There is one script, SpinalCompCor.m, that is used to perform PCA and calculate nuisance regressors. The two other scripts, parallelAnalysis.m and IAAFT.m, are used to perform the parallel analysis to determine how many regressors to retain for modeling.
Kimberly J. Hemmerling, Andrew D. Vigotsky, Charlotte Glanville, Robert L. Barry, Molly G. Bright; Data-driven denoising in spinal cord fMRI with principal component analysis. Imaging Neuroscience 2026; 4 IMAG.a.1143. doi: https://doi.org/10.1162/IMAG.a.1143