Dear FSL community,
I have 2 questions regarding FEAT analysis.
a) I have a situation where in study of 12 subjects I want to compare 2
modeling strategies (with and without single trial psychophysiological
information). When modeled entirely seperately using the quantitative
information (3rd column in 3-column log file containing physiological data
instead of fixed stimulus intensity) does not give "more" activation in any
of the 12 subjects. However, in the group level analysis, all of a sudden
the model containing psychophysiological information gives more (also
reasonable) activation, but only in the mixed effects flame.
How is that possible?
b) I want to compare these 2 models more directly, asking which one is more
informative or even, what is the quantitative information adding to the
"regular" model. What is the way to go? Contrasting seems to give
unreasonable results. Orthogonalisation? If itīs orthogonalisation how
should it be set up? Again: I have to identical time courses with and
without quantitative information in the 3 column of the custom logfile.
Thanks!
Arian
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