Dear Zhang,
You should use realignment parameters and possibly scan nulling as extra regressors in your GLM which will remove false
positives from your results. If movement always occurs with your task then you cannot separate the motion form the response and you need new data!
See
Lemieux L, Salek-Haddadi A, Lund TE, Laufs H, Carmichael D. Modelling large motion events in fMRI studies of patients with epilepsy.Magn Reson Imaging. 2007 Jul;25(6):894-901.
And
K.J. Friston, S. Williams, R. Howard, R.S.J. Frackowiack and R. Turner, Movement-related effects in fMRI time-series, Magn Reson Med 35 (1996), pp. 346–355.
Regards
David
______________________________________
David Carmichael PhD MInstP
Senior Research Fellow in MR Physics
Department of Clinical and Experimental Epilepsy
Institute of
Neurology, University College London
Correspondence to:
Wellcome High Field MR Research Laboratory
University College London
12 Queen Square
London WC1N 3AR
Tel +44 (0)20 76762006
Fax +44 (0)20 76762005
-----Original Message-----
From: SPM (Statistical Parametric Mapping) [mailto:[log in to unmask]] On Behalf Of Zhang Zhiqiang
Sent: 22 April 2008 08:56
To: [log in to unmask]
Subject: [SPM] How to eliminate the head movement related to task?
I have a special case whose fMRI data is found having task-related movements during scan. the maximal extent is 2.5mm. I'd like to know how to eliminate the false effect to result of this movement ? is there any paper focusing on this?
