Dear members of SPM list,
is someone aware of how one can perform directional contrasts on
individual subject level after including temporal derivatives into the
model?
For the group level, I'm using Calhoun et al. (2004) / Steffener et
al. (2010) approach of 'boosting' con images with the temporal
derivatives. But besides group analysis I also need individual
activation maps for each subject. I cannot sacrifice the
information from the temporal derivatives at the individual level
because the subjects are from a special population and there are
somewhat pronounced diffrerences in the HR latencies. At the same time
I'm not satisfied with the results from the F-test incorporating both
the canonical HRF and the temporal derivaitve, since it is
bi-directional and introduces the certain amount of 'deactivation' that
we're not interested in.
The design is very simple, it's just a block-design motor task.
I even think of masking the 'deactivation' out, but hope there is still
a better way. Can someone suggest a solution, please?
Sincerely,
Ekaterina.
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