The influence of normal human ageing on automatic movements

Area of Science:

• Neuroscience
• Motor Control
• Aging Research

Background:

• Older adults often exhibit difficulties in motor automaticity compared to younger individuals.
• The specific central neural mechanisms underlying age-related differences in automaticity remain largely unknown.

Purpose of the Study:

• To investigate the impact of normal aging on motor automaticity using functional magnetic resonance imaging (fMRI).
• To explore the neural correlates associated with achieving automaticity in sequential motor tasks across different age groups.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was employed to monitor brain activity.
• Healthy aged and young subjects practiced self-paced, memorized sequential finger movements until automaticity was achieved.
• Automaticity was assessed by the ability to perform a secondary task concurrently with the primary motor task.

Main Results:

• Most aged subjects successfully achieved automaticity in complex motor tasks, comparable to young subjects, albeit with increased practice time.
• fMRI revealed similar brain regions activated for sequential movements in both groups, both before and after automaticity.
• Aged subjects demonstrated greater activation in specific brain regions, including the cerebellum, premotor cortex, parietal cortex, prefrontal cortex, anterior cingulate, caudate nucleus, and thalamus, when performing automatic movements compared to young subjects.

Conclusions:

• Healthy aging does not preclude the achievement of automaticity in complex motor tasks.
• Older adults require heightened neural activity in several brain regions to attain the same level of motor automaticity as younger adults.
• Increased brain activation in aged individuals is likely the primary factor contributing to their challenges in achieving motor automaticity.