general_compute_group_bold_stats#

qx_mri.general.general_compute_group_bold_stats(flist, tfile, stats, inmask, ignore)#

general_compute_group_bold_stats(flist, tfile, stats, inmask, ignore)

A command for extraction of image statistics over the whole group.

Parameters

--flist (str):

Path to a sessions list file.

--tfile (str, default ''):

The file root to save the results to.

--stats (str, default 'sd'):

A cell array or a comma separated string specifying, which statistics to compute.

--inmask (int, default 5):

A mask of frames to exclude or an event string specifying which frames to use.

--ignore (str, default 'no'):

Do we omit frames to be ignored:

'no': do not ignore any additional frames
'fidl': ignore frames as marked in .fidl file
'<col>': the column in ∗_scrub.txt file that matches bold file to be used for ignore mask.

Notes

The function computes for each session the specified image statistics across the BOLD image, using the nimage img_stats method. Results are saved for each computed statistics in a separate file with one volume for each session with order of volumes matching the order in which the sessions are listed in the flist file. The root of the files in which the results are saved is specified in tfile. If not specified (i.e. left empty) the root will be the root of the flist.

The function is flexible in specifying what frames to use and/or exclude. The inmask parameter can specify either a mask of frames to exclude for each session, or it can specify an eventstring to be used with a per-session fidl file. If an eventstring is specifed, then the list file (flist) needs to also list a fidl file for each session. The eventstring will then be used to create a regressor matrix using general_create_task_regressors function, and each frame for which there is a non-zero value in any of the regressor columns will be included in the computation of statistics. As an example, if the statistics are to be computed across the 3rd and 4th frames of each 'neutral' and 'negative' events specified in the fidl file, then the eventstring would be:

'negative:block:3:4|neutral:block:3:4'

Additionally, the ignore parameter specifies which frames to exclude based on image scrubbing information. If the information is to be taken out of a .scrub file then the name of the relevant column needs to be specified in the ignore parameter. If the ignore parameter is set to 'fidl' then the ignore frames in the fidl file will be used.

Examples

To compute mean and standard variation and exclude the first 5 frames and the frames marked bad using udvarsme criterion, use:

qunex general_compute_group_bold_stats \
    --flist='scz-wm.list' \
    --tfile='[]' \
    --stats='m, sd' \
    --inmask=5 \
    --ignore='udvarsme'

To compute the mean and standard variation for all negative trials (frames 3 & 4), and use ignore information in fidl file, use:

qunex general_compute_group_bold_stats \
    --flist='scz-wm.list' \
    --tfile='[]' \
    --stats='m, sd' \
    --inmask='negative:block:3:4' \
    --ignore='fidl'

QuNex documentation

general_compute_group_bold_stats

general_compute_group_bold_stats#