Event-Related Paradigms

Synonyms

Auditory and visual evoked potentials; ERP’s; Evoked potentials

Definition

Event-related potentials (ERPs) are time locked and stereotyped brain responses to some “event.” An event-related potential (ERP) is the measured brain electrophysiological response that is the direct result of a specific sensory, cognitive, or motor event. The stimulus can be a sound, a simple visual pattern, a mental event, or thoughts such as recognition of a specific target stimulus or the absence of a stimulus as when an increased time elapses between stimuli. The recorded brain response is a very small electrical voltage of between 1 and 100 millionths of a volt and is recorded over the scalp by a very sensitive amplifier and computer averaging equipment that can recognize it as a consistency in the seemingly random waveforms of the overlying EEG.

The response can be a singular waveform or a series of waveforms that indicate the chain of processors that respond in sequence to the stimulus as the...