Implicit motor-sequence learning in humans following unilateral stroke: the impact of practice and explicit knowledge

Learning and memory are sub-served by two interrelated systems - explicit and implicit. Explicit memory involves facts, while one form of implicit memory involves perceptual-motor processes. The purpose of this series of experiments was to investigate the ability of individuals with stroke-related brain damage to demonstrate implicit motor-sequence learning and the relative impacts of (1) extended practice, or (2) explicit knowledge prior to practice. Implicit learning was severely impaired without explicit knowledge and even under conditions of extended practice. However, when explicit knowledge was provided prior to practice, participants with stroke demonstrated implicit motor-sequence learning. These data suggest that following unilateral stroke, providing explicit information about the task and sequence can attenuate implicit motor learning deficits. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.