I am preparing to run a PPI analysis using the gppi toolbox and I have a few questions to make sure I am doing it correctly. 1) VOI & extraction: Is the VOI file specified an ROI mask or is it the output of the Eigenvariate/VOI step in SPM? Does the gppi toolbox extract VOI info? 2) CompContrast & contrasts: I am unclear what this is estimating. Will this create a new SPM.mat file? Should the output of this step, if estimating, be put in a new folder. 3) weighting: I have a mixed block-event design. The events are less than 1 TR (~2s event &2.5s TR) while the blocks are 120sec. Can I specify the weight of the block as 100 or 120? How do I specify different weights? For example if I have 3 event conditions and 2 block is this how I would specify it?: weight = { 0 0 0 100 100} ? Thanks Pamela