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Hum Brain Mapp. 2014 May;35(5):1981-96. doi: 10.1002/hbm.22307. Epub 2013 Jul 17.

Statistical improvements in functional magnetic resonance imaging analyses produced by censoring high-motion data points.

Author information

1
Department of Neurology, Washington University School of Medicine, St. Louis, Missouri.

Abstract

Subject motion degrades the quality of task functional magnetic resonance imaging (fMRI) data. Here, we test two classes of methods to counteract the effects of motion in task fMRI data: (1) a variety of motion regressions and (2) motion censoring ("motion scrubbing"). In motion regression, various regressors based on realignment estimates were included as nuisance regressors in general linear model (GLM) estimation. In motion censoring, volumes in which head motion exceeded a threshold were withheld from GLM estimation. The effects of each method were explored in several task fMRI data sets and compared using indicators of data quality and signal-to-noise ratio. Motion censoring decreased variance in parameter estimates within- and across-subjects, reduced residual error in GLM estimation, and increased the magnitude of statistical effects. Motion censoring performed better than all forms of motion regression and also performed well across a variety of parameter spaces, in GLMs with assumed or unassumed response shapes. We conclude that motion censoring improves the quality of task fMRI data and can be a valuable processing step in studies involving populations with even mild amounts of head movement.

KEYWORDS:

GLM; data quality; fMRI; general linear model; head movement; motion; noise; scrubbing; task

PMID:
23861343
PMCID:
PMC3895106
DOI:
10.1002/hbm.22307
[Indexed for MEDLINE]
Free PMC Article

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