Caregiver Stress and Its Implications on Infant Functional Connectivity: A Novel EEG Coherence Study

Abstract

Electroencephalography (EEG) has long been used in the fields of developmental psychology and cognitive neuroscience to study changes in the brain across ages (Bell & Cuevas, 2012). The measures of EEG power and coherence have been shown to meaningfully predict future performance in language (Mundy, Card & Fox, 2003), cognitive processing (Bell, 2001) and working memory (Bell & Wolfe, 2007) suggesting their relevance in infant research. Adverse environmental experiences have been shown to cause significant deviations from normative trajectories in these electrophysiological signals (Marshall, Fox & BEIP Core Group, 2004) and these deviations have been attributed to a maturational lag suggesting a delay in CNS development (Corning, Steffy, Anderson & Bowers, 1986). Early life stress has been one of the proposed mechanisms of these functional changes, with research pointing out significant correlations with caregiver perceived stress (Pierce et al., 2019) and caregiver cumulative cortisol (Troller-Renfree et al., 2020) to infant EEG power. The current exploratory study sought to be the first to find significant associations between caregiver cortisol levels and infant EEG coherence, a measure of functional connectivity. Instead, bivariate linear modeling found that caregiver perceived stress was significantly negatively associated with right proximal coherence in the fronto-temporal and central regions (ps < 0.05). Multivariate modeling shows a more complicated picture, suggesting that future research must be done to create complex models of the effects of the environment on infant brain development. This study, however, is the first to provide evidence for the possible modulations caused by caregiver stress to infant functional connectivity at 3 months old, and reveals that more foundational work must be done on the changes in EEG coherence in the first year of life.