Hi,
Backround: I am running a fixed effects group analysis with fsaverage
(mne305) as the target brain, and merging the activations across subjects
on the spherical surface. The individual functional sessions have been
co-registered to the individuals' structural brain reconstruction (i.e.
the register.dat file inside the bold directory links the functional and
structural data within subjects only).
Problem: I am not sure how to set the group analysis func2sph-sess and
paint-sess "target brain" parameters correctly.
Version and environment: I am using the current Martinos Center FreeSurfer
standard installation (vs. >3) under nmr-std-env and all the structural
reconstructions are new as well.
Outline of the analysis (list of commands):
preprocessing
mkanalysis-sess.new
selxavg-sess
mkcontrast-sess
stxgrinder-sess
func2sph-sess <-
sphsmooth-sess
isxavg-fe-sess
stxgrinder-sess
paint-sess <-
Specific question (with possible answers):
*** 1 *** Should I set the target brain already at func2sph-sess:
func2sph-sess -analysis XXX -sf sessid -df sesspar -trgsubject
fsaverage
(if the -trgsubject setting is omitted, then the target appears be the
default = ico order 7)
*** 2 *** Or is it sufficient (if I ignore the -trgsubject parameter
above) to set:
paint-sess -analysis XXX -contrast YYY -subject fsaverage -space sph
-isxavg fixed -s fegroup -df group.sesspar
(here fegroup = the folder where the fixed effects analysis is stored, set
at isxavg-fe-sess -s fegroup)
*** 3 *** Or must/should I do both 1 and 2 of the above.
I am using surf-sess/tksurfer to view the results and set -subject
fsaverage even there.
I get results that look reasonable either way. I just wonder what is the
difference between the methods, and if either method is unambiguously
correct.
Thanks,
Tommi
---
Tommi Raij, M.D., Ph.D.
MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging
Bldg 149, 13th St
Charlestown, MA 02129
U.S.A.