Determine the uses of Electrical Recording - Brain function
We can also learn about brain function by recording its electrical activity. In electroencephalography (EEG) and the closely-related potential (ERP) recording, electrodes are attached to the scalp and the amplified electrical activity detected by them is displayed on chart recorder or computer screen. Surface recording is possible because the electrochemical activity of the brain is conducted passively through the meninges (protective membranes surrounding the brain), and the skull to scalp. The recorded voltages represent the summed activity of millions of neurons in the area of brain closest to the recording electrode so, in order to get an idea about the spatial distribution of activity, several separate channels of EEG corresponding to electrodes in different positions on the head can be recorded simultaneously. This procedure has proved invaluable in the diagnosis of epilepsy and in the identification of sleep-related disorders.