I'm interested in the correlation between a time series and the voxels
in the brain. To find out more I made a GLM
(see http://www.sal.mvm.ed.ac.uk/images/problem1.png ).
Before estimation it looks fine (I think?).
During estimation however, 6 of the 8 columns are set to zero (see
inset in bottom-left corner of the linked image). Just sessions 1 and
3 output beta images. There are no errors or warnings expressed during
estimation, and the matlab output appears ok.
- I've confirmed the number of images in each session is equal to the
number of values in the .txt regressor files.
- I've tried adding conditions to each session (just a single event
near the start of each session) to see if it's the lack of conditions
that's upsetting SPM. (this didn't make any difference).
- I've rebuilt the design matrix from scratch by hand, using the
interface, but that didn't make any difference.
Looking forward to any suggestions!
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