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help > RE: import condition/session specific values
Mar 8, 2016 07:03 PM | Alfonso Nieto-Castanon - Boston University
RE: import condition/session specific values
Hi Pauline,
Yes, for ROI-to-ROI analyses you may simpy enter in your 'between-subjects' contrast [1 0;0 1] (or eye(2)), and the same in your 'between-conditions' contrast, and that will display four values (the z-scores for each group and for each condition). If you prefer to see, for example, the differences in connectivity post vs. pre separately in each subject group you would do that instead by entering in your 'between-subjects' contrast [1 0;0 1] (to see each group separately), and in your 'between-conditions' contrast [-1 1] (to see the post- vs. pre- difference in connectivity).
The same applies to seed-to-voxel analyses. The only trick there is that you have to add one additional step to define the cluster(s) that you may want to extract your connectivity values from. So, for example, if you are interested in the group by condition interaction (e.g. [-1 1] for both the betwee-subjects and between-conditions contrasts), you would first run those analyses, define in the seed-to-voxel the thresholds and click on 'export mask' to define a ROI-file mask with those suprathreshold clusters of interest. If you then want to then look at the connectivity values separately for each condition and group within those clusters, you would then create a new second-level analysis now entering [1 0;0 1] in both the 'between-subjects' and 'between-conditions' contrast fields, and then click on the 'extract values' or 'display values' button, and there you would select the option that says something like "extract from different clusters (select ROI file)" and there select the ROI file that you created in the step above. That will display (or extract) the Fisher transformed correlation coefficients separately for each group and for each condition within the originally-defined suprathreshold clusters.
Let me know if this clarifies
Best
Alfonso
Originally posted by Pauline Favre:
Yes, for ROI-to-ROI analyses you may simpy enter in your 'between-subjects' contrast [1 0;0 1] (or eye(2)), and the same in your 'between-conditions' contrast, and that will display four values (the z-scores for each group and for each condition). If you prefer to see, for example, the differences in connectivity post vs. pre separately in each subject group you would do that instead by entering in your 'between-subjects' contrast [1 0;0 1] (to see each group separately), and in your 'between-conditions' contrast [-1 1] (to see the post- vs. pre- difference in connectivity).
The same applies to seed-to-voxel analyses. The only trick there is that you have to add one additional step to define the cluster(s) that you may want to extract your connectivity values from. So, for example, if you are interested in the group by condition interaction (e.g. [-1 1] for both the betwee-subjects and between-conditions contrasts), you would first run those analyses, define in the seed-to-voxel the thresholds and click on 'export mask' to define a ROI-file mask with those suprathreshold clusters of interest. If you then want to then look at the connectivity values separately for each condition and group within those clusters, you would then create a new second-level analysis now entering [1 0;0 1] in both the 'between-subjects' and 'between-conditions' contrast fields, and then click on the 'extract values' or 'display values' button, and there you would select the option that says something like "extract from different clusters (select ROI file)" and there select the ROI file that you created in the step above. That will display (or extract) the Fisher transformed correlation coefficients separately for each group and for each condition within the originally-defined suprathreshold clusters.
Let me know if this clarifies
Best
Alfonso
Originally posted by Pauline Favre:
Dear Alfonso and experts,
I'm running a mixed between-within-subjects design (2 groups scanned two times). I set up two groups in the subjects-effects field and two sessions in the conditions-effects field.
Everything works well except that I can't figure out how to extract the session specific connectivity results.
e.g., when assessing the effect pre vs post in the patients group, the import values function (seed-to-voxel result explorer) gives only one value per patient. I guess this is the difference of the z-scores pre vs post?
Is there any way to extract (and plot) directly the session/condition specific z-scores (without going through the connectivity matrix of each subject)?
Thanks for your help,
Best,
Pauline
I'm running a mixed between-within-subjects design (2 groups scanned two times). I set up two groups in the subjects-effects field and two sessions in the conditions-effects field.
Everything works well except that I can't figure out how to extract the session specific connectivity results.
e.g., when assessing the effect pre vs post in the patients group, the import values function (seed-to-voxel result explorer) gives only one value per patient. I guess this is the difference of the z-scores pre vs post?
Is there any way to extract (and plot) directly the session/condition specific z-scores (without going through the connectivity matrix of each subject)?
Thanks for your help,
Best,
Pauline
Threaded View
| Title | Author | Date |
|---|---|---|
| Pauline Favre | Mar 8, 2016 | |
| Alfonso Nieto-Castanon | Mar 8, 2016 | |
| Pauline Favre | Mar 8, 2016 | |
| Alfonso Nieto-Castanon | Mar 9, 2016 | |