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help > RE: directed connectivity
Nov 29, 2021 10:11 PM | Andrew Zalesky
RE: directed connectivity
Hi Yolanda,
no - the directed version of NBS requires directed connectivity matrices.
If your matrices are directed (i.e. asymmetric), use the directed version of NBS. If your matrices are not directed (i.e. symmetric) use the usual version of the NBS.
You may be thinking that the NBS estimates directionality, but this is not the case. NBS identifies significant connections/networks for which directionality has already been inferred using (for example) Granger causality. Granger causality is not implemented in the NBS.
best wishes,
Andrew
Originally posted by Yolanda Schlumpf:
no - the directed version of NBS requires directed connectivity matrices.
If your matrices are directed (i.e. asymmetric), use the directed version of NBS. If your matrices are not directed (i.e. symmetric) use the usual version of the NBS.
You may be thinking that the NBS estimates directionality, but this is not the case. NBS identifies significant connections/networks for which directionality has already been inferred using (for example) Granger causality. Granger causality is not implemented in the NBS.
best wishes,
Andrew
Originally posted by Yolanda Schlumpf:
Dear Andrew Zalesky
I'm very much interested in running a directed connectivity analysis using the directed NBS toolbox programmed by you and Maximilian von Gellhorn. Do I understand it correctly that I can use the same (weighted) connectivity matrices I used for the original NBS analysis for the directed connectivity approach?
On which mathematical background the analysis implemented in directed NBS calculates directed networks? Granger causality?
I have a 2 (Groups; patients and controls) x 2 (Time points, T1 and T2) factorial design. I calculated connectivity matrices for both groups and both measurement points. I'm interested in the interaction effect group x time point. Can I run a t-test on the difference connectivity matrices (i.e., [Patient T2 - Patient T1] vs. [Controls T2 - Controls T1])? I know that this is possible for the original (undirected) connectivity analysis in NBS. But I'm wondering if it produces correct results in the directed connectivity analysis as well?
I would appreciate very much your support.
Kind regards,
Yolanda
I'm very much interested in running a directed connectivity analysis using the directed NBS toolbox programmed by you and Maximilian von Gellhorn. Do I understand it correctly that I can use the same (weighted) connectivity matrices I used for the original NBS analysis for the directed connectivity approach?
On which mathematical background the analysis implemented in directed NBS calculates directed networks? Granger causality?
I have a 2 (Groups; patients and controls) x 2 (Time points, T1 and T2) factorial design. I calculated connectivity matrices for both groups and both measurement points. I'm interested in the interaction effect group x time point. Can I run a t-test on the difference connectivity matrices (i.e., [Patient T2 - Patient T1] vs. [Controls T2 - Controls T1])? I know that this is possible for the original (undirected) connectivity analysis in NBS. But I'm wondering if it produces correct results in the directed connectivity analysis as well?
I would appreciate very much your support.
Kind regards,
Yolanda
Threaded View
Title | Author | Date |
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Yolanda Schlumpf | Nov 29, 2021 | |
Andrew Zalesky | Nov 29, 2021 | |
Yolanda Schlumpf | Dec 2, 2021 | |
Andrew Zalesky | Dec 3, 2021 | |
Yolanda Schlumpf | Dec 4, 2021 | |