Doug,
From what I understand, spmhrf 0 calculates the amplitude of the the hrf
and spmhrf 1 derives the amplitude and the latency (which I thought was the 2nd derivative). I am not sure how the latency calculation contributes to the model but my contrast maps using spmhrf 1 are slightly different from those generated using spmhrf 0. Here are the parts of the processing stream relevant to the ROI analysis I used:
mkanalysis-sess.new -analysis retrievalSPMHRF1 -TR 2.5 -paradigm paradigmmacro -designtype event-related -nconditions 3 -spmhrf 1 -funcstem fmcsm -taumax 30
selxavg-sess -a retrievalSPMHRF1 -sf sessidall3cond -df sesspar
mri_annotation2label --subject SM2C1_autoreconall --hemi lh --outdir SM2C1_autoreconall/labels
func2roi-sess -roidef L10noFmask -a retrievalSPMHRF1 -sesslabel lh.parsorbitalis -sf sessidall3cond -df sesspar
roisummary-sess -sumfile L10noFmask -a retrievalSPMHRF1 -sf sessidall3cond -df sesspar
I included an attachment of the roisummary that I receive after this final step. I was only expecting 3 values, a value for each condition for each subject, but I am not sure what the other three are. I think they are related to the latency derivative but I don't know for sure nor do I know which 3 correspond to the amplitude. Thanks, Cameron
Hard to say without knowing more about what's going on (which is why it's good to err on the side of more detail). Did you use a derivative?
Cameron Ellis wrote:
Hello, I am trying to interpret the results I receive from roisummary-sess. My analysis models the hrf using spmhrf 1 and I have 3 conditions. However, roisummary-sess generates 6 condition values for each subject. Does this have something to do with the fact that spmhrf 1 calculates both amplitude and latency and is therefore giving me 2 numbers for each condition? If so, which numbers correspond to which calculation? Help from anyone is much appreciated... Thanks, Cameron _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
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