Alzheimer’s disease (AD) is characteristically associated with motor and cognitive disorders and significantly reduces patients’ functional capabilities for independent living and quality of life. This study documented the role of motor learning and practice on motor performance for AD patients and seniors with mild cognitive impairment (MCI). Furthermore, it was designed to determine whether the abilities to "preplan" motor responses is critical in producing fast, consistent, and smooth movements for AD and MCI patients.
Twenty-eight seniors with a diagnosis of probable AD (M = 72.6 ± 8.3 years), 29 seniors with MCI (M = 73.9 ± 8.7 years) and 31 age-, education-, and sex-matched seniors (M = 71.6 ± 7.7 years) either practiced or did not practice on a task of fast aiming arm movement on a digitizer tablet. The performances in the variables of movement speed, smoothness, and the percentage of programming control were examined among AD, MCI, and control groups across 6 blocks of experiment (baseline and 5 training sessions). In addition, the profiles of movement displacement, velocity, and acceleration were compared among the groups.
The analyses indicate that seniors with AD or MCI seemed to adopt an approach of "online" correction while performing the aiming arm movement. As a result, their movement executions were slower, less smooth, and temporally more inconsistent or less coordinated than their healthy counterparts. However, as a function of practice, most seniors demonstrated an increased level of motor planning for initiating and controlling movements. AD patients and seniors with MCI improved their motor performance on a smaller scale than the normal controls. The cognitive deficits of AD and MCI patients in attention, perception, memory, and motor planning might reduce motor performance and learning.
The results of this research may have sound theoretical and practical implications for understanding motor control and learning mechanisms of AD or MCI patients and facilitating the formation of suitable therapeutic programs for seniors with and without AD or MCI.