Some people think that EEG is the use of electricity to examine the head and therefore fear that it will damage brain tissue. This is a misconception. In fact, EEG is a graphical representation of the electrical currents generated by the brain itself and traced by the EEG instrument, which does not damage the human brain at all. All living cells are constantly generating static electricity, called “bioelectricity”. This current is so small that it cannot be measured by ordinary methods, but after magnifying this bioelectricity millions of times, it can be drawn on a graph. If the drawing is of the brain, it is called an electroencephalogram. Similarly, there are electrocardiograms, electromyograms, and gastric electrograms. The ECG machine only magnifies a few thousand times, while the EEG machine has to be magnified hundreds of thousands of times because the brain is wrapped in a thick skull. Although the lines are curved, they have their own regularity and scientific nature, so professionals can understand its meaning and make a normal or abnormal judgment accordingly. In recent years, there is another kind of “EEG topography”, which is a device connected with an EEG machine and a specially designed electronic computer. The brain bio-currents released by the EEG machine are recorded on disk and input into the electronic computer, which is processed and transformed into different shades of hue graphics, displayed on a fluorescent screen and printed on paper. Therefore, it is no longer a curve but a “topographic map”. The basic principles of EEG and EEG topography are the same, both reflecting the bioelectric activity of brain cells, except that the latter can easily remove artifacts and clearly show the specific distribution of various waveforms in the brain, and is more accurate. EEG and EEG topography reflect the bioelectricity of the brain tissue and, like ECG, do not cause any damage to the human body.