Multiple-dipole analysis of visual event-related potentials during oddball paradigms

Abstract

Visual event-related potentials (ERPs) during oddball paradigms with button pressing, silent counting and movement imagery tasks were recorded in right-handed subjects from 32 scalp electrodes. By incorporating the knowledge deduced from the task relevance of the P300 into equivalent current dipole source localization (ECDL), stable multiple ECD solutions with goodness-of-fit (GOF) of more than 90% and confidence limits (CLs) of less than 1 mm were estimated for all the three target P300s. The obtained frontal dipoles were discussed in terms of visual working memory, sustained attention and higher motor control in reference to the previous PET, fMRI and MEG studies. The distributed multiple ECDs may suggest that P300 should be interpreted as being the embodiment of the cortico-limbic-thalamic network accomplishing various cognitive functions.