AG Allgemeine und Biologische Psychologie, Philipps-Universität Marburg, Marburg, Germany.
Center for Mind, Brain and Behavior, Marburg, Germany.
J Neurophysiol. 2023 Mar 1;129(3):717-732. doi: 10.1152/jn.00419.2022. Epub 2023 Feb 15.
Motor adaptation maintains movement accuracy. To evaluate movement accuracy, motor adaptation relies on an error signal, generated by the movement target, while suppressing error signals from irrelevant objects in the vicinity. Previous work used static testing environments, where all information required to evaluate movement accuracy was available simultaneously. Using saccadic eye movements as a model for motor adaptation, we tested how movement accuracy is maintained in dynamic environments, where the availability of conflicting error signals varied over time. Participants made a vertical saccade toward a target (either a small square or a large ring). Upon saccade detection, two candidate stimuli were shown left and right of the target, and participants were instructed to discriminate a feature on one of the candidates. Critically, candidate stimuli were presented sequentially, and saccade adaptation, thus, had to resolve a conflict between a task-relevant and a task-irrelevant error signal that were separated in space and time. We found that the saccade target influenced several aspects of oculomotor learning. In presence of a small target, saccade adaptation evaluated movement accuracy based on the first available error signal after the saccade, irrespective of its task relevance. However, a large target not only allowed for greater flexibility when evaluating movement accuracy, but it also promoted a stronger contribution of strategic behavior when compensating inaccurate saccades. Our results demonstrate how motor adaptation maintains movement accuracy in dynamic environments, and how properties of the visual environment modulate the relative contribution of different learning processes. Motor adaptation is typically studied in static environments, where all information that is required to evaluate movement accuracy is available simultaneously. Here, using saccadic eye movements as a model, we studied motor adaptation in a dynamic environment, where the availability of conflicting information about movement accuracy varied over time. We demonstrate that properties of the visual environment determine how dynamic movement errors are corrected.
运动适应保持运动精度。为了评估运动精度，运动适应依赖于运动目标产生的误差信号，同时抑制来自附近不相关物体的误差信号。以前的工作使用静态测试环境，其中评估运动精度所需的所有信息都是同时可用的。使用扫视眼动作为运动适应的模型，我们测试了在动态环境中如何保持运动精度，在这种环境中，随时间变化，冲突的误差信号的可用性也在变化。参与者进行垂直扫视朝向目标（小方块或大环）。扫视检测后，目标的左右两侧会显示两个候选刺激，参与者需要在其中一个候选刺激上识别一个特征。关键的是，候选刺激是顺序呈现的，因此，扫视适应必须解决空间和时间上分离的任务相关和任务无关的误差信号之间的冲突。我们发现，扫视目标影响眼动学习的几个方面。在小目标存在的情况下，扫视适应基于扫视后第一个可用的误差信号评估运动精度，而不考虑其任务相关性。然而，大目标不仅在评估运动精度时允许更大的灵活性，而且在补偿不准确的扫视时促进了策略行为的更强贡献。我们的结果表明运动适应如何在动态环境中保持运动精度，以及视觉环境的特性如何调节不同学习过程的相对贡献。运动适应通常在静态环境中进行研究，在这种环境中，评估运动精度所需的所有信息都是同时可用的。在这里，我们使用扫视眼动作为模型，研究了动态环境中的运动适应，在这种环境中，关于运动精度的冲突信息的可用性随时间变化。我们证明了视觉环境的特性决定了如何纠正动态运动误差。
