Hi Katarzyna

Only the PCA scores (one value per timepoint, for each component) are typically saved. If you check in Setup.Options the option that reads 'Create ROI-extraction REX files' that will create a number of REX*.mat files when running the Setup step (one file per ROI, Subject, and functional run) that contain more details about the data extraction, including the PCA loadings (one value per voxel, for each component) for the corresponding ROIs. Alternatively, due to the orthogonality of the scores in PCA you could also manually compute the PCA loadings simply by computing the correlation between each of the resulting CSF timeseries and the BOLD signal at each voxel within CSF (e.g. running SBC analyses using the CSF timeseries as seeds).

Hope this helps

Alfonso

Originally posted by Katarzyna Kazimierczak:

Hi,

 

I would like to perform some analysis of the pca decomposition of the CSF signal in the denosing step and I was wonderin where in the CONN .mat files are saved loadings of the pca of that signal?

 

Best,

Katarzyna Kazimierczak