Open AccessCortical sources of the early components of the visual evoked potential
Author(s) -
Di Russo Francesco,
Martínez Antígona,
Sereno Martin I.,
Pitzalis Sabrina,
Hillyard Steven A.
Publication year - 2002
Publication title -
human brain mapping
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.005
H-Index - 191
eISSN - 1097-0193
pISSN - 1065-9471
DOI - 10.1002/hbm.10010
Subject(s) - neuroscience , extrastriate cortex , fusiform gyrus , visual cortex , psychology , p200 , visual system , occipital lobe , visual n1 , gyrus , functional magnetic resonance imaging , visual perception , anatomy , perception , medicine
This study aimed to characterize the neural generators of the early components of the visual evoked potential (VEP) to isoluminant checkerboard stimuli. Multichannel scalp recordings, retinotopic mapping and dipole modeling techniques were used to estimate the locations of the cortical sources giving rise to the early C1, P1, and N1 components. Dipole locations were matched to anatomical brain regions visualized in structural magnetic resonance imaging (MRI) and to functional MRI (fMRI) activations elicited by the same stimuli. These converging methods confirmed previous reports that the C1 component (onset latency 55 msec; peak latency 90–92 msec) was generated in the primary visual area (striate cortex; area 17). The early phase of the P1 component (onset latency 72–80 msec; peak latency 98–110 msec) was localized to sources in dorsal extrastriate cortex of the middle occipital gyrus, while the late phase of the P1 component (onset latency 110–120 msec; peak latency 136–146 msec) was localized to ventral extrastriate cortex of the fusiform gyrus. Among the N1 subcomponents, the posterior N150 could be accounted for by the same dipolar source as the early P1, while the anterior N155 was localized to a deep source in the parietal lobe. These findings clarify the anatomical origin of these VEP components, which have been studied extensively in relation to visual‐perceptual processes. Hum. Brain Mapping 15:95–111, 2001. © 2001 Wiley‐Liss, Inc.