Fukumoto Yuki, Bizen Hiroki, Todo Marina, Kimura Daisuke, Suzuki Toshiaki
Kansai University of Health Sciences, Faculty of Health Sciences, Department of Physical Therapy, 2-11-1 Wakaba Sennangun Kumatori, Osaka 590-0482, Japan; Graduate School of Kansai University of Health Sciences, Graduate School of Health Sciences, 2-11-1 Wakaba Sennangun Kumatori, Osaka 590-0482, Japan.
Kansai University of Health Sciences, Faculty of Health Sciences, Department of Occupational Therapy, 2-11-1 Wakaba Sennangun Kumatori, Osaka 590-0482, Japan.
Neuroscience. 2025 Mar 5;568:408-418. doi: 10.1016/j.neuroscience.2025.01.050. Epub 2025 Jan 27.
Elderly adults may have poorer recall ability than young adults and may not fully enjoy the effects of motor imagery. To understand the age bias of the effect of motor imagery on hand dexterity, we evaluated brain activation and spinal motor nerve excitability. Brain activation was evaluated from changes in oxygenated hemoglobin concentration, while spinal motor nerve excitability was evaluated from F-waves in eight young (mean age 21.0 ± 0.5 years) and eight elderly (mean age 69.5 ± 2.3 years) subjects of matched sex ratio at rest and during motor imagery. Purdue Pegboard scores were also measured before and after motor imagery, and changes in hand dexterity were assessed. The results showed that motor imagery improved hand dexterity without an age bias, and in a similar trend, spinal motor nerve excitability increased during motor imagery. Functional brain connectivity analysis showed the formation of a working memory network in both groups. However, in the analysis of single brain region activation, the young group, but not the elderly group, showed increased activity in the supplementary motor cortex during motor imagery. In addition, regardless of age-related changes, causal coupling indicated the supplementary motor cortex was associated with the changes of spinal motor nerve excitability. Although the changes in brain activation during motor imagery were influenced by age, motor imagery-induced improvements in hand dexterity are also expected in the elderly. Furthermore, changes in spinal motor nerve excitability may be useful in determining the qualitative aspects of motor imagery.
老年人的记忆能力可能比年轻人差，并且可能无法充分享受运动想象的效果。为了了解运动想象对手部灵活性影响的年龄偏差，我们评估了大脑激活和脊髓运动神经兴奋性。通过含氧血红蛋白浓度的变化来评估大脑激活，而通过静息和运动想象期间八名性别比例匹配的年轻受试者（平均年龄21.0±0.5岁）和八名老年受试者（平均年龄69.5±2.3岁）的F波来评估脊髓运动神经兴奋性。在运动想象前后还测量了普渡钉板分数，并评估了手部灵活性的变化。结果表明，运动想象可改善手部灵活性，且不存在年龄偏差，并且在运动想象期间脊髓运动神经兴奋性以类似趋势增加。功能性脑连接分析显示两组均形成了工作记忆网络。然而，在单脑区激活分析中，年轻组而非老年组在运动想象期间辅助运动皮层的活动增加。此外，无论与年龄相关的变化如何，因果耦合表明辅助运动皮层与脊髓运动神经兴奋性的变化有关。尽管运动想象期间大脑激活的变化受年龄影响，但预计老年人运动想象也会改善手部灵活性。此外，脊髓运动神经兴奋性的变化可能有助于确定运动想象的定性方面。
