Campus Units

Statistics

Document Type

Article

Publication Version

Accepted Manuscript

Publication Date

12-2013

Journal or Book Title

Stat

Volume

2

Issue

1

First Page

303

Last Page

316

DOI

10.1002/sta4.34

Abstract

It is well known that Gaussian modelling of functional magnetic resonance imaging (fMRI) magnitude time-course data, which are truly Rice distributed, constitutes an approximation, especially at low signal-to-noise ratios (SNRs). Based on this fact, previous work has argued that Rice-based activation tests show superior performance over their Gaussian-based counterparts at low SNRs and should be preferred in spite of the attendant additional computational and estimation burden. Here, we revisit these past studies and, after identifying and removing their underlying limiting assumptions and approximations, provide a more comprehensive comparison. Our experimental evaluations using Receiver Operating Characteristic (ROC) curve methodology show that tests derived using Ricean modelling are substantially superior over the Gaussian-based activation tests only for SNRs below 0.6, that is, SNR values far lower than those encountered in fMRI as currently practiced

Comments

This is the peer reviewed version of the following article: Stat 2 (2013): 303, doi: 10.1002/sta4.34, which has been published in final form at http://dx.doi.org/10.1002/sta4.34. This article may be used for non-commerical purposes in accordance with Wiley Terms and Conditions for self-archiving

Copyright Owner

John Wiley & Sons, Ltd.

Language

en

File Format

application/pdf

Published Version

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