Talking Brains: Neonatal Aperiodic Activity in Resting State EEG Relates to Later Communicative Abilities

Communicative abilities acquired over the first year of life are foundational for language development. Understanding the neural mechanisms underlying these abilities can explain individual differences and improve predictions of later language outcomes. While prior research on neural markers of language development has focused predominantly on oscillatory neural activity, the underlying aperiodic component of the neural signal may provide further insights into cortical maturation by indirectly reflecting variation in neural excitation/inhibition (E/I) balance. In neurodevelopmental conditions, both reduced and elevated aperiodic activity are linked to atypical development, and initial evidence from at-risk cohorts also relates aperiodic activity to language outcome. Moving beyond clinical populations, the present study examined whether aperiodic activity during neonatal resting-state EEG relates to 12-month communicative abilities in typically developing infants. Aperiodic offset and exponent were extracted from resting-state EEG recorded two weeks after birth in n = 50 neonates using the FOOOF algorithm. At 12 months, communicative abilities were assessed with the parent-report CSBS-DP Infant-Toddler Checklist. Quadratic regression analyses showed an inverted U-shaped relationship between the neonatal aperiodic exponent and communicative abilities: both lower and higher exponent values were associated with poorer outcomes, with intermediate values linked to better abilities. No robust association was found for the offset. These findings suggest that aperiodic activity captures variability in early communicative development, with an optimum at intermediate levels, consistent with a balanced E/I state. The scope of aperiodic brain activity as a developmental marker may thus extend beyond clinical populations to predicting communicative development in healthy infants.