User specified regressors are not convolved with the HRF, they are used as entered.
-Mike
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From: SPM (Statistical Parametric Mapping) <
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Sent: Monday, December 19, 2016 4:06 PM
To:
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Subject: [SPM] censor motion scans at first level: some questions
Hi!
I am using SPM8, and am interested in censoring high motion scans as suggested in
Siegel, et al. “Statistical Improvements in Functional Magnetic Resonance Imaging Analyses Produced by Censoring High-Motion Data Points.” Human Brain Mapping 35, no. 5 (May 2014): 1981–96.
I have seen it suggested here on this listserv that an effective way to do this would be to incorporate these as regressors of no interest in the design matrix. I am a little confused, however, as doing so would convolve these with the hrf (correct?), which does not seem ideal, as the changes in signal are not haemodynamic in origin. I would be grateful if someone might clarify, for a SPM novice, whether my concerns are on the mark, and what the best approach would be (other than say using ArtRepair, which I understand interpolates scans rather than drop them).
Thanks!
Jim
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