Hi all,
We performed a mixed effects group comparison on fMRI task data; a patient group showed hypoactivity in a 50-voxel cluster (Z=3.1 cluster corrected) within an overall task effect mask relative to controls.
We than treated half the patient group and compared it to the untreated half after seven weeks of waitlist or treatment using a fixed-effects model with an interaction between time and group and looked within the 50-voxel mask of the initial group difference using voxel-corrected statistics at p < .05.
A reviewer is questioning our use of voxel-level statistics and this threshold, he would like to see a reference to a study employing similar methodology. When using voxel-level statistics within a mask, p < .05 is not an overly liberal threshold to use, right? Could someone provide a good ref?
Cheers,
Diederick
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