Because our findings could be particularly sensitive to potential movement confounds, additional corrections for movement were applied. Movement generally results in changes in MRI signal. Thus, we also evaluated MRI signal change by comparing each BOLD volume and the preceding volume to exclude volumes with excessive movement (Shannon et al., 2011). An algorithm was used to measure the variance in BOLD signal and exclude the volumes (or frames) whose variation was more than 3 standard deviations above the mean (for details see Shannon et al. (2011)).
