During the process of EEG, in addition to recording the EEG when the patient is awake and quiet, some evoked tests are also done in the absence of special contraindications, with the aim of increasing the occurrence of certain types of EEG abnormalities. Specifically, these include: eye opening and closing evoked tests, hyperventilation, sleep deprivation, sleep EEG, flash stimulation, etc. Patients should actively cooperate with their physicians to perform these evoked tests. In patients with photosensitive epilepsy, it is important to explain the situation to the physician before the test because flash stimulation may induce seizures back in the patient.