Attention to Explicit and Implicit Contrast in Verb Learning.

Contrast information could be useful for verb learning, but few studies have examined children's ability to use this type of information. Contrast may be useful when children are told explicitly that different verbs apply, or when they hear two different verbs in a single context. Three studies examine children's attention to different types of contrast as they learn new verbs. Study 1 shows that 3 ½-year-olds can use both implicit contrast ("I'm meeking it. I'm koobing it.") and explicit contrast ("I'm meeking it. I'm not meeking it.") when learning a new verb, while a control group's responses did not differ from chance. Study 2 shows that even though children at this age who hear explicit contrast statements differ from a control group, they do not reliably extend a newly learned verb to events with new objects. In Study 3, children in three age groups were given both comparison and contrast information, not in blocks of trials as in past studies, but in a procedure that interleaved both cues. Results show that while 2 ½-year-olds were unable to use these cues when asked to compare and contrast, by 3 ½, children are beginning to be able to process these cues and use them to influence their verb extensions, and by 4 ½ years, children are proficient at integrating multiple cues when learning and extending new verbs. Together these studies examine children's use of contrast in verb learning, a potentially important source of information that has been rarely studied.