When language learners are exposed to inconsistent probabilistic grammatical patterns they sometimes impose consistency on the language instead of learning the variation veridically. We hypothesize that this regularization results from problems with word retrieval, not learning per se. We test one prediction of this -that easing the demands of lexical retrieval leads to less regularization. We exposed adult learners to a language containing inconsistent probabilistic patterns and tested them using either a standard production task or one of two tasks that reduced the demands of lexical retrieval. As predicted, participants tested using the modified tasks more closely matched the probability of the inconsistent items than those tested using the standard task.
KeywordsLanguage acquisition; probability learning; retrieval; language production Typically children learn a language that looks very much like the input they received. This is not always the case, however; under certain circumstances the learner ends up speaking a language differently than those who provided the input. Although the most well-known cases involve the creation of grammatical patterns in an emerging language (e.g. Senghas, 2000;Senghas & Coppola, 2001;Senghas, Coppola, Newport, & Supalla, 1997), sometimes the changes involve the imposition of consistency and regularity on previously existing inconsistent patterns (Sankoff & Laberge, 1973;Singleton & Newport, 2004), something known as regularization.One explanation for this is that children, and only children, regularize languages because they innately know that human languages do not contain this kind of unpredictable variation (Becker & Veenstra, 2003;DeGraff, 1999;Lumsden, 1999). This explanation is rooted in a theoretical position that proposes that language is based primarily on domain specific knowledge and mechanisms. While this explanation for regularization is consistent with studies showing that children have a strong tendency to impose regularity on languages in contrast to adults who can learn probabilistic patterns, it cannot account for the finding that adults too will impose consistency under certain circumstances (Hudson Kam & Newport, 2005, in press).However, there is a growing body of work suggesting that at least some aspects of acquisition can be explained without positing innate knowledge specific to language (see Newport & Aslin, 2000), and we here explore the possibility that this might also be the case for regularization. That is, that regularization might emerge from more general aspects of cognition. Specifically, we propose that regularization results from memory constraints, or rather, aspects of language production that are sensitive to memory constraints -namely word retrieval. When retrieval is difficult, the most easily accessible form is over-retrieved, resulting in regularization. Our proposal then attempts to explain regularization as resulting from general cognitive constraints rather than anything specific to language or language learning.
