Comparing hemodynamic models with DCM

By Klaas E. Stephan, Nikolaus Weiskopf, Peter M. Drysdale, Peter A. Robinson, Karl J. Friston. NeuroImage, 2007

458 citations recorded by the source corpus.

The classical model of blood oxygen level dependent (BOLD) responses by Buxton et al. (1998) has been very important in providing a biophysically plausible framework for explaining different aspects of hemodynamic responses. It also plays an important role in the hemodynamic forward model for dynamic causal modeling (DCM) of fMRI data. A recent study by Obata et al. (2004) linearized the BOLD signal equation and suggested a revised form for the model coefficients. In this paper, we show that the classical and revised models are special cases of a generalized model. The BOLD signal equation of this generalized model can be reduced to that of the classical Buxton model by simplifying the coefficients or can be linearized to give the Obata model. Given the importance of hemodynamic models for investigating BOLD responses and analyses of effective connectivity with DCM, the question arises which formulation is the best model for empirically measured BOLD responses. In this article, we address this question by embedding different variants of the BOLD signal equation in a well-established DCM of functional interactions among visual areas. This allows us to compare the ensuing models using Bayesian model selection. Our model comparison approach had a factorial structure, comparing eight different hemodynamic models based on (i) classical vs. revised forms for the coefficients, (ii) linear vs. non-linear output equations, and (iii) fixed vs. free parameters, ε, for region-specific ratios of intra- and extravascular signals. Using fMRI data from a group of twelve subjects, we demonstrate that the best model is a non-linear model with a revised form for the coefficients, in which ε is treated as a free parameter.

Subfields: Cognitive Neuroscience, Radiology, Nuclear Medicine and Imaging

View Paper: https://www.semanticscholar.org/paper/4984e7bebcb8d39a55ca1dd80a745e4868864906

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Cognitive Neuroscience

  1. Karl J. Friston
  2. Simon B. Eickhoff
  3. Jean Daunizeau
  4. W. D. Penny
  5. Rosalyn J. Moran
  6. Anil K. Seth
  7. Thomas E. Nichols
  8. Gereon R. Fink

In Radiology, Nuclear Medicine and Imaging

  1. Karl J. Friston
  2. Simon B. Eickhoff
  3. W. D. Penny
  4. Jean Daunizeau
  5. Thomas E. Nichols
  6. Rosalyn J. Moran
  7. Gereon R. Fink
  8. Russell A. Poldrack

Citations in the corpus