Speech motor learning in Parkinson disease

The purpose of this study was to determine whether persons with Parkinson disease (PD) have deficits in speech motor learning. The accuracy and temporal articulatory patterns of PD patients were compared to those of neurologically healthy adults (HS) to assess whether changes occurred as a function of practice in learning a novel speech utterance. HS demonstrated motor learning: They increased accuracy with reduced movement durations and variability while the participants with PD demonstrated increased accuracy at the expense of duration and variability. Neither group accurately retained the novel utterance following a distracter task. Relationships among accuracy, duration, and variability also supported these findings. Therefore, the basal ganglia appear to play a role in the skilled acquisition of novel speech motor patterns.