Effects of Practice on Learning and Retention of Tool-Related Motor Skills in Parkinson's Disease

Previous research revealed that individuals with Parkinson’s disease (PD) show preserved learning of tool-related motor skills within a session. However, as a possible result of striatal dysfunction, retention has been found to be impaired after a 3-week delay. The goal of the current study was to further examine motor skill impairments related to complex tool use in PD by investigating the effects that different delays and extensive practice have on performance. PD participants and controls were trained on novel tools over four sessions, and motor skill performance was investigated by examining patterns of learning and forgetting over time. Results showed that PD participants were unimpaired in motor skill learning within sessions, but they did not retain these skills between sessions. In spite of forgetting, with practice, individuals with PD still demonstrated improvement across sessions. These findings indicate that people with PD may benefit from extensive practice when learning tool-related motor skills.