Word-form recognition in 6-month-olds? Using event-related potentials to study the influence of infant-directed speech

Abstract: By 4.5 months infants listen longer to their names compared to matched foils, which is the earliest empirically demonstrated sign of word-form recognition. This ability develops gradually in the first year of life and becomes increasingly advanced. The present study investigated word-form recognition in 6-month-olds using event-related potentials (ERPs). To date, few studies have demonstrated word-form recognition at this age, and only one study has presented electrophysiological evidence. In addition, the present study investigated the effect of speech register on word-form recognition. Studies on language acquisition indicate that adjustments adults and older children make in interaction with infants are relevant for language learning. This speech register, commonly referred to as infant-directed speech (IDS), differs from adult-directed speech (ADS) in several respects. Studies on word-form recognition did typically not compare recognition effects for word forms familiarized (meaning trained) in IDS with word forms familiarized in ADS, however, the present study did. No recognition effects for either IDS or ADS were found. Moreover, there were no differences in ERP-responses for word forms familiarized in IDS compared to word forms familiarized in ADS. The main conclusion is that word-form recognition is still unstable at 6 months.