Early infant diet and ERP correlates of speech stimuli discrimination in 9 month old infants

Abstract

Processing and discrimination of speech stimuli were examined during the initial period of weaning in infants enrolled in a longitudinal study of infant diet and development (the Beginnings Study). Event‐related potential measures (ERP; 128 sites) were used to compare the processing of speech stimuli in healthy 9‐month old, full‐term infants who were exclusively breast‐fed (BF, n = 60) with those fed milk‐ (MF, n = 59) or soy‐based formula (SF, n = 61) since 2 months of age. ERPs were recorded in awake infants to two syllables (/pa/ and /ba/; randomized 80%:20% occurrence) and analyzed using ANOVA procedures with post‐hoc t‐tests. Data are reported for responses during the first 600 ms post‐stimulus in central and anterior temporal cortical areas. Significant (p < .05) between‐syllable differences in amplitude (/ba/ > /pa/) and latency (/ba/ < /pa/) were observed in all groups and generally similar across groups. However, greater between‐syllable amplitude differences for the late N450 component in BF and MF relative to SF infants suggests more extensive language‐related processing in BF and MF groups at this time. Whether these response patterns reflect transient diet‐related variations in syllable processing or represent differences that influence later language development may be clarified as this longitudinal study progresses. (Supported by USDA CRIS 6251‐51000‐002‐03S)