Set the threshold to -Inf. This will include all voxels, and use explicit mask to restrict computation to the brain tissue.
Stan
On Feb 8, 2014, at 12:44 PM, Lesley Sand <[log in to unmask]> wrote:
> Hello,
>
> I have 20 subjects from a study using a 32-channel head coil (Siemens Trio) and have questions concerning masking. I have run the analysis in SPM12b.
>
> When I run the subjects without an explicit mask (using the implicit masking threshold default of .8) the group mask has some dropout. In order to correct this, I applied an explicit mask from the FieldMap toolbox, brainmask.nii. However, the same signal dropout remains. I have changed the threshold (trying many iterations between -inf and .8) and while I obtain better coverage (at about .4), it is still not ideal.
>
> Is there a different mask I could apply, or a different approach all together that you would suggest?
>
> Thank you in advance,
> Lesley Sand
>
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