Dear SPMers,
I am a beginner in SPM, so I would appreciate your advice.
I am running a multivariate analysis on distinguishing two conditions on a single-subjects level. For the purpose of multivariate analysis I do not normalize the data. For the analysis, i am interested in grey matter voxels only. So I need a grey matter image that would be coregistered with my functional images, to use that as a mask. What is an optimal sequence of operations to get there? I can 1) first segment the structural image, and then coregister (estimate and reslice) the grey matter image with the functional mean or 2) do coregister:estimate prior to segmentation, then segmentation, and then coregister:reslice after the segmentation. Or 3) I can first segment the structural image, then coregister:estimate using the corrected structural as a source, referenced to the functional mean, and introducing the same manipulation in the grey matter image by selecting it as "other images".
Which way do you think is most appropriate? Or maybe there is a better way which I don't see, being a beginner in fMRI and SPM.
Thank you very much in advance,
Best,
Irina
|