The Influence of Early Life Stress on the Development of Neural Representations during Mentalizing

Early life stress (ELS) has been linked to altered social cognition, yet the underlying neurodevelopmental mechanisms have yet to be fully understood. A recent 20-year longitudinal study examined 89 young adults' performance on the Reading the Mind in the Eyes Test (RMET) alongside a control condition during functional magnetic resonance imaging (fMRI).

Researchers looked at two ELS indices separately: a prospective cumulative risk score derived from caregiver wellbeing during pregnancy and their child's first year, and a retrospective self-report of adverse experiences from the participants in late adolescence. The study utilized univariate activation, representational similarity analysis (RSA), and inter-subject RSA to characterize neural outcomes.

The prospective ELS index was linked to better RMET performance. During RSA and inter-subject RSA, which tested two ways of measuring intersubject similarity in ELS - absolute pairwise difference and pairwise average - a region in the left anterior inferior frontal sulcus stood out as being affected by one index. The pairwise average approach showed that participants with low ELS exposure exhibited neural representational geometry more akin to the control group, while those with high ELS exposure displayed increasingly unique neural representational patterns.

Intriguingly, higher prospective ELS was associated with weaker performance on the RMET compared to the control condition within this same region.

Interestingly, retrospective ELS did not show any behavioral or neural associations. This research sheds new light on the neural representations of mentalizing using the RMET and their susceptibility to early life stress. Furthermore, it highlights the potential need to differentiate mentalizing tasks from lexical-semantic and semantic-control demands in future research.