Pollok Bettina, Hagedorn Amelie, Krause Vanessa, Kotz Sonja A
Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, University Hospital Düsseldorf, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.
Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands.
Front Aging Neurosci. 2023 Jan 10;14:1048610. doi: 10.3389/fnagi.2022.1048610. eCollection 2022.
Precise motor timing including the ability to adjust movements after changes in the environment is fundamental to many daily activities. Sensorimotor timing in the sub-and supra-second range might rely on at least partially distinct brain networks, with the latter including the basal ganglia (BG) and the prefrontal cortex (PFC). Since both structures are particularly vulnerable to age-related decline, the present study investigated whether age might distinctively affect sensorimotor timing and error correction in the supra-second range.
A total of 50 healthy right-handed volunteers with 22 older (age range: 50-60 years) and 28 younger (age range: 20-36 years) participants synchronized the tap-onsets of their right index finger with an isochronous auditory pacing signal. Stimulus onset asynchronies were either 900 or 1,600 ms. Positive or negative step-changes that were perceivable or non-perceivable were occasionally interspersed to the fixed intervals to induce error correction. A simple reaction time task served as control condition.
In line with our hypothesis, synchronization variability in trials with supra-second intervals was larger in the older group. While reaction times were not affected by age, the mean negative asynchrony was significantly smaller in the elderly in trials with positive step-changes, suggesting more pronounced tolerance of positive deviations at older age. The analysis of error correction by means of the phase correction response (PCR) suggests reduced error correction in the older group. This effect emerged in trials with supra-second intervals and large positive step-changes, only. Overall, these results support the hypothesis that sensorimotor synchronization in the sub-second range is maintained but synchronization accuracy and error correction in the supra-second range is reduced in the elderly as early as in the fifth decade of life suggesting that these measures are suitable for the early detection of age-related changes of the motor system.
精确的运动计时，包括在环境变化后调整动作的能力，是许多日常活动的基础。亚秒级和超秒级范围内的感觉运动计时可能至少部分依赖于不同的脑网络，后者包括基底神经节（BG）和前额叶皮层（PFC）。由于这两个结构特别容易受到与年龄相关的衰退影响，本研究调查了年龄是否可能对超秒级范围内的感觉运动计时和错误校正产生独特影响。
共有50名健康的右利手志愿者，其中22名年龄较大（年龄范围：50 - 60岁），28名年龄较小（年龄范围：20 - 36岁），他们将右手食指的敲击起始与等时听觉起搏信号同步。刺激起始异步时间为900或1600毫秒。偶尔会在固定间隔中穿插可感知或不可感知的正向或负向阶跃变化，以诱导错误校正。一个简单反应时任务作为对照条件。
与我们的假设一致，超秒级间隔试验中的同步变异性在老年组中更大。虽然反应时不受年龄影响，但在正向阶跃变化的试验中，老年人的平均负异步性显著更小，这表明老年人对正向偏差的耐受性更强。通过相位校正反应（PCR）对错误校正的分析表明，老年组的错误校正能力下降。这种效应仅在超秒级间隔和大正向阶跃变化的试验中出现。总体而言，这些结果支持以下假设：老年组在亚秒级范围内的感觉运动同步得以维持，但在超秒级范围内的同步准确性和错误校正能力在50岁左右就开始下降，这表明这些指标适用于早期检测运动系统与年龄相关的变化。
