[color=#000000]Dear Alfonso,[/color]
[color=#000000]thank you, this is very helpful information and a welcome suggestion for the first question so that I can present my results a bit more reviewer-friendly. I enjoy the use of CONN and am grateful for the quick feedback on the forum.[/color]
[color=#000000]Helene[/color]
[i]Originally posted by Alfonso Nieto-Castanon:[/i][quote][color=#000000]Dear Helene,[/color]
[color=#000000]Regarding (1) yes, you are exactly right that a Bonferroni correction of 6 (3 within-/between- network comparisons and 2-tailed) would suffice for these analyses (that is the number of multiple tests that are being evaluated by that script). If you prefer, you could also (perhaps a bit more standard) first convert the three uncorrected p-values output by the script into two-sided p-values (using a [b]p2 = 2*min(p,1-p)[/b] formula), and then apply FDR across those multiple tests (using a [b]P = conn_fdr(p2)[/b] command). That should be similarly valid and a bit less conservative than Bonferroni. [/color]
[color=#000000]Regarding (2), the former computation is used (i.e. the script averages the ROI-to-ROI connectivity values between all ROI pairs with ROI1 in set1 and ROI2 in set2)[/color]
[color=#000000]Hope this helps, and my apologies that this conn_withinbetween* script/functionality is still undocumented, I will eventually get around to making this part of the standard set of ROI/network analyses in CONN[/color]
[color=#000000]Alfonso[/color]
[i]Originally posted by Helene Veenstra:[/i][quote]Dear Alfonso,
Reviving an older thread as I am using this code line for my analyses, as I was interested in network connectivity changes related to covariates and groups. I have a couple of questions.
1) since this analysis uses (uncorrected) two-tailed p-values; however draws from a small pool of regions to test, would it be appropriate to consider the results being adequately corrected with a Bonferroni correction for number of tests, and appropriate choice of number of tails?
Example: I investigate several hypotheses (different covariates/group comparisons) for the connectivity within two networks (SN, DMN) and the connectivity between those two. To obtain a p-value <0.05 per hypothesis, I use a corrected p-value with a Bonferroni correction of 6 (p<0.0083) based on 3 network (SN, DMN, SN-DMN) tests * 2 for two-tailed.
2) as you explained this gives an average over all ROI connections within each chosen network. But how exactly is the between-network value calculated? As an average of every possible ROI (group1) to ROI (group2) connection? Or a calculated connectivity of the averaged connectivity over all ROIs within each group?[/quote][/quote]