How Does It Work
Brainwaves
Thinking occurs when the cells in our brains exchange electrical and chemical signals. Brainwaves are a measure of the electrical activity of our brains. We can map brainwaves using instruments such as an EEG.
Brainwave activity indicates what is going on in the mind. Brainwave patterns can be used to measure a subject's mental state. The following table shows the four common frequencies that all of us experience daily.
| State | Frequency range | State of mind |
| Delta | 0.5Hz - 4Hz | Deep sleep |
| Theta | 4Hz - 8Hz | Drowsiness and first stage of sleep |
| Alpha | 8Hz - 14Hz | Relaxed but alert |
| Beta | 14Hz - 30Hz | Highly alert and focused |
Measuring brainwaves using magneto encephalography
