Electroencephalography, or EEG, is a neuroimaging technique used in the scientific study of patterns of brain activity. EEG studies use nets of electrodes that are placed on subjects’ scalps. These electrodes, with the help of electrolytic gel or water, are able to pick up the electrical activity of the neurons in the brain through the scalp, which are then amplified and displayed graphically across time. EEG signals represent the summation in space of the activity of many neurons and are thus not very spatially precise; however, EEG is very temporally accurate, and thus particularly useful for studies in rhythm cognition.
Once EEG data is collected, it can be segmented and averaged to examine the neural response to particular events; see event-related potential (ERP).