PREFERRED TEMPO INFLUENCE ON LEARNING TRANSFER FROM PERCEPTUAL TO STEPPING TIMING IN PARKINSON'S DISEASE

One of the most disabling motor manifestations of Parkinson’s disease (PD) is increased temporal inter-step variability, which substantially elevates the risk of falls. In addition, individuals with PD also exhibit increased temporal discrimination thresholds and systematically overestimate the duration of sub-second events. Together, this evidence suggests that PD impairs sensorimotor processing in the hundreds of milliseconds range. Previous work has shown that intensive temporal perceptual training in healthy subjects can reduce the temporal variability during self-paced tapping. Building on these findings, we implemented an intervention aimed at reducing inter-step variability in individuals with PD. Seventeen patients underwent daily training for one week to improve temporal discrimination threshold, using each patient’s preferred tempo as the base interval. Inter-step interval variability was assessed on the first and last training days during a self-paced marching-in-place task and a synchronization-continuation task. On average, patients showed a reduction in temporal discrimination thresholds, accompanied by a significant decrease in inter-step variability across both tasks. Further analysis revealed two distinct behavioral subgroups. Patients with longer preferred tempo (>650 ms) exhibited significant improvements in both temporal discrimination and inter-step variability, whereas patients with a shorter preferred tempo (<650 ms) showed no significant changes in either perceptual or motor measures. Our results suggest that the efficacy of intensive temporal perceptual training in PD critically depends on the individual’s preferred tempo, with patients exhibiting slower preferred tempos deriving the greatest benefit.