Dear SPM experts,
we recently encountered a problem with our data from simultaneous EEG-fMRI measurements when co –registering our EPI’s to the subjects individual MPRAGE. Even though the co-registration procedure seems to work judging from SPM’s “normalised mutual information coregistration” output file, we find activity outside the brain if we map the activation onto the subjects MPRAGE. If we set the p-value to 1 (threshold = 0) the fully activated brain is shifted away from the structural image. This is not the case if we map the subject’s brain ac-tivity onto the single_subj_T1.nii template.
Researchers from other labs who also conducted EEG-fMRI co-measurements reported the same problem to us.
We also tried to fix the problem with an approach suggested by John Ashburner, using images gained from the segmentation procedure. Here’s the link:
But unfortunately it didn’t work, at least not for our data.
Are there any suggestions how to deal with this problem?