Once all frequency pairs had been tested, the comodulogram significance matrix was inspected for regions where the tests were significant across many neighboring frequency pairs, or clusters. Rectangular boundaries for each candidate cluster were determined by positioning a window of analysis, i.e., a cluster-specific PA domain, to tightly encompass the cluster of significant p-values in the S-matrix and the maximum PAC differences in the cluster as it appears in the D-matrix. Inclusion criteria for the initial set of candidate clusters were imposed for both matrices. The adjacent significant p-values comprising the cluster in the S-matrix had to span at least 1 Hz along the axis of either the amplitude or phase frequency, and their accompanying cluster of PAC differences at it appeared in the D-matrix had to span at least 1 Hz × 1 Hz in size. Multiple small but closely neighboring clusters were grouped together if they all fell within a PA domain with dimensions at least 1 Hz × 1 Hz. Only clusters considered for analysis were those falling within one of the standard PA domains represented on
