Dear List,
to deal with the problems regarding correlations between global brain signal
and the task in
fMRI experiments we use the tool rd_taskcorr provided by Kalina Christoff to
compute
the significance of those correlations.
If we have very simple experiments with an ABABAB design, we can just skip
global scaling
if we detect a significant correlation.
Now we analyze data of an experiment with 3 different stimulation conditions
and corresponding
three different rest conditions. What should be done if there is a
correlation between global signal
and e.g. Rest3, but no significant correlation for Stim1-3 and Rest1-2 ?
Should we compute some contrasts with global scaling and other contrasts
without ?
Thanks for your opinions
Thomas Stephan
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Thomas Stephan Email: [log in to unmask]
Klinikum Grosshadern
Neurologisches Forschungshaus
Marchioninistr. 23 Fon: +49 089 / 7095-4819
81377 Muenchen Fax: +49 089 / 7095-4801
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