A QEEG calculates how much electricity comes out of the different brain waves. The brain waves are divided into 6 types:
- Delta waves – the slowest, and which dominate during deep sleep and in a coma
- Theta waves – which are dominant in the boundary between wakefulness and sleep
- Alpha waves – which are dominant during the awake state with closed eyes and during meditation
- SMR waves – which are associated with calm in the body, immersion, relaxed concentration and cognitive centering
- Beta waves – for concentration, mental activity and alertness
- High beta waves – which are seen with alertness and stress
All of these brainwave types “belong” to their respective emotional response to situations. If a person is met by a lion in a panic situation, they will usually make a lot of high beta waves. During focus, normally functioning people make beta waves. If instead, one produces theta waves in situations that require concentration and mental activity, it is a sign that the brain is not functioning properly. That’s how it is in general. It is, of course, the case that the brain uses different areas for different functions. Therefore, an EEG is measured in 19 different places for brain mapping.
Similarly, it is e.g. not appropriate if one produces beta activity when falling asleep. At this point it is better to have the brain in alpha activity, which is the idle(inactive) activity of the brain, and gradually fall into theta and delta activity, so that you eventually fall asleep. At the transition to deep sleep it is almost only delta waves that are being made.
How is QEEG brain mapping done?
During EEG measurement with the cap on, a software program captures the electricity from each of the 19 electrodes.
The Q in QEEG stands for the “quantitative“, amount of electricity. And the fact that you can measure the quantitative amount of electricity and compare with what is normal, means that you can make a map of the brain. It’s called a brain map.