PhD Scientific Days 2024

Mental Health Sciences I.

Beyond Adolescence: Longitudinal Patterns of Hierarchical Brain Organization

Text of the abstract

Introduction: The relationship between adolescent brain reorganization and the timing of puberty is not yet understood, further complicated by the high individual variability in pubertal timing and the difficulty to distinguish between chronological age (CA) and pubertal maturity. Aims: We investigated the impact of pubertal timing on the hierarchical organization of the default mode network, using ultrasonic bone age (BA) measurements as a reliable indicator of pubertal maturity, combined with entropy production calculations, an index of hierarchical brain organization. Methods: We applied entropy production calculations on 87 eyes-closed resting-state EEG recordings (alpha frequency range), collected from 61 adolescent females categorized into three developmental stages (decelerated, average, accelerated) across two chronological age groups, and 26 emerging adult females. Recordings were divided into 12 phase-based connectivity patterns to analyze the sequence and asymmetry of their transitions. To separate the effects of CA and BA, data were analyzed through various grouping approaches including age groups, maturity groups, and maturity groups within age groups. We are in the process of forming a longitudinal dataset by collecting new EEG data from the original adolescent cohort. Results: Entropy production was significantly higher in the average maturity group compared to both the decelerated and accelerated groups among adolescents. Analysis of the longitudinal data is ongoing. Conclusion: The recently published results suggest an advantage of on-time maturation in terms of hierarchical brain organization in adolescence within the default mode network, its activity captured by our resting-state EEG measurements. We are now performing analyses on the longitudinal dataset to verify if this pattern is transient or persists long-term. The study is clinically relevant as extreme deviations in maturation speed might permanently increase neurodiversity, leading developmental trajectories into the clinical spectrum. Funding: The project was supported by the National Research, Development and Innovation Office of Hungary (Grant K-134370 to I.K.), by the Hungarian Research Network (HUN-REN-ELTE-PPKE Adolescent Development Research Group), and the PPKE-BTK-KUT-23-1 project funding by the Faculty of Humanities and Social Sciences, Pázmány Péter Catholic University.