Dear SPM experts,
I would like to analyze my fMRI data using PPI and have a question
concerning
the definition of VOIs.
My design consisted of two conditions (A,B) which both consisted of two
subphases (1,2).
In my results (2nd level), I obtain a condition x subphase interaction.
I would like
to conduct PPI using a seed region that shows up in this interaction
contrast.
My question concerns the definition of VOIs for this seed region on the
single
subject level: Do I define the VOI for each subject on the first level
interaction
contrast? Or do I use other 1st level contrasts (e.g., Condition A >
Condition B
for subphase 1; or Condition A > Conditon B for subphase 2...) for the
definition
of the VOIs?
Thank you very much in advance for your help.
Julia
--
Julia Weiler
Ruhr-University Bochum
Inst. of Cognitive Neuroscience
Department of Neuropsychology
GAFO 05/606
Phone: +49-234-3223574
Fax: +49-234-3214622
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