Hi Emily, the processing stream is designed to mask out cortical regions from the volume analysis. The volume analysis is used for subcortical structures. To make sure that the same voxels are not analyzed twice, the cortical surface is masked out of the mni305 analysis. doug
ps. If you really want to see the full volume analysis, then there are some flags that will do this.
On 08/07/2013 01:15 PM, Emily Boeke wrote:
Hello everyone,
I am looking at a visual stimulus vs fixation contrast in my individual subjects' data to make sure we are seeing normal activation there. If I look at the surface data in tksurfer, I see activation in the occipital cortex, but in the mni305 analysis, there is no activation in this region.
These are the preprocess , mkanalysis, and selxavg commands I used for the surface vs. mni305:
preproc-sess -s amur_dss -df sesspar -per-run -fwhm 5 -sliceorder down -surface fsaverage lhrh -mni305-2mm -fsd cond
mkanalysis-sess -fsd cond -surface fsaverage lh -fwhm 5 -paradigm Fear_Gen_Cond.par -event-related -TR 3 -nconditions 3 -polyfit 4 -spmhrf 0 -refeventdur 6 -analysis cond.sm05.lh -per-run -nskip 4 -stc down
mkanalysis-sess -fsd cond -surface fsaverage rh -fwhm 5 -paradigm Fear_Gen_Cond.par -event-related -TR 3 -nconditions 3 -polyfit 4 -spmhrf 0 -refeventdur 6 -analysis cond.sm05.rh -per-run -nskip 4 -stc down
mkanalysis-sess -fsd cond -mni305 2 -fwhm 5 -paradigm Fear_Gen_Cond.par -event-related -TR 3 -nconditions 3 -polyfit 4 -spmhrf 0 -refeventdur 6 -analysis cond.sm05.mni305 -per-run -nskip 4 -stc down
selxavg3-sess -s amur_dss -df sesspar -analysis cond.sm.lh selxavg3-sess -s amur_dss -df sesspar -analysis cond.sm.rh selxavg3-sess -s amur_dss -df sesspar -analysis cond.sm.mni305
Why might we be seeing this activation on the surface map but not the volume one?
Thanks! Emily _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer