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Hi - you are comparing two very different analyses that have several crucial differences between them, so I'm afraid it doesn't make too much sense to try to explain why they are different…..? Cheers. On 5 Sep 2011, at 08:43, Andres Roman wrote: > Hi FSL crew, > > Im doing a three group comparison using a one level three factors model. > I used the one factor four levels example as my guide to create my model. So > I have right now that EV1 fits condition C (it is the only nonzero EV during > condition D). EV2 fits A relative to this, i.e. represents A-C. The F-test > then tests for any deviation - ie any difference between the levels. I also > included demeaned age, sex and handedness as covariates. > > I am using randomise with the same parameters I used running Feat for the > same data-set only adding a mask. Here is the randomise settings I have been > using: > > > randomise -i cope1.feat/filtered_func_data.nii.gz -o > random_results_3groups_MASK-enc -d design.mat -t design.con -f design.fts -m > final_mask_WM-10mm.nii.gz -v 6 -T -V -n 100 > > After I have been running this I obtain different results compared to Feat > although I am using the same design matrix and contrasts. I wondered why > could that be? Also I have a question related to the output of randomise > when usig the -T option which is meant to carry out Threshold-Free Cluster > Enhancement. When I do this I obtain files with the following > characteristics: > > _tfce_corrp_tstat1.nii.gz > _tfce_p_tstat1.nii.gz > _tstat1.nii.gz > > I am sure the corrp_tstat files are the corrected output of my data than > then I can treshold at min 0.95 max 1 for a P<0.05. I just wanted to confirm > this and then see what the others files output is. Thank you very much for > your help as usual. > > Best wishes > > > > > -- > Andres > --------------------------------------------------------------------------- Stephen M. Smith, Professor of Biomedical Engineering Associate Director, Oxford University FMRIB Centre FMRIB, JR Hospital, Headington, Oxford OX3 9DU, UK +44 (0) 1865 222726 (fax 222717) [log in to unmask] http://www.fmrib.ox.ac.uk/~steve ---------------------------------------------------------------------------