An Investigation into the Role of Implicit Knowledge in Adult Second Language Acquisition
Leonard Cook, Anna
This thesis investigates the role of implicit knowledge in second language acquisition, presenting five experiments and related simulations based on artificial grammar learning. It examines whether second language learners can acquire implicit knowledge of noun–verb agreement. In addition it tests whether their ability to do so is influenced by the number of words that intervene between the relevant noun and the finite verb in the input sentences, as this affects performance in artificial grammar learning, the serial response time task and the statistical learning paradigm. Experimental participants were exposed to a modified version of Persian or Basque while performing a memory task. Next, two grammaticality judgement tests (one timed and one untimed) and a sentence correction task assessed whether the participants had acquired either the target noun–verb agreement or pairs of adjacent words that appeared frequently in the learning items. Performance reflecting implicit and explicit knowledge was distinguished according to three criteria based on R. Ellis (2005) and according to the assumption that the former is not under conscious control. Participants’ performance suggested that they had implicit knowledge of the adjacent word pairs. Similarly, the results indicated that they had implicit knowledge of subject–verb agreement when a single word intervened between the subject and the verb, but not with two intervening words. Connectionist simulations supported the results and indicated that performance was unlikely to improve if more exposure were given. Although the influence of additional factors is discussed, the results generally supported the view that an increase in the number of intervening words reduces learning outcome. The intriguing similarity between the results of this thesis iv and previous research in artificial grammar learning, the serial response time task and statistical learning experiments suggests that future research should directly compare the paradigms to ascertain whether similar learning processes are engaged in each case.