|Pivik, Rudolph -|
|Andres, Aline -|
Submitted to: Brain and Language
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 3, 2011
Publication Date: January 3, 2012
Citation: Pivik, R.T., Andres, A., Badger, T.M. 2012. Effects of diet on early stage cortical perception and discrimination of syllables differing in voice-onset time: A longitudinal ERP study in 3 and 6 month old infants. Brain and Language. 120(1):27-41. Interpretive Summary: There are few studies comparing brain function in healthy infants fed the three major infant diets (breast milk, milk-based and soy formula) even though these diets differ significantly in nutrients. We looked at whether these diets influenced initial cortical responses to two different syllables when babies were 3 and 6 months old. All groups showed syllable-specific responses at both ages that were generally similar. However, initial responses were faster in breastfed than formula-fed infants and discrimination was greater in infants fed soy formula compared with other groups. The results show that the encoding and discrimination of speech sounds occurring in early stages of cortical processing are differentially influenced by infant diet.
Technical Abstract: The influence of infant diet on early stage cortical processing of syllables was examined in 239 healthy infants who were breastfed (BF) or fed milk-based formula (MF) or soy formula (SF). Using an oddball paradigm, event-related potentials to consonant-vowel syllables differing in voice-onset time were recorded over frontal and temporal brain areas specialized for language processing from infants at ages 3 and 6 months. Amplitude and latency measures of the P1 component across brain regions indicated that at both ages infants in all groups could extract and discriminate categorical information from syllables. Between-syllable amplitude differences indexing discrimination were present across groups, but were generally greater for SF infants. Significant differences in the timing of recruitment of language-related areas reflected earlier peak responses over speech-perception areas than speech-production areas in the left hemisphere. Encoding was faster in BF than formula-fed infants, but significantly faster only than SF infants. The results show that in preverbal infants: (1) encoding and discrimination of phonetic information are accomplished in early stages of cortical processing; (2) activation of brain regions of speech perception and production are sequenced in a manner that may be meaningfully related to language acquisition and speech functions; (3) these processes are differentially modulated by infant diet; and, (4) differences between formula groups do not indicate important influences of soy formula on brain function processes during the first postnatal 6 months.