Hello, i have a problem with PPI-analysis
Group of 18 right handed subjects with healthy vision performed braille reading tactile tasks in MRI. Braille reading was than contrasted with control task. After tactile training the fMRI task was repeated.
Im planning to do the PPI analysis on those data sets. I want to see the relations between various cortical regions. I want to see if the training changed the relations between the structures (ROI’s). I just finished extracting ROIs from individual subjects after the training from t-contrast defined as signs minus control task.
Is that correct to extract VOI’s by eigenvariate function from contrast task-control or task and control separately?
Does it make sense to treat "before" and “after” the training as psychological (PPI) variable?
The most important one: - I have extracted (using eigenvariate) VOI’s without adjusting the data to f contrast? Is it wrong? i couldn’t find the reason why to do that? I chose “don’t adjust” option and I’m not sure what are the exact consequences of that choice. can You help me by explaining it or refer me to some other source? What exactly happens when i choose various types of adjustments?
Do You have any tips or suggestions on how to perform an analysis on the data i described?
I would be grateful for any help
Jan Stasinski
Warsaw
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