Distinct contrast response functions in striate and extra-striate regions of visual cortex revealed with magnetoencephalography (MEG)

Stephen D. Hall*, Ian E. Holliday, Arjan Hillebrand, Paul L. Furlong, Krish D. Singh, Gareth R. Barnes

*Corresponding author for this work

Research output: Contribution to journalArticle

Abstract

Objective: To spatially and temporally characterise the cortical contrast response function to pattern onset stimuli in humans. Methods: Magnetoencephalography (MEG) was used to investigate the human cortical contrast response function to pattern onset stimuli with high temporal and spatial resolution. A beamformer source reconstruction approach was used to spatially localise and identify the time courses of activity at various visual cortical loci. Results: Consistent with the findings of previous studies, MEG beamformer analysis revealed two simultaneous generators of the pattern onset evoked response. These generators arose from anatomically discrete locations in striate and extra-striate visual cortex. Furthermore, these loci demonstrated notably distinct contrast response functions, with striate cortex increasing approximately linearly with contrast, whilst extra-striate visual cortex followed a saturating function. Conclusions: The generators that underlie the pattern onset visual evoked response arise from two distinct regions in striate and extra-striate visual cortex. Significance: The spatially, temporally and functionally distinct mechanisms of contrast processing within the visual cortex may account for the disparate results observed across earlier studies and assist in elucidating causal mechanisms of aberrant contrast processing in neurological disorders. © 2005 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Original languageEnglish
Pages (from-to)1716-1722
Number of pages7
JournalClinical Neurophysiology
Volume116
Issue number7
DOIs
Publication statusPublished - Jul 2005

Keywords

  • contrast response
  • magnetoencephalography (MEG)
  • synthetic aperture magnetometry (SAM)
  • virtual electrode (VE)
  • visual evoked potential (VEP)

Fingerprint Dive into the research topics of 'Distinct contrast response functions in striate and extra-striate regions of visual cortex revealed with magnetoencephalography (MEG)'. Together they form a unique fingerprint.

  • Cite this