Re: [Freesurfer] Extracting fMRI time course and computing correlations among them

2010-07-19 Thread Douglas N Greve
mapping the time courses to the average subject does not solve this problem, it just hides it. I'm not sure why this would be of a concern anyway. There might be a tiny difference in the expected variance for each subject, but, unless the region is very small, the differences won't amount for

Re: [Freesurfer] Extracting fMRI time course and computing correlations among them

2010-07-19 Thread liang wang
Dear Doug, Thanks. According to your suggestions, I would extract fmri time course from an individual paracellation with subcortical regions (e.g. caudate, thalamus...). Would you like to help me to make sure whether the following commands are correct. Here the filtered_fun_data.nii.gz did not be

Re: [Freesurfer] Extracting fMRI time course and computing correlations among them

2010-07-19 Thread Douglas N Greve
That looks right, though mri_segstats might want a summary file. If so , just added --sum junk doug liang wang wrote: Dear Doug, Thanks. According to your suggestions, I would extract fmri time course from an individual paracellation with subcortical regions (e.g. caudate, thalamus...).

Re: [Freesurfer] Extracting fMRI time course and computing correlations among them

2010-07-18 Thread Doug Greve
definitely use the individuals. Use mri_vol2surf to convert the motion corrected (and otherwise unsmoothed) fmri time courses to the surface. Then use mri_segstats with the --avgwf and --annot options to compute the mean time course over the parcellations. doug On Sat, 17 Jul 2010, liang

Re: [Freesurfer] Extracting fMRI time course and computing correlations among them

2010-07-18 Thread liang wang
Dear Doug, Thanks for your comments. However, I am worried about the different number of voxels within each parcellation between subjects, if extracting fmri time course from individual parcellation result. Also, I am using the following combined commands to carry out the steps. Do you think

[Freesurfer] Extracting fMRI time course and computing correlations among them

2010-07-17 Thread liang wang
Hi, Does anyone know one of studies which uses the parcellations (aparc or aparc.a2009s) Freesurfer provides to extract fMRI time course from each subject's fMRI data. Reading the instructions in Freesurfer Wiki, I know how to do that. However, I am not sure whether I should use the parcellations