8th Annual Lecture
George Eastman Professor, Brain & Cognitive Sciences and Linguistics
Chair, Brain & Cognitive Sciences
University of Rochester
March 17, 2006
Logan Hall Auditorium
How children shape languages: Language acquisition and the emergence of signed and spoken languages
As human children and adults learn their native languages, two apparently distinct phenomena occur. First, children (and, to some degree, adults) are remarkably adept at learning the details of the particular language to which they are exposed. Children exposed to English learn English, while those exposed to Japanese learn Japanese. To account for how they do this, Richard Aslin and I have been developing an approach to language acquisition known as “statistical learning.” Our basic idea is that human language acquisition involves naturally and unconsciously computing, over a stream of speech, such things as how frequently sounds co-occur, how frequently words occur in similar contexts, and the like. Learners use these computations to determine regular versus accidental properties of the language and to learn its rules. Our studies show that adults, infants, and even nonhuman primates perform such computations online and with remarkable speed, on both speech and nonspeech materials.
At the same time, children do not always acquire what they are exposed to: under certain circumstances, they reliably change languages. Studies of the emergence of Nicaraguan Sign Language, as well as other signed and spoken languages, suggests that children are a prime force in developing and expanding languages. Our research shows that this phenomenon can also be incorporated into an understanding of statistical learning. Even in the lab, given certain types of input, learners reliably change the patterns of the language; and children do this strikingly more often than adults.