EEG​

​

Neurons are the building blocks and the information processing units of the brain. 85 billion neurons make up the human brain and communicate with other neurons primarily through electrochemical signals. The electrical activity differs from brain region to brain region depending upon what the brain is doing at the time. Electroencephalograph (EEG) is an instrument for receiving and recording the electrical potentials produced by active brain cells. The EEG system consists of an amplifier to magnify the electrical currents produced by brain cells which are received through sensors placed on the scalp. The experimental use of EEG often relies on evoked potentials or event-related potentials, in which the EEG activity is time-locked to the presentation of experimental stimuli and averaged over repetitions.