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!SeeLemieux 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.AndK.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¨C355.RegardsDavid______________________________________David Carmichael PhD MInstPSenior Research Fellow in MR PhysicsDepartment of Clinical and Experimental EpilepsyInstitute of Neurology, University College LondonCorrespondence to:Wellcome High Field MR Research LaboratoryUniversity College London12 Queen SquareLondon WC1N 3ARTel +44 (0)20 76762006Fax +44 (0)20 76762005email [log in to unmask]-----Original Message-----
From: SPM (Statistical Parametric Mapping) [mailto:[log in to unmask]] On Behalf Of Zhang Zhiqiang
Sent: 22 April 2008 08:56
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Subject: [SPM] How to eliminate the head movement related to task?Dear SPMers,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?Thank you very much!Zhiqiang Zhang,