Ability to segment words from speech as a precursor of later language development : insights from electrophysiological responses in the infant brain

Infants' ability to recognize words in continuous speech is vital for building a vocabulary. Event-Related Potentials (ERPs) reveal a clear recognition response for familiarized words, relative to unfamiliar words, in 10-month-olds, but not consistently in seven-month-olds. We report three studies relating this ERP segmentation measure to later language development. First, seven-month-olds with ERPs similar to the 10-month-old norm displayed significantly higher language scores at three years of age than seven-month-olds with different ERPs. Second, 10-month-olds who recognized words previously presented once, within an utterance, later had larger vocabularies than 10-month-olds who could not perform this task. Third, infants who recognized words heard in continuous speech when they reoccurred in continuous speech outperformed infants who did not show this pattern on known-word recognition at 16 months. Hence, with a variety of measures, we see that the ERP segmentation effect serves as a robust predictor of the degree of later language development