TY  - JOUR
AU  - Barnikol, U. B.
AU  - Amunts, K.
AU  - Dammers, J.
AU  - Mohlberg, H.
AU  - Fieseler, T.
AU  - Malikovic, A.
AU  - Zilles, K.
AU  - Niedeggen, M.
AU  - Tass, P. A.
TI  - Pattern reversal visual evoked responses of V1/V2 and V5/MT as revealed by MEG combined with probabilistic cytoarchitectonic maps
JO  - NeuroImage
VL  - 31
SN  - 1053-8119
CY  - Orlando, Fla.
PB  - Academic Press
M1  - PreJuSER-51350
SP  - 86 - 108
PY  - 2006
N1  - Record converted from VDB: 12.11.2012
AB  - Pattern reversal stimulation provides an established tool for assessing the integrity of the visual pathway and for studying early visual processing. Numerous magnetoencephalographic (MEG) and electroencephalographic (EEG) studies have revealed a three-phasic waveform of the averaged pattern reversal visual evoked potential/magnetic field, with components N75(m), P100(m), and N145(m). However, the anatomical assignment of these components to distinct cortical generators is still a matter of debate, which has inter alia connected with considerable interindividual variations of the human striate and extrastriate cortex. The anatomical variability can be compensated for by means of probabilistic cytoarchitectonic maps, which are three-dimensional maps obtained by an observer-independent statistical mapping in a sample of ten postmortem brains. Transformed onto a subject's brain under consideration, these maps provide the probability with which a given voxel of the subject's brain belongs to a particular cytoarchitectonic area. We optimize the spatial selectivity of the probability maps for V1 and V2 with a probability threshold which optimizes the self- vs. cross-overlap in the population of postmortem brains used for deriving the probabilistic cytoarchitectonic maps. For the first time, we use probabilistic cytoarchitectonic maps of visual cortical areas in order to anatomically identify active cortical generators underlying pattern reversal visual evoked magnetic fields as revealed by MEG. The generators are determined with magnetic field tomography (MFT), which reconstructs the current source density in each voxel. In all seven subjects, our approach reveals generators in V1/V2 (with a greater overlap with V1) and in V5 unilaterally (right V5 in three subjects, left V5 in four subjects) and consistent time courses of their stimulus-locked activations, with three peak activations in V1/V2 (contributing to C1m/N75m, P100m, and N145m) and two peak activations in V5 (contributing to P100m and N145m). The reverberating V1/V2 and V5 activations demonstrate the effect of recurrent activation mechanisms including V1 and extrastriate areas and/or corticofugal feedback loops. Our results demonstrate that the combined investigation of MEG signals with MFT and probabilistic cytoarchitectonic maps significantly improves the anatomical identification of active brain areas.
KW  - Adult
KW  - Attention: physiology
KW  - Brain Mapping
KW  - Evoked Potentials, Visual: physiology
KW  - Geniculate Bodies: physiology
KW  - Humans
KW  - Image Processing, Computer-Assisted
KW  - Magnetoencephalography
KW  - Male
KW  - Models, Statistical
KW  - Neurons: physiology
KW  - Neurons: ultrasonography
KW  - Pattern Recognition, Visual: physiology
KW  - Reaction Time: physiology
KW  - Reference Values
KW  - Signal Processing, Computer-Assisted
KW  - Visual Cortex: anatomy & histology
KW  - Visual Cortex: physiology
KW  - Visual Pathways: physiology
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
C6  - pmid:16480895
UR  - <Go to ISI:>//WOS:000238012200009
DO  - DOI:10.1016/j.neuroimage.2005.11.045
UR  - https://juser.fz-juelich.de/record/51350
ER  -