Investigating the cause of language regularization in adults: memory constraints or learning effects?

When language learners are exposed to inconsistent probabilistic grammatical patterns, they sometimes impose consistency on the language instead of learning the variation veridically. The authors hypothesized that this regularization results from problems with word retrieval rather than from learning per se. One prediction of this, that easing the demands of lexical retrieval leads to less regularization, was tested. Adult learners were exposed to a language containing inconsistent probabilistic patterns and were tested with either a standard production task or one of two tasks that reduced the demands of lexical retrieval. As predicted, participants tested with the modified tasks more closely matched the probability of the inconsistent items than did those tested with the standard task.