Brain waves are the result of the sum of postsynaptic potentials of a large number of neurons in the cerebral cortex. The formation of synchronous rhythm of brain waves is related to the activity of non-specific projection system of cortex and thalamus.

Bioelectricity is one of the basic characteristics of life activities, and all kinds of living things have electrical activities, from whales to bacteria, with bioelectricity of different strengths. In fact, the word "cell" in English also means battery. Countless cells are equivalent to miniature small batteries and are the source of bioelectricity.

Many nerve cells in the human brain are active, which leads to electrical changes. In other words, there is an electric pendulum. And this kind of swing appears on scientific instruments and looks like waves. The electric vibration in the brain is called brainwave. Explaining brain waves in one sentence may be said to be the biological energy produced by brain cells, or the rhythm of brain cell activity.

1924, a German physiologist, saw electric eels emit electricity, thought that human beings must have the same phenomenon, and discovered the electric vibration in the human brain. Later, the brain waves were captured by charts, and the existence of vibration was known. Because this corresponds to human consciousness to a certain extent, it has aroused the interest of many researchers.