Influence of fMRI Smoothing Procedures on Replicability of Fine Scale Motor Localization

Influence of fMRI Smoothing Procedures on Replicability of Fine Scale Motor Localization

Abstract

Recent publications analyzing the influence of spatial smoothing on fMRI brain activation results demonstrated that smoothing may artificially combine activations from adjacent though functionally and anatomically distinct brain regions and that activation from large draining vessels may be smoothed into neighboring neuronal tissue. To investigate whether functional localizations may be artificially shifted by the smoothing procedure we performed replicability measurements. Localization centers of motor hand activations achieved during different conditions (isolated hand movements and simultaneous hand and chin movements) were compared with respect to smoothing effects. The voxel with the highest probability to represent a true positive activation was localized with a non-smoothed and a standard 4 × 4 × 6 mm smoothed correlational data analysis technique. Results show an increase of motor center aberrations between measurements by about 100% due to data smoothing indicating a statistically significant decrease in localization replicability.

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Authors
  • Geissler, A
  • Lanzenberger, R
  • Barth, M
  • Tahamtan, Nick Amirreza
  • Milakara, D
  • Gartus, A
  • Beisteiner, R
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Shortfacts
Category
Journal Paper
Divisions
Workflow Systems and Technology
Journal or Publication Title
NEUROIMAGE
Publisher
Elsevier
Page Range
323-331
Number
2
Volume
24
Date
January 2005
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