complex_fmri

This repo contains R and C code accompanying the Annals of Applied Statistics paper "Complex-valued time series modeling for improved activation detection in fMRI studies".

The R functions are intended to be the user interface so I have written comments about them. The C functions are called by these R functions and represent the "inner workings" of the code so I have not commented these (though I am happy to include more upon request).

Here are summaries of what the functions do in each of the R files:

• processing-R_fcns.R Performs the detrending of the magnitude/phase time series components via the complex-valued running line as described in Section 3.1; performs spatial smoothing of the fMRI images as described in Section 3.2.
• order_det_fcns.R Detects the autoregressive (AR) order of the complex-valued time series as described in Section 3.5.
• complex_fcns.R For a complex-valued voxel time series, estimates the parameters and calculates the likelihood ratio test (LRT) statistic for activation.

I have only included the code related to the models for complex-valued fMRI time series here. I have excluded the code related to the models for the magnitude-only time series, though I can include this upon request.