Neural Correlates of Motor Skill Learning Are Dependent on Both Age and Task Difficulty

Josje M Bootsma; Simone R Caljouw; Menno P Veldman; Natasha M Maurits; John C Rothwell; Tibor Hortobágyi

doi:10.3389/fnagi.2021.643132

Neural Correlates of Motor Skill Learning Are Dependent on Both Age and Task Difficulty

Front Aging Neurosci. 2021 Mar 22:13:643132. doi: 10.3389/fnagi.2021.643132. eCollection 2021.

Authors

Josje M Bootsma¹, Simone R Caljouw¹, Menno P Veldman^{2

3}, Natasha M Maurits⁴, John C Rothwell⁵, Tibor Hortobágyi¹

Affiliations

¹ Department of Human Movement Sciences, University Medical Center Groningen, University of Groningen, Groningen, Netherlands.
² Movement Control and Neuroplasticity Research Group, Department of Movement Science, KU Leuven, Leuven, Belgium.
³ Leuven Brain Institute, KU Leuven, Leuven, Belgium.
⁴ Department of Neurology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands.
⁵ Sobell Department of Motor Neuroscience and Movement Disorders, University College London (UCL) Institute of Neurology, London, United Kingdom.

Abstract

Although a general age-related decline in neural plasticity is evident, the effects of age on neural plasticity after motor practice are inconclusive. Inconsistencies in the literature may be related to between-study differences in task difficulty. Therefore, we aimed to determine the effects of age and task difficulty on motor learning and associated brain activity. We used task-related electroencephalography (EEG) power in the alpha (8-12 Hz) and beta (13-30 Hz) frequency bands to assess neural plasticity before, immediately after, and 24-h after practice of a mirror star tracing task at one of three difficulty levels in healthy younger (19-24 yr) and older (65-86 yr) adults. Results showed an age-related deterioration in motor performance that was more pronounced with increasing task difficulty and was accompanied by a more bilateral activity pattern for older vs. younger adults. Task difficulty affected motor skill retention and neural plasticity specifically in older adults. Older adults that practiced at the low or medium, but not the high, difficulty levels were able to maintain improvements in accuracy at retention and showed modulation of alpha TR-Power after practice. Together, these data indicate that both age and task difficulty affect motor learning, as well as the associated neural plasticity.

Keywords: aging; electroencephalography; motor learning; plasticity; spectral analysis; task difficulty.