Effects of Early Infant Nutrition on Aperiodic Exponent From 2 to 12 Months Using <scp>EEG</scp> Analysis

Neural development begins in gestation and rapidly accelerates throughout early life. The environmental effect of infant diet is a subject of increasing study as it is the basic nutritive sources which support biological processes essential for healthy development. Previous research in our group has found small but significant effects of nutrition on early cognitive developmental tests between children primarily fed human milk (BF), soy-based formula (SF), and dairy-based formula (MF) for the first 12 months of life. This investigation uses this same data set: a study throughout infancy from 2 to 12 months of life. This study seeks to compare brain maturation using EEG aperiodic exponent between infants who received breast milk feeding and those who received a dairy-based or soy formula. High-density electroencephalographic (EEG) recordings were taken at 2, 3, 4, 5, 6, 9, and 12 months of age using a 5-min silent video baseline. Using Specparam (formerly fitting oscillations and one-over-F or "FOOOF"), aperiodic activity was computed through a power spectral density (PSD) analysis for each session, which were then averaged per dietary group over left, right, and medial frontal and parietal regions of interest (ROIs) and one occipital ROI. Aperiodic exponent is a potential marker of neuromaturation, as it is hypothesized to relate to excitatory/inhibitory (E/I) balance and structural development in GABAergic systems. We used generalized estimating equations in order to evaluate differences in aperiodic exponent across dietary grouping as well as across age. Consistent with some previous findings, aperiodic exponent was found to decrease with age; however, no significant associations were found with infant diet except at 3 months of age in which BF infants had a larger aperiodic exponent than formula fed (FF) infants.