Given that the Pairwise LiNGAM method requires non-Gaussian information to be retained in the timeseries (Ramsey et al., 2014), preprocessing was repeated substituting in FSL’s non-linear high-pass filter. Only high-pass filtering was performed given evidence that low-pass filtering removes important non-Gaussian information (Ramsey et al., 2014). For each connection, a pairwise LiNGAM coefficient was first estimated for each participant. Significance of analyses was determined via permutation (5000 permutations). In order to ensure that outliers did not drive findings, analyses were repeated after winsorization of LiNGAM coefficients to 2.5SD, after which all findings remained significant.
