For temporal characteristics analysis, the timecourse associated with each DMN component was transformed into the frequency domain using Fourier transformations. We averaged the resultant power spectra for each subject group, and average data points into bins of 0.02 Hz. We then carried out a repeated-measures analysis of variance (ANOVA) on the resulting histograms to explore differences in the power distribution between groups. To explore the impact of PANSS and YMRS scores, we created high and low score groups using a median split, and compared power distribution in these groups (N=8 and 6 for low- and high-PANSS subgroups within schizophrenia, respectively; N=9 and 8 for low- and high-YMRS subgroups within bipolar disorder, respectively). We also calculated a midpoint of power distribution (shifts in power spectrum towards higher frequencies lead to rightward shifts of midpoint) and correlated this midpoint with YMRS and PANSS scores.
