School of Psychology, University of Adelaide, Adelaide, South Australia, Australia.
PLoS One. 2019 Sep 12;14(9):e0222219. doi: 10.1371/journal.pone.0222219. eCollection 2019.
Visual and proprioceptive information is used differently at different phases of a reach. The time at which a target perturbation occurs during a reach therefore has a significant impact on how an individual can compensate for this perturbation though online control. With healthy ageing, there are notable changes to both sensory and motor control that impact motor performance. However, how the online control process changes with age is not yet fully understood. We used a target perturbation paradigm and manipulated the time at which a target perturbation occurred during the reach to investigate how healthy ageing impacts sensorimotor control. We measured how the latency of the correction and the magnitude of the corrective response changed with perturbation time and quantified the difference across groups using a percentage difference measure. For both groups, online corrections to early perturbations were more easily accounted for than those to late perturbations, despite late perturbations eliciting faster correction latencies. While there was no group difference in accuracy, older participants were slower overall and produced a correction to a change in target location proportionally less often despite similar correction latencies. We speculate that the differences in the time during the reach that the correction is first identified may explain the differences in correction latencies observed between the perturbation time conditions.
在伸手过程的不同阶段，视觉和本体感觉信息的使用方式不同。因此，目标扰动在伸手过程中发生的时间对个体通过在线控制来补偿这种扰动有很大的影响。随着健康老龄化，感觉和运动控制都会发生显著变化，从而影响运动表现。然而，在线控制过程如何随年龄变化尚不完全清楚。我们使用了目标扰动范式，并在伸手过程中操纵目标扰动发生的时间，以研究健康老龄化如何影响感觉运动控制。我们测量了在扰动时间的影响下，校正的潜伏期和校正幅度如何变化，并使用百分比差异测量来量化组间的差异。对于两个组，早期扰动的在线校正比晚期扰动更容易解释，尽管晚期扰动引发了更快的校正潜伏期。尽管在准确性方面没有组间差异，但老年人整体速度较慢，并且在目标位置发生变化时，校正的比例也较低，尽管校正潜伏期相似。我们推测，在伸手过程中首次识别校正的时间差异可能解释了在扰动时间条件下观察到的校正潜伏期差异。
