Tests of a dual-system model of speech category learning

In the visual domain, more than two decades of work has argued for the existence of dual category learning systems. The REFLECTIVE system uses working memory in an explicit fashion to develop and test rules for classifying. The REFLEXIVE system operates by implicitly associating perception with actions that lead to reinforcement. Dual-system models posit that in learning natural categories, learners initially use the reflective system and with practice, transfer control to the reflexive system. The role of reflective and reflexive systems in second language (L2) speech learning has not been systematically examined. In the study reported in this paper, monolingual native speakers of American English were trained to categorize Mandarin tones produced by multiple speakers. Our computational modeling approach demonstrates that learners use reflective and reflexive strategies during tone category learning. Successful learners use speaker-dependent, reflective analysis early in training and reflexive strategies by the end of training. Our results demonstrate that dual-learning systems are operative in L2 speech learning. Critically, learner strategies directly relate to individual differences in successful category learning.