ABSTRACT
Event-related potentials (ERP) are small perturbations of the spontaneous electrical activity of the brain time-locked to a defineable event such as the onset of a stimulus or the initiation of a movement. ERP recording facilities provided by a clinical neurophysiology department which routinely records only exogenous ERPs may not be appropriate for studies of endogenous components. Very little work has attempted to develop endogenous ERPs as diagnostic tools in a neuropsychological context, with the exception of studies investigating P3 latency in dementia. ERP recordings are carried out by referring all scalp electrodes to a single distant reference electrode, so that the relative amplitude of ERPs at different scalp sites can be assessed as unambiguously as possible. The employment of ERPs in neuropsychological populations, whether as an aid to understanding the reasons for a particular cognitive impairment, or as a means of increasing knowledge about the cognitive and neuropsychological basis of ERP components, is in its infancy.
