Figure 4.

Reduction in age-associated differences in motor output variability with short-term practice. The figure shows the short-term adaptations in end-point variability for young (white bars) and older (black bars) adults during a single session of practicing a goal-directed isometric force task (data adapted from (11)). It is clear that after four blocks of practice (~40 trials), older adults exhibited similar end-point variability in force with young adults, which they maintained throughout the session. These fast adaptations suggest that older adults adjust neural mechanisms (sensory or motor adaptations) to reduce motor output variability.