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Date: Wed, 06 Sep 2000 15:03:40 +1000
Subject: event-related design: sparse method
From: Greig de Zubicaray <[log in to unmask]>
To: SPM <[log in to unmask]>
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Dear SPMers,
I have a question regarding analysis of a sparse event-related fMRI
experiment similar to that described by Elliott et al. (1999). MRM,
41,1230-5, using a 15 s TR. Trials are from 3 conditions and run in
randomised order.
Modelling event-related fMRI experiments in SPM99 requires the data to be
convolved with an HRF basis set, although with the sparse scanning method
this should be avoided. Is there a work-around for this? Are there any
reasons why this shouldn't be modelled as a block-design fMRI experiment in
SPM99, with each block consisting of a single trial/scan? This way I can
specify that an HRF isn't needed (ditto for low pass filter). Alternatively,
can it be modelled in the PET toolkit? Although I guess I cannot include a
high-pass filter that way.
thanks,
Greig de Zubicaray
--
Centre for Magnetic Resonance
The University of Queensland
Brisbane, QLD 4072
AUSTRALIA
Tel: +61 (0) 7 3365 4250
Fax: +61 (0) 7 3365 3833
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