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The effects of aging upon the hemodynamic response measured by functional MRI.

Publication ,  Journal Article
Huettel, SA; Singerman, JD; McCarthy, G
Published in: NeuroImage
January 2001

We comparedthe characteristics of the visually evoked hemodynamic response (HDR) in groups of young and elderly adults. Checkerboard stimuli were presented for 500 ms either singly or in pairs separated by a 2-s intrapair interval while gradient-echo echoplanar fMRI images were acquired concurrently every 1 s. Activated voxels, identified by correlation with an empirically derived reference waveform, were found for both groups in cortex along the calcarine sulcus and in the fusiform gyrus, with the mean HDR latency in calcarine cortex peaking approximately 300 ms earlier than the HDR evoked in the fusiform gyrus. On average, younger subjects had twice as many activated voxels as older subjects. The mean HDR had a similar onset time, rate of rise, and peak amplitude in both groups. However, the HDRs of older subjects reached their peak earlier and were more variable across subjects. Despite having average HDR amplitudes similar to those of younger subjects, older subjects had higher noise levels in activated voxels, resulting in lower signal-to-noise ratios. Distribution analyses of voxel statistics (t value, peak amplitude, peak latency) revealed that older subjects had proportionally fewer small-effect-size voxels, due to their increased voxelwise noise. This finding was consistent with the smaller spatial extent of activation in older subjects. To investigate age differences in the refractory period of the visual HDR, the HDR evoked by the second stimulus of each pair was isolated by subtracting the HDR evoked by a single stimulus from the composite HDR evoked by a pair. Recovery measures were similar across the age groups.

Duke Scholars

Published In

NeuroImage

DOI

EISSN

1095-9572

ISSN

1053-8119

Publication Date

January 2001

Volume

13

Issue

1

Start / End Page

161 / 175

Related Subject Headings

  • Photic Stimulation
  • Pattern Recognition, Visual
  • Neurology & Neurosurgery
  • Middle Aged
  • Male
  • Magnetic Resonance Imaging
  • Image Processing, Computer-Assisted
  • Humans
  • Head Movements
  • Female
 

Citation

APA
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MLA
NLM
Huettel, S. A., Singerman, J. D., & McCarthy, G. (2001). The effects of aging upon the hemodynamic response measured by functional MRI. NeuroImage, 13(1), 161–175. https://doi.org/10.1006/nimg.2000.0675
Huettel, S. A., J. D. Singerman, and G. McCarthy. “The effects of aging upon the hemodynamic response measured by functional MRI.NeuroImage 13, no. 1 (January 2001): 161–75. https://doi.org/10.1006/nimg.2000.0675.
Huettel SA, Singerman JD, McCarthy G. The effects of aging upon the hemodynamic response measured by functional MRI. NeuroImage. 2001 Jan;13(1):161–75.
Huettel, S. A., et al. “The effects of aging upon the hemodynamic response measured by functional MRI.NeuroImage, vol. 13, no. 1, Jan. 2001, pp. 161–75. Epmc, doi:10.1006/nimg.2000.0675.
Huettel SA, Singerman JD, McCarthy G. The effects of aging upon the hemodynamic response measured by functional MRI. NeuroImage. 2001 Jan;13(1):161–175.
Journal cover image

Published In

NeuroImage

DOI

EISSN

1095-9572

ISSN

1053-8119

Publication Date

January 2001

Volume

13

Issue

1

Start / End Page

161 / 175

Related Subject Headings

  • Photic Stimulation
  • Pattern Recognition, Visual
  • Neurology & Neurosurgery
  • Middle Aged
  • Male
  • Magnetic Resonance Imaging
  • Image Processing, Computer-Assisted
  • Humans
  • Head Movements
  • Female