The continuing challenge of understanding and modeling hemodynamic variation in fMRI

Neuroimage. 2012 Aug 15;62(2):1017-23. doi: 10.1016/j.neuroimage.2012.02.015. Epub 2012 Feb 14.


Interpretation of fMRI data depends on our ability to understand or model the shape of the hemodynamic response (HR) to a neural event. Although the HR has been studied almost since the beginning of fMRI, we are still far from having robust methods to account for the full range of known HR variation in typical fMRI analyses. This paper reviews how the authors and others contributed to our understanding of HR variation. We present an overview of studies that describe HR variation across voxels, healthy volunteers, populations, and dietary or pharmaceutical modulations. We also describe efforts to minimize the effects of HR variation in intrasubject, group, population, and connectivity analyses and the limits of these methods.

Publication types

  • Historical Article
  • Research Support, N.I.H., Intramural
  • Review

MeSH terms

  • Brain / blood supply*
  • Brain / physiology
  • Brain Mapping / history*
  • Brain Mapping / methods
  • Cerebrovascular Circulation / physiology
  • Hemodynamics / physiology*
  • History, 20th Century
  • History, 21st Century
  • Humans
  • Image Processing, Computer-Assisted / history
  • Image Processing, Computer-Assisted / methods
  • Magnetic Resonance Imaging / history*
  • Magnetic Resonance Imaging / methods
  • Models, Neurological*