open-discussion
open-discussion > RE: contrast
Jun 10, 2022 09:06 PM | Alex Fornito
RE: contrast
Originally posted by Selma Lugtmeijer:
Hi,
You could in principle use a [1 0] contrast to map FC in condition A and then [0 1] for condition B and then compare the two, but it will change the interpretation. In this case, the FC matrix you map for each condition will be condition A vs the implicit baseline (i.e, everything else), which is slightly different to a [1 -1] scenario, where the FC matrix captures coupling between the task-modulated component of regional signals.
Ultimately it depends on whether you think the [1 0] scenario is interpretable.
hth
A
Hi,
thank you for making this toolbox available! I have two questions:
Does there always need to be a contrast of 2 conditions? What if I want to see in 1 condition if 2 groups of subjects differ in strength of functional connectivity for certain ROI pairs?
And a more theoretical question, is creating a FC matrix for task condition 1 and 2 separately and subtracting them, the same as creating one FC matrix for the contrast 1-2?
Thanks,
Selma
thank you for making this toolbox available! I have two questions:
Does there always need to be a contrast of 2 conditions? What if I want to see in 1 condition if 2 groups of subjects differ in strength of functional connectivity for certain ROI pairs?
And a more theoretical question, is creating a FC matrix for task condition 1 and 2 separately and subtracting them, the same as creating one FC matrix for the contrast 1-2?
Thanks,
Selma
Hi,
You could in principle use a [1 0] contrast to map FC in condition A and then [0 1] for condition B and then compare the two, but it will change the interpretation. In this case, the FC matrix you map for each condition will be condition A vs the implicit baseline (i.e, everything else), which is slightly different to a [1 -1] scenario, where the FC matrix captures coupling between the task-modulated component of regional signals.
Ultimately it depends on whether you think the [1 0] scenario is interpretable.
hth
A
Threaded View
| Title | Author | Date |
|---|---|---|
| Selma Lugtmeijer | Jun 10, 2022 | |
| Alex Fornito | Jun 10, 2022 | |
| Selma Lugtmeijer | Jun 14, 2022 | |