Chapter

Preparing fMRI data for statistical analysis

Stephen M. Smith

in Functional Magnetic Resonance Imaging

Published in print November 2001 | ISBN: 9780192630711
Published online March 2012 | e-ISBN: 9780191724770 | DOI: http://dx.doi.org/10.1093/acprof:oso/9780192630711.003.0012
Preparing fMRI data for statistical analysis

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This chapter describes the various preprocessing steps necessary to take raw data from the scanner and prepare it for the ‘heart’ of functional magnetic resonance imaging analysis, namely statistical analysis. These preprocessing steps take the raw MR data, convert it into images that actually look like brains, then reduce unwanted noise of various types and precondition the data in order to aid the later statistics. The chapter also discusses how it is much easier to ‘automate’ the preprocessing steps than the statistical analysis because optimal tuning of preprocessing algorithms is less dependent on the details of any particular experiment than is the case with later statistics. It discusses the reasons for applying spatial filtering as a preprocessing step and results clearly show the blurring of activation areas as spatial filtering extent increases, even causing ‘activation’ outside of the brain.

Keywords: preprocessing algorithms; statistical analysis; spatial filtering; tuning; scanner; blurring; noise reduction

Chapter.  5750 words.  Illustrated.

Subjects: Neuroscience

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