Faßbender Laura, Falck Johannes, López Francisco M, Shing Yee Lee, Triesch Jochen, Schwarzer Gudrun
Department of Psychology, Faculty of Psychology and Sport Science, Justus Liebig University, Otto-Behaghel-Str. 10F, 35394, Gießen, Germany.
Department of Psychology, Goethe University Frankfurt am Main, Frankfurt am Main, Germany.
Sci Rep. 2025 Jan 29;15(1):3699. doi: 10.1038/s41598-025-87441-6.
Adapting movements to rapidly changing conditions is fundamental for interacting with our dynamic environment. This adaptability relies on internal models that predict and evaluate sensory outcomes to adjust motor commands. Even infants anticipate object properties for efficient grasping, suggesting the use of internal models. However, how internal models are adapted in early childhood remains largely unexplored. This study investigated a naturalistic force adaptation task in 1.5-, 3-year-olds, and young adults. Participants opened a drawer with temporarily increased resistance, creating sensory prediction errors between predicted and actual drawer dynamics. After perturbation, all age groups showed lower peak speed, longer movement time, and more movement units with trial-wise changes analyzed as adaptation process. Results revealed no age differences in adapting peak speed and movement units, but 1.5- and 3-year-olds exhibited higher trial-to-trial variability and were slower in adapting their movement time, although they also adapted their movement time more strongly. Upon removal of perturbation, we found significant aftereffects across all age groups, indicating effective internal model adaptation. These results suggest that even 1.5-year-olds form internal models of force parameters and adapt them to reduce sensory prediction errors, possibly through more exploration and with more variable movement dynamics compared to adults.
使动作适应快速变化的环境是与动态环境进行交互的基础。这种适应性依赖于内部模型，该模型预测和评估感官结果以调整运动指令。甚至婴儿也会预测物体属性以便有效抓握，这表明他们使用了内部模型。然而，幼儿期内部模型是如何适应的在很大程度上仍未得到探索。本研究调查了1.5岁、3岁儿童和年轻人在一项自然力适应任务中的表现。参与者打开一个阻力暂时增加的抽屉，这在预测的和实际的抽屉动态之间产生了感官预测误差。在受到干扰后，所有年龄组在每次试验中分析适应过程时，都表现出较低的峰值速度、较长的运动时间和更多的运动单元。结果显示，在适应峰值速度和运动单元方面不存在年龄差异，但1.5岁和3岁儿童在每次试验之间表现出更高的变异性，并且在适应运动时间方面较慢，尽管他们在运动时间上的适应性也更强。在去除干扰后，我们发现所有年龄组都有显著的后效，表明有效的内部模型适应。这些结果表明，即使是1.5岁的儿童也能形成力参数的内部模型，并通过更多的探索以及与成年人相比更具变化性的运动动态来调整这些模型，以减少感官预测误差。
