title: The pain-evoked P2 is not a P3a event-related potential.
abstract: The topographic pattern and latency of the P2 component of the somatosensory evoked potential elicited by painful electrical stimulation of the sural nerve was compared to the P3a event-related potential evoked by an infrequent task-irrelevant (deviant) innocuous sural nerve stimulus presented as part of the deviant-odd ball paradigm. Conditions typically used to record the sural nerve pain-evoked P2 (multiple stimulus levels, short fixed inter-stimulus intervals, and the subjects engaged in a pain rating task) did not elicit a P3a. The P3a was elicited when the painful stimuli were presented at a long and variable inter-stimulus interval. When present, the P3a occurred immediately following P2. These findings demonstrate that P2 is not a pain-evoked P3a. Rather, the response properties and latency of P2 present the possibility that it indexes a stimulus evaluation process where the sensory input is compared to an environmental template maintained by working memory.
authors.affiliation: Department of Psychology, Clarkson University, Potsdam, NY, USA. rdowman@clarkson.edu
authors.forename: Robert
authors.initials: R
authors.lastname: Dowman
mesh_terms: D000293:Adolescent; D000328:Adult; D000344:Afferent Pathways / Q000502:physiology*; D001288:Attention / Q000502:physiology; D018913:Event-Related Potentials, P300 / Q000502:physiology*; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology; D009431:Neural Conduction / Q000502:physiology; D009619:Nociceptors / Q000502:physiology*; D010146:Pain / Q000503:physiopathology*; D010147:Pain Measurement; D017288:Pain Threshold / Q000502:physiology; D010465:Perception / Q000502:physiology; D010812:Physical Stimulation; D011930:Reaction Time / Q000502:physiology; D013497:Sural Nerve / Q000502:physiology