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Hi Matt - I am probably missing something - where do you see the averaged time course and num voxels in the output of a low level analysis? The peak z-stat co-ordinate should be within the pre-threshold mask. For FEATquery it will depend on whether you run it on the thresh_zstats or non-thresholded images. You're probably aware - a cluster-based threshold of 0 in FEAT is meaningless. But it will not include all voxels, as many will have negative values. Cheers, Eugene -- On 10 December 2012 21:53, Matthew Ward <[log in to unmask]> wrote: > I meant to explain why I'm asking. If I run a low-level FEAT analysis on > a 4D time series with cluster-based threshold set to 0 without a mask, the > average time course of the contrast is based on ~91K voxels. However, if I > add a small, pre-threshold mask, the resultant average time course is base > on ~98K voxels. So, if the average time course was based solely on voxels > within the mask, I would have expected only a small percentage of the ~91K > to contribute to the time course. Instead, the number of voxels the > average time course included INCREASED with the application of a mask. Any > clarification on why this is happening would be greatly appreciated. > > Matt > >