Event-related potentials (ERPs) are a series of negative and positive voltage deflections of the electroencephalogram (EEG) that are time locked typically to either sensory or cognitive events and can be recorded in both humans and animals. It has been suggested that the stimuli that evoke ERP components influence oscillatory changes within the dynamics of ongoing EEG rhythms [23-30]. This synchronization or enhancement of ongoing EEG oscillations by a time locked cognitive and/or sensory process is termed an event-related oscillation (ERO) [31-33]. EROs are thought to arise by a “phase re-ordering”, or realignment, of the background EEG in several frequency bands [34-35]. Phase locking of EROs can be measured in both humans [22, 33] and more recently in rodent models [36-39], allowing for translational studies to be conducted.
