Trait-like stability of selfhood triumvirate and its constituent aspects: A qEEG intra-individual test-retest...

This study investigated the intraindividual stability and reliability of the three core aspects of the Selfhood triumvirate ('Self', 'Me', and 'I') as well as their mutual relationship (the Selfhood triumvirate configuration/pattern) by measuring the within-subjects reproducibility of functional integrity within three operational modules (OMs) of the brain's self-referential network (SRN), each associated with one of these aspects, upon repeat testing (test-retest reliability). Our findings revealed statistically robust, moderate-to-high intraindividual test-retest reliability for the individual aspects ('Self', 'Me', and 'I'), and exceptionally high reliability for their overall functional configuration (i.e., the relative proportion of expression among the three aspects). Importantly, the analyses did not provide evidence that the duration between assessments, participants' age, or the presence of somatic or psychopathological conditions moderated these reliability measures. Taken together, the results suggest that the 'Self', 'Me', and 'I' aspects of the Selfhood triumvirate, as well as their overall functional configuration, exhibit trait-like properties, albeit to varying degrees, measured as the stability of functional integrity within the corresponding SRN OMs across time, age, and normative versus pathological conditions. Limitations of the present study and directions for future research are discussed.