Habituation: an event-related potential and dipole source analysis study

The goal of this study was to investigate habituation processes in the brai n, and in particular, to identify the brain structures involved in these pr ocesses. Therefore, event-related potentials (ERPs) were recorded in respon se to a series of repeated, task-irrelevant, salient stimuli presented agai nst the background of a cognitive task which required the subjects to atten d to a fixation sign on a TV screen. Stimuli were presented randomly in one of four possible quadrants of the TV screen. Dipole analyses were performe d in order to localize the source of stimulus repetition effects (habituati on). As expected, there was a decrease in amplitude of the N1 and P3 compon ents as a function of stimulus repetition; habituation of N1 occurred faste r than that of the P3 component. It is suggested from the results of dipole analyses that the N1 effect concerns diffuse cortical activation. The P3 h abituation effect seemed to involve the temporal cortex especially. (C) 200 0 Elsevier Science B.V. All rights reserved.