On the processing of spatial frequencies as revealed by evoked-potential source modeling

J. L. Kenemans, J. M P Baas, George R Mangun, M. Lijffijt, M. N. Verbaten

Research output: Contribution to journalArticle

74 Scopus citations

Abstract

Objectives and methods: Visually evoked potentials (VEPs) are known to be sensitive to spatial frequency, especially in the time range between 50 and 100 ms post-stimulus. In two experiments we localized the cortical activity elicited by stimuli of varying spatial frequency in scalp-recorded brain potentials, using multi-electrode recordings and dipole-source analysis. Results: Low spatial frequencies (<1 c/d) activated relatively lateral occipital areas, the orientation of the neural ensembles involved being predominantly perpendicular to the scalp surface. In contrast, high spatial frequencies (>4 c/d) induced activation of more medial occipital areas with the predominant orientation of the sources being much more parallel to the scalp surface. Furthermore, at about 100 ms latency the lateral-occipital response to low spatial frequencies was stronger in the right hemisphere; no such asymmetry was found for the responses to the high spatial frequencies. These findings were consistent across varying recording conditions, individual subjects, subject populations, stimulus characteristics (grating orientation, grating vs. checkerboard), and task conditions (active vs. passive). Conclusion: The results indicate that there are differences in sensitivity to specific spatial frequencies between primary and secondary visual areas, as well as between the right and the left hemispheres. Copyright (C) 2000 Elsevier Science Ireland Ltd.

Original languageEnglish (US)
Pages (from-to)1113-1123
Number of pages11
JournalClinical Neurophysiology
Volume111
Issue number6
DOIs
StatePublished - Jun 1 2000
Externally publishedYes

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Keywords

  • Dipole-source analysis
  • Evoked potential
  • Occipital cortex
  • Spatial frequency

ASJC Scopus subject areas

  • Clinical Neurology
  • Radiology Nuclear Medicine and imaging
  • Neurology
  • Sensory Systems
  • Physiology (medical)

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