Effects of early infant nutrition on aperiodic exponent from 2 to 12 months using EEG analysis

Authors: GILBREATH, DYLAN - University Of Maryland; ANDREWS, ADAM - Hendrix College; HAYGOOD, DARCY - Arkansas Children'S Nutrition Research Center (ACNC); ANDRES, ALINE - University Arkansas For Medical Sciences (UAMS); LARSON-PRIOR, LINDA - University Arkansas For Medical Sciences (UAMS)

Submitted to: Psychophysiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/14/2026
Publication Date: 2/5/2026
Citation: Gilbreath, D., Andrews, A., Haygood, D., Andres, A., Larson-Prior, L. 2026. Effects of early infant nutrition on aperiodic exponent from 2 to 12 months using EEG analysis . Psychophysiology. 63(2):Article e70247. https://doi.org/10.1111/psyp.70247.
DOI: https://doi.org/10.1111/psyp.70247

Interpretive Summary: Infant diet is the source of the energy needed to drive the rapid development of the brain in the first year of life, Our lab has previously reported small but significant effects of the choice to feed human breast milk, cow milk based formula or soy based formula in infants between the ages of 2 and 4 months even as these children reach the age of 6 years. In this study we examined brain activity in this same population between the ages of 2 to 12 months, asking whether there were differences based on chosen diet in aperiodic activity in the brain, which is believed to reflect brain maturation and the balance of excitation and inhibition in the brain and which has been reported by others to change with increasing age. We analyzed these data for longitudinal changes in aperiodic brain activity, asking whether diet and age significantly impacted that signal. Here we report that, as others have seen but in a larger number of infants, there was a clear and significant decrease in the aperiodic signal with age. While at 3 months of age the aperiodic signal was higher in human breast milk fed infants than in formula fed infants, overall diet was not found to significantly impact the aperiodic signal.

Technical Abstract: 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 dataset: 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 five-minute 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.