help
help > RE: Mixed AN(C)OVA Models
Oct 31, 2013 01:10 AM | Alfonso Nieto-Castanon - Boston University
RE: Mixed AN(C)OVA Models
Hi Emanuele,
Yes, the three subject groups can be defined in the 'Setup->Covariates->Second-level' tab (e.g. creating three covariates, on for each group of subjects, and each covariate simply containing 1/0's identifying the subjects in that group), and the three time-points can be defined in the 'Setup->Conditions' tab (e.g. creating three conditions, one for each time-point, associating each condition with the corresponding session number)
In general, for any mixed within- between- subject model, within-subject effects are defined as 'conditions' and between-subject effects are defined as 'second-level covariates'. After running the analyses, in the 'second-level results' tab you will be able to select any combination of within- and between- subject effects and define an appropriate univariate or multivariate contrast to test your effects of interest (e.g. if you want to look at the interaction of session- by group- differences, you could select all three conditions and enter a 'between-condition' contrast of [1 -1 0; 0 1 -1] and select all three groups and enter a 'between-subjects' contrast of [1 -1 0; 0 1 -1]; for this example ROI-level analyses will use a multivariate Wilks' lambda test and voxel-level analyses will use an F-test combined with ReML estimation of covariance components)
Hope this helps
Alfonso
Originally posted by Emanuele Pravata':
Yes, the three subject groups can be defined in the 'Setup->Covariates->Second-level' tab (e.g. creating three covariates, on for each group of subjects, and each covariate simply containing 1/0's identifying the subjects in that group), and the three time-points can be defined in the 'Setup->Conditions' tab (e.g. creating three conditions, one for each time-point, associating each condition with the corresponding session number)
In general, for any mixed within- between- subject model, within-subject effects are defined as 'conditions' and between-subject effects are defined as 'second-level covariates'. After running the analyses, in the 'second-level results' tab you will be able to select any combination of within- and between- subject effects and define an appropriate univariate or multivariate contrast to test your effects of interest (e.g. if you want to look at the interaction of session- by group- differences, you could select all three conditions and enter a 'between-condition' contrast of [1 -1 0; 0 1 -1] and select all three groups and enter a 'between-subjects' contrast of [1 -1 0; 0 1 -1]; for this example ROI-level analyses will use a multivariate Wilks' lambda test and voxel-level analyses will use an F-test combined with ReML estimation of covariance components)
Hope this helps
Alfonso
Originally posted by Emanuele Pravata':
Hi All,
I need to test the effect of time on a longitudinal FC-MRI dataset composed of 3 sessions, and 3 groups, and to correct for a Covariate.
Is it possible to apply to CONN a model with 3 groups and 3 time-points?
Thank you!
I need to test the effect of time on a longitudinal FC-MRI dataset composed of 3 sessions, and 3 groups, and to correct for a Covariate.
Is it possible to apply to CONN a model with 3 groups and 3 time-points?
Thank you!
Threaded View
| Title | Author | Date |
|---|---|---|
| Emanuele Pravata' | Oct 17, 2013 | |
| Alfonso Nieto-Castanon | Oct 31, 2013 | |
| Emanuele Pravata' | Dec 10, 2013 | |
| Alfonso Nieto-Castanon | Dec 11, 2013 | |
| Lihong Wang | Mar 31, 2025 | |
| Lihong Wang | Apr 8, 2025 | |
| Alfonso Nieto-Castanon | Apr 8, 2025 | |
| Lihong Wang | Apr 8, 2025 | |
| Lihong Wang | Apr 9, 2025 | |
| Alfonso Nieto-Castanon | Apr 12, 2025 | |
| Lihong Wang | Apr 13, 2025 | |
| Alfonso Nieto-Castanon | Apr 8, 2025 | |
| Lihong Wang | Mar 31, 2025 | |
| Emanuele Pravata' | Dec 11, 2013 | |
| Alfonso Nieto-Castanon | Dec 18, 2013 | |
| Emanuele Pravata' | Dec 20, 2013 | |
| Emanuele Pravata' | Nov 28, 2013 | |
| Alfonso Nieto-Castanon | Nov 29, 2013 | |
| Emanuele Pravata' | Dec 2, 2013 | |
| Alfonso Nieto-Castanon | Dec 4, 2013 | |
| Emanuele Pravata' | Dec 4, 2013 | |