Issues in Applied Linguistics

This paper presents a neurobiologically inspired model of one aspect of adult second language acquisition (SLA): procedural linguistic skill acquisition. Procedural linguistic skills are defined as the speaker/learner's implicit, unstatable knowledge regarding the formal linguistic (i.e., syntactic, phonological, and morphological) properties of the second language (L2). Unlike declarative linguistic knowledge (i.e., semantic and lexical knowledge and explicit knowledge of the L2 linguistic system), which can be readily displayed through verbal report or description, procedural linguistic skills are best demonstrated through performance. The proposed acquisition model crucially involves the neural circuitry of the neocerebellum. The neocerebellum is a brain structure which, although traditionally associated with purely motor activity, has recently been implicated in higher cognitive and, potentially, linguistic functions. The model provides for a potential unification of the competing cerebral (Ojemann, 1991 ; Loritz, 1991) and cerebellar (Rumelhart & McClelland, 1986: Sokolik, 1990) theories of linguistic function by integrating the unique contributions of both regions of the cerebral cortex (e.g., Broca's expressive speech area and the prefrontal cortex responsible for cognitive planning and monitoring functions) and regions of the cerebellum (an enormous capacity parallel processor responsible for the integration of cognitive and sensory information). The proposed model also offers a principled account of how explicit formalized grammar instruction might potentially serve as an effective metacognitive strategy for the L2 learner's acquisition of procedural linguistic skills.