Brain wave is a method of recording brain activity by using electrophysiological indicators. When the brain is active, a large number of neurons synchronously generate postsynaptic potentials, which are summed up.

brain waves are spontaneous and rhythmic neuroelectrical activities, whose frequency varies from 1 to 3 times per second and can be divided into four bands, namely, δ (1-3Hz), θ (4-7Hz), α (8-13Hz) and β (14-3Hz).

1. δ wave: the frequency is 1 ~ 3 Hz and the amplitude is 2 ~ 2 μ v. This band can be recorded in the temporal lobe and parietal lobe when people are in infancy or immature intellectual development, and adults are extremely tired and sleepy or anesthetized.

2. θ wave: the frequency is 4 ~ 7 Hz and the amplitude is 5 ~ 2 μ v. This wave is extremely significant in adults who are frustrated or depressed and mental patients. But this wave is the main component of EEG in teenagers (1-17 years old).

3. alpha wave: the frequency is 8 ~ 13 Hz (the average is 1Hz) and the amplitude is 2 ~ 1 μ v. It is the basic rhythm of normal people's brain waves, and its frequency is quite constant if there is no external stimulus. The rhythm is most obvious when people are awake, quiet and close their eyes. When they open their eyes (stimulated by light) or receive other stimuli, the alpha wave disappears immediately.

4. β wave: the frequency is 14 ~ 3 Hz and the amplitude is 1 ~ 15 μ v. This wave appears when people are nervous and excited or excited. When people wake up from nightmares, the original slow-wave rhythm can be immediately replaced by this rhythm.

Extended data:

Brain waves are divided into two parts: the left brain is responsible for numbers, language, logic and analysis; The right brain is responsible for music, art, imagination and creation.

the natural frequency of left brain waves is BeTA, while the natural frequency of right brain waves is Alpha.

Adults generally only use the left brain to think, but ignore the right brain, so the brain waves are mainly BeTA.

Children aged 7-14 are different. They think more with their right brain, so their brain waves are mainly AlphA. At this time, children like music, color, art, imagination and creation. However, with their age and education system, the thinking activities of the brain will gradually shift to the left brain, and the brain waves will also accelerate to BeTA.

Baidu Encyclopedia-Brain Wave