# Early psychosocial deprivation alters the refinement of neural dynamics across adolescence

## TL;DR

Early psychological deprivation disrupts the normal development of brain dynamics during adolescence, affecting cognitive control.

## Contribution

This study shows that early adversity alters the trajectory of neural dynamics linked to cognitive control during adolescence.

## Key findings

- Eigenvalue magnitude of neural dynamics decreases with age during adolescence.
- Children with institutional care histories have higher eigenvalues, indicating disrupted neural refinement.
- Higher eigenvalues correlate with poorer cognitive task performance in adolescents.

## Abstract

Adolescence is a period of major behavioral and neural change. Here, we use modeling to examine how the trajectory of recurrent computations supporting cognitive control develops across adolescence. Using data from the Bucharest Early Intervention Project, we assessed how early adversity affects this trajectory. We analyzed electroencephalography (EEG) activity during a Flanker task and modeled trial-by-trial dynamics as a linear dynamical system. We found that eigenvalue magnitude—reflecting the temporal persistence of neural dynamics—decreases with age and that early psychological deprivation alters this trajectory. These findings align with theoretical predictions linking excitatory synaptic pruning to changes in neural dynamics and highlight the lasting influence of early experience on adolescent network refinement.

Adolescence is a crucial period for the refinement of neural circuits and cognitive skills. During this time, executive functions mature alongside pronounced structural changes in the brain, including reductions in synapse density. Computational models suggest that synaptic pruning enhances performance by stabilizing neural dynamics—deepening attractor basins and accelerating return to baseline after perturbation. Here, we tested these predictions using EEG data from the Bucharest Early Intervention Project, a randomized controlled trial of foster care as an alternative to institutionalized care. Trial-by-trial EEG residuals during a Flanker task were modeled as a linear dynamical system, and changes in eigenvalue magnitude were tracked across adolescence. Across all groups, eigenvalues decreased with age, consistent with maturation of recurrent computations. However, children with histories of institutional care exhibited consistently higher eigenvalues, suggesting delayed or disrupted refinement of the neural dynamics. Importantly, higher eigenvalues were associated with poorer behavioral performance on the task, linking altered neural dynamics to altered executive functions. These findings demonstrate that early deprivation leaves a lasting imprint on the developmental trajectory of neural dynamics, affecting the maturation of brain systems underlying cognitive control.