Early word learners' ability to access phonetic detail in well-known words.

Several recent studies from our laboratory have shown that 14-month-old infants have difficulty learning to associate two phonetically similar new words to two different objects when tested in the Switch task. Because the infants can discriminate the same phonetic detail that they fail to use in the associative word-learning situation, we have argued that this word-learning failure results from a processing overload. Here we explore how infants perform in the Switch task with already known minimally different words. The experiment involved the same phonetic difference as used in our earlier word-learning studies. Following habituation to two familiar minimal pair object-label combinations (ball and doll), infants of 14 months looked longer to a violation in the object-label pairing (e.g., label 'ball' paired with object doll) than to an appropriate pairing. These results using well known words are consistent with the pattern of data recently obtained by Swingley and Aslin (2002) in which it was found that infants of 14 months look longer to the correct object when the accompanying well known word is spoken correctly rather than mispronounced. We discuss how these results are compatible with the limited resource explanation originally offered by Stager and Werker (1997).