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Evidence for a refractory period in the hemodynamic response to visual stimuli as measured by MRI.

Publication ,  Journal Article
Huettel, SA; McCarthy, G
Published in: NeuroImage
May 2000

We investigated the effects of paired presentations of visual stimuli upon the evoked hemodynamic response of visual cortex measured by magnetic resonance imaging (MRI). Stimuli were identical 500-ms high-contrast checkerboard patterns, presented singly or with an interpair interval (IPI) of 1, 2, 4, or 6 s (onset-to-onset), followed by an intertrial interval of 16-20 s. Images were acquired at 1.5 Tesla using a gradient-echo echoplanar imaging sequence sensitive to blood-oxygenation-level dependent (BOLD) contrast. Single checkerboards evoked a hemodynamic response from visual cortex characterized by a rise at 3 s, peak activation at 5 s, and return to baseline by 10 s. We subtracted subjects' single-stimulus hemodynamic response from their paired-stimulus responses to isolate the contribution of the second stimulus. If the hemodynamic responses were fully additive, the residual should be a time-shifted replica of the single stimulus response. However, the amplitude of the hemodynamic response to the second checkerboard was smaller, and the peak latency was longer, than for the first. Furthermore, the amplitude decrement was dependent upon IPI, such that the response to the second stimulus at 1 s IPI was only 55% of that to a single stimulus, with recovery to 90% at a 6 s IPI. Peak latency was similarly dependent upon IPI with longer latencies observed for shorter IPIs. These results demonstrate an extended refractory period in the hemodynamic response to visual stimuli consistent with that shown previously for neuronal activity measured electrophysiologically.

Duke Scholars

Published In

NeuroImage

DOI

EISSN

1095-9572

ISSN

1053-8119

Publication Date

May 2000

Volume

11

Issue

5 Pt 1

Start / End Page

547 / 553

Related Subject Headings

  • Visual Cortex
  • Regression Analysis
  • Refractory Period, Electrophysiological
  • Reaction Time
  • Photic Stimulation
  • Neurology & Neurosurgery
  • Male
  • Magnetic Resonance Imaging
  • Humans
  • Hemodynamics
 

Citation

APA
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ICMJE
MLA
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Huettel, S. A., & McCarthy, G. (2000). Evidence for a refractory period in the hemodynamic response to visual stimuli as measured by MRI. NeuroImage, 11(5 Pt 1), 547–553. https://doi.org/10.1006/nimg.2000.0553
Huettel, S. A., and G. McCarthy. “Evidence for a refractory period in the hemodynamic response to visual stimuli as measured by MRI.NeuroImage 11, no. 5 Pt 1 (May 2000): 547–53. https://doi.org/10.1006/nimg.2000.0553.
Huettel SA, McCarthy G. Evidence for a refractory period in the hemodynamic response to visual stimuli as measured by MRI. NeuroImage. 2000 May;11(5 Pt 1):547–53.
Huettel, S. A., and G. McCarthy. “Evidence for a refractory period in the hemodynamic response to visual stimuli as measured by MRI.NeuroImage, vol. 11, no. 5 Pt 1, May 2000, pp. 547–53. Epmc, doi:10.1006/nimg.2000.0553.
Huettel SA, McCarthy G. Evidence for a refractory period in the hemodynamic response to visual stimuli as measured by MRI. NeuroImage. 2000 May;11(5 Pt 1):547–553.
Journal cover image

Published In

NeuroImage

DOI

EISSN

1095-9572

ISSN

1053-8119

Publication Date

May 2000

Volume

11

Issue

5 Pt 1

Start / End Page

547 / 553

Related Subject Headings

  • Visual Cortex
  • Regression Analysis
  • Refractory Period, Electrophysiological
  • Reaction Time
  • Photic Stimulation
  • Neurology & Neurosurgery
  • Male
  • Magnetic Resonance Imaging
  • Humans
  • Hemodynamics