Diet and gender are important factors modulating low frequency EEG activity during processing of language sounds in 3 month old infants

Little is known about how early postnatal diet affects brain processes related to cognitive function in healthy infants. To address this question we examined EEG activity recorded from 3 month old infants [breastfed (BF: n = 104, 55 males), milk‐based formula fed (MF: n = 114, 57 males) or soy formula fed (SF: n = 108, 55 males)] as they were being presented two syllables (oddball paradigm). Time‐frequency analyses were conducted on EEG (.5–12 Hz in 2 Hz bands) recorded over temporal brain regions during the first 250 msec following syllable presentation. Data were analyzed using ANOVAs and post‐hoc t‐tests. Group differences in post‐stimulus power [BF > MF (across bands, all p ≤ .05); BF > SF (10–12 Hz, p < .05) largely reflected gender influences, i.e., Males: BF > MF, all bands, p ≤ .05; SF > MF, .5–6 Hz, p ≤ .05); BF > SF,10–12 Hz, p ≤ .05; Females: all across‐group and frequency comparisons of response power were non‐significant. Only MF infants showed gender differences in power (females > males: 4 Hz and above, all p ≤ .05). These findings show that: early infant diets differentially influence the development of EEG neural networks engaged during initial acoustic and phonemic evaluation of language sounds; these networks are least‐well developed in MF males; among males in formula groups, network development was greater in SF than MF infants; and, no diet effects were observed in females. (USDA CRIS 6251‐51000‐002‐00D)