Mixed-effects and fMRI studies

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • K. J. Friston - , University College London (Author)
  • K. E. Stephan - , University College London (Author)
  • T. E. Lund - , University of Copenhagen (Author)
  • A. Morcom - , University of Cambridge (Author)
  • S. Kiebel - , Chair of cognitive computational neuroscience, University College London (Author)

Abstract

This note concerns mixed-effect (MFX) analyses in multisession functional magnetic resonance imaging (fMRI) studies. It clarifies the relationship between mixed-effect analyses and the two-stage "summary statistics" procedure (Holmes, A.P., Friston, K.J., 1998. Generalisability, random effects and population inference. NeuroImage 7, S754) that has been adopted widely for analyses of fMRI data at the group level. We describe a simple procedure, based on restricted maximum likelihood (ReML) estimates of covariance components, that enables full mixed-effects analyses in the context of statistical parametric mapping. Using this procedure, we compare the results of a full mixed-effects analysis with those obtained from the simpler two-stage procedure and comment on the situations when the two approaches may give different results.

Details

Original languageEnglish
Pages (from-to)244-252
Number of pages9
JournalNeuroImage
Volume24
Issue number1
Publication statusPublished - Jan 2005
Peer-reviewedYes

External IDs

PubMed 15588616

Keywords

ASJC Scopus subject areas

Keywords

  • EM, Hierarchical observation models, Inference, Mixed-effects analysis, Random-effects analysis, ReML