Change point estimation in multi-subject fMRI studies

Lucy F. Robinson, Tor D. Wager, Martin A. Lindquist

Research output: Contribution to journalArticlepeer-review

Abstract

Most statistical analyses of fMRI data assume that the nature, timing and duration of the psychological processes being studied are known. However, in many areas of psychological inquiry, it is hard to specify this information a priori. Examples include studies of drug uptake, emotional states or experiments with a sustained stimulus. In this paper we assume that the timing of a subject's activation onset and duration are random variables drawn from unknown population distributions. We propose a technique for estimating these distributions assuming no functional form, and allowing for the possibility that some subjects may show no response. We illustrate how these distributions can be used to approximate the probability that a voxel/region is activated as a function of time. Further a procedure is discussed that uses a hidden Markov random field model to cluster voxels based on characteristics of their onset, duration, and anatomical location. These methods are applied to an fMRI study (n = 24) of state anxiety, and are well suited for investigating individual differences in state-related changes in fMRI activity and other measures.

Original languageEnglish (US)
Pages (from-to)1581-1592
Number of pages12
JournalNeuroImage
Volume49
Issue number2
DOIs
StatePublished - Jan 15 2010
Externally publishedYes

Keywords

  • Change-point
  • Density estimation
  • Hidden Markov random field model
  • State-related changes
  • Statistical analysis
  • fMRI

ASJC Scopus subject areas

  • Neurology
  • Cognitive Neuroscience

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