twice a day, on the way into sleep and on the way out of it. What you put in front of your mind at those two moments matters.
Alpha: calm and awake
Alpha leads when you are awake and relaxed, with your mind not fixed on anything in particular. Close your eyes and alpha rises within seconds. Open them and start concentrating, and it drops away.
It was the first rhythm Hans Berger identified, which is why it got the first letter of the alphabet.
Alpha is the walk with no headphones in. The shower. Staring out of the window on a train. It is the brain turning down the noise from outside and turning inward.
That is why ideas arrive in the shower. In studies of "aha" moments, researchers found alpha rising just before the answer came, as the brain quietened the outside world to let something new come through.
What it means for you: alpha is the state you skip when you go from bed to phone to laptop. If you never give your mind a quiet spell, you are leaving your best thinking on the table.
Beta: getting things done
Beta leads when you are awake, alert and engaged. Talking, planning, solving, deciding, selling. It runs your working day, and you need it.
The range within beta matters. At the lower end it is calm, clear focus. At the upper end it goes with stress, racing thoughts and feeling wired. If you run a business you will know that end well: it is your mind still working through the list at eleven at night when your body is done.
In fast beta your attention narrows onto whatever is in front of you. That is exactly what you want in a crisis. It is a poor state for creative thinking, for perspective, or for changing a belief.
What it means for you: if you cannot think your way out of a problem, look at the state you are trying to think from. More effort in fast beta gives you more of the same thoughts, faster.
Gamma: everything connecting
Gamma is the fastest rhythm. It is linked to sharp attention, to holding several things in mind at once, and to the brain pulling information from different areas into one clear picture.
In those same "aha" studies, a burst of gamma was recorded at the instant the answer landed. Very experienced meditators have also been found to produce unusually strong gamma.
Gamma is the hardest rhythm to measure from outside the skull, so it is the one we know least about. What the insight research does show is the order: a quiet spell first, then the flash.
What it means for you: the breakthrough rarely comes while you are grinding at the problem. It comes after you step back from it.
What your brain does over a normal day
When you wake, you come up through the gears: out of the slow rhythms of sleep, through theta and alpha, and into beta as the day takes hold.
Through the day you sit mainly in beta, dipping into alpha when you pause, and spiking higher when the pressure is on.
In the evening you go back down the same way. Beta gives way to alpha as you wind down, then theta as you drift, then delta in deep sleep.
Through the night you cycle roughly every ninety minutes between light sleep, deep sleep and dream sleep. During dreams your brain speeds up again, and its activity looks surprisingly close to being awake. It is why a dream can feel completely real while you are in it.
Where hypnosis fits
People expect hypnosis to be a kind of sleep. You are awake and aware throughout.
What happens is that your body relaxes, your attention narrows, the fast activity settles and the slower rhythms, theta in particular, come up. It is the same territory you pass through every night on the way to sleep. In a session we go there on purpose and stay there long enough to work.
That is the reason hypnosis can reach what talking and thinking cannot. In beta, you analyse and argue. In theta, that analysing has stepped back and the subconscious is far more open.
It is also why I give my clients personalised audio to listen to first thing in the morning and last thing at night. Those are the two points in the day when your brain is already there.
If you want to know what a session is like from the inside, read What actually happens in a hypnosis session.
Five things you can do with this
- Leave your phone alone for the first ten minutes of the day. You wake up through theta and alpha. Picking up your phone pulls you straight into beta, on somebody else's agenda.
- Close your eyes between tasks. Two minutes, eyes shut, breathing slowly. Alpha rises within seconds of your eyes closing. It is one of the most reliable findings in brain research and it costs you nothing.
- Take the problem for a walk. When you are stuck, you are usually stuck in fast beta. Step away from the screen and let alpha do what effort cannot.
- Protect your deep sleep. Delta is when you are repaired. Treat it as part of the work.
- Choose what goes in last thing at night. You are heading through theta on the way to sleep. Give your mind something better than the news and tomorrow's worries.
The state comes first
High performers are told to work on their thinking. Thinking happens inside a state, and the state decides what kind of thinking is available to you.
The same goes for change. A belief that was laid down in a slow, open state is very hard to shift from a fast, guarded one. That is why understanding a pattern so rarely moves it, which I have covered in Why understanding your problem doesn't fix it, and it sits behind the way I work in The Rewire Code.
Your external reality is a direct reflection of your internal state. Your brainwaves are one way of seeing that internal state on a screen.