Figure 8.
A, The largest BOLD-CAs events (CA, above the 98th percentile of the RSS; Fig. 4C, green line) are distinguished from non-events (nCA, below threshold). We report the synthetic and empiric correlations between iFCs at times within CA events (left in every panel), between CA events and non-events nCA (center of panels), within non-events nCA (right of panels). These correlations are by definition the off-diagonal values of the dFCe matrix (see Fig. 2A,B). The distribution of the correlations within events is wider and explains the greatest off-diagonal correlation values of the dFCe across all the synthetic and empiric datasets. This principle is explicitly shown in panel B, where the original dFCe extracted from an empiric human trial (top) was sorted according to increasing RSS (bottom), leading to the clustering of high correlations toward high CA times. This shows that most of the non-trivial temporal correlations involve CA times falling in the last quartile of the RSS (above the 75th percentile, central green line). Thus, the strongest CA events drive the dynamics of FC.