High-resolution BOLD fMRI measurements of local orientation-dependent contextual modulation show a mismatch between predicted V1 output and local BOLD response

Vision Res. 2010 Jun 18;50(13):1214-24. doi: 10.1016/j.visres.2010.04.005. Epub 2010 Apr 9.

Abstract

The blood oxygenation level-dependent (BOLD) functional MRI response to suppressive neural activity has not been tested on a fine spatial scale. Using Gabor patches placed in the near periphery, we precisely localized individual regions of interest in primary visual cortex and measured the response at a range of contrasts in two different contexts: with parallel and with orthogonal flanking Gabor patches. Psychophysical measurements confirmed strong suppression of the target Gabor response when flanked by parallel Gabors. However, the BOLD response to the target with parallel flankers decreased as the target contrast increased, which contradicts psychophysical estimates of local neural activity.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Contrast Sensitivity / physiology
  • Female
  • Humans
  • Magnetic Resonance Imaging / methods*
  • Photic Stimulation*
  • Psychophysics
  • Sensory Thresholds
  • Visual Cortex / physiology*
  • Young Adult