In order to diagnose a disease in a patient’s brain, doctors often give an EEG. When you do an EEG, do you have to energize the brain? Actually, it is not necessary. The brain itself is like a generator, which can produce electricity, but the voltage produced is too weak, only about 1 microvolt, which is difficult to measure. Therefore, when doing EEG, the doctor always uses the brain motor to amplify the patient’s brain voltage by more than one million times, so that it is almost about 1 volt, which is close to the voltage of a dry cell battery, and then the amplified brain voltage is depicted on the recording paper, so as to get the curve of the brain voltage, which is also known as the electroencephalogram. EEG provides a scientific basis for the diagnosis of medical conditions.