Orthogonalization of seeds' time-series

AFNI Message Board
1

Hello all,

I’ve been using 3dTcorr1D to calculate a seed’s whole brain correlation. Now, I would like to remove the mutual correlations’ variance between this seed and another seed correlation (maybe orthogonaling their time-series) and I thought maybe you had any suggestions about how to do this with afni or what function I could use. Sorry for the general question.

Thanks for any suggestions!
ana

2

Well, I’m not sure what your goal is, but you can orthogonalize a set of vectors using the 1dsvd program with the -1Dleft option. However, I’m not sure that will move you in the direction you want, but I can’t really tell what your goal is.

3

Thanks.
My goal is to calculate the functional connectivity of several seeds that are close to each other. Since they are close to each other, there will be a lot of common variance between them and I wanted to just see the unique variance for each of them. I thought I could do that (getting just the unique correlations for each seed) by orthogonalizing each seed’s time series with respect to the other seeds’ time series. I’ve been looking at a way of doing that with 3dDeconvolve, but I’m not sure that it’s possible. I was also checking today the 1dsvd program that you suggested, but I don’t think this will help me either.
Maybe I’m wrong and there’s an easier way of seeing the unique connectivity of each of these seeds.