Heuninckx Sofie, Wenderoth Nicole, Debaere Filiep, Peeters Ronald, Swinnen Stephan P
Department of Kinesiology, Katholieke Universiteit Leuven, B-3001 Heverlee, Belgium.
J Neurosci. 2005 Jul 20;25(29):6787-96. doi: 10.1523/JNEUROSCI.1263-05.2005.
Although functional imaging studies have frequently examined age-related changes in neural recruitment during cognitive tasks, much less is known about such changes during motor performance. In the present study, we used functional magnetic resonance imaging to investigate age-related changes in cyclical hand and/or foot movements across different degrees of complexity. Right-handed volunteers (11 young, 10 old) were scanned while performing isolated flexion-extension movements of the right wrist and foot as well as their coordination, according to the "easy" isodirectional and "difficult" nonisodirectional mode. Findings revealed activation of a typical motor network in both age groups, but several additional brain areas were involved in the elderly. Regardless of the performed motor task, the elderly exhibited additional activation in areas involved in sensory processing and integration, such as contralateral anterior insula, frontal operculum, superior temporal gyrus, supramarginal gyrus, secondary somatosensory area, and ipsilateral precuneus. Age-related activation differences during coordination of both segments were additionally observed in areas reflecting increased cognitive monitoring of motor performance, such as the pre-supplementary motor area, pre-dorsal premotor area, rostral cingulate, and prefrontal cortex. In the most complex coordination task, the elderly exhibited additional activation in anterior rostral cingulate and dorsolateral prefrontal cortex, known to be involved in suppression of prepotent response tendencies and inhibitory cognitive control. Overall, these findings are indicative of an age-related shift along the continuum from automatic to more controlled processing of movement. This increased cognitive monitoring of movement refers to enhanced attentional deployment, more pronounced processing of sensory information, and intersensory integration.
尽管功能成像研究经常考察认知任务期间与年龄相关的神经募集变化,但对于运动表现期间的此类变化却知之甚少。在本研究中,我们使用功能磁共振成像来探究不同复杂程度的周期性手部和/或足部运动中与年龄相关的变化。右利手志愿者(11名年轻人,10名老年人)在按照“简单”同向和“困难”非同向模式进行右手腕和足部的孤立屈伸运动及其协调运动时接受扫描。研究结果显示,两个年龄组均激活了典型的运动网络,但老年人还涉及其他几个脑区。无论执行何种运动任务,老年人在涉及感觉处理和整合的区域,如对侧前脑岛、额下回、颞上回、缘上回、次级躯体感觉区和同侧楔前叶,均表现出额外激活。在反映对运动表现认知监测增加的区域,如前补充运动区、背侧前运动区、喙状扣带回和前额叶皮质,还观察到两个节段协调期间与年龄相关的激活差异。在最复杂的协调任务中,老年人在前喙状扣带回和背外侧前额叶皮质表现出额外激活,已知这些区域参与抑制优势反应倾向和抑制性认知控制。总体而言,这些发现表明在从自动运动处理到更受控制的运动处理的连续过程中存在与年龄相关的转变。这种对运动的认知监测增加涉及注意力分配增强、感觉信息处理更明显以及跨感觉整合。