The document discusses electroencephalography (EEG), which is the study of the electrical activity of the brain. EEG measures this electrical activity through electrodes placed on the scalp. The brain consists of four main parts: the cerebrum, cerebellum, medulla oblongata, and spinal cord. There are two types of action potentials in the brain - inhibitory postsynaptic potentials (IPSPs) and excitatory postsynaptic potentials (EPSPs) - which influence the likelihood of a neuron firing. Evoked potentials are also discussed, which are electrical changes in the brain in response to external stimuli like light or sound.