Virtual environments have been widely utilized in motor neuroscience and rehabilitation as they afford tight control of sensorimotor conditions and readily afford visual and haptic manipulations. However, typically studies have only examined performance in the virtual testbeds, without asking how performance in the virtual environment compares to behavior in the real world. To test that, this study compared throwing in a virtual and real set-up where the task parameters were precisely matched. Even though the virtual task only required a single-joint arm movement, similar to many simplified movement assays in motor neuroscience, throwing accuracy and precision was significantly better in the real task; only after three days did the performance reach same levels. To gain more insight into the structure of the learning process, movement variability was decomposed into deterministic and stochastic contributions to distinct stages of learning by using the TNC method: Tolerance was optimized first and was higher in the virtual environment, suggesting that more familiarization and exploration is needed in the virtual task. Covariation and noise showed far fewer and only contributes late in the real task, indicating that subjects reached the stage of fine-tuning of variability only in the real task. These results showed that while the tasks were precisely matched, the simplified movements in the virtual environment required more practice to be successful. These findings resonate with the reported problems in transfer of therapeutic benefits from virtual to real environments and alert that the use of virtual environments in research and rehabilitation needs more caution.

中文翻译：

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回到现实：简化的虚拟和真实投掷任务中学习策略的差异

虚拟环境已广泛应用于运动神经科学和康复领域，因为它们可以严格控制感觉运动条件并轻松进行视觉和触觉操作。然而，研究通常只检查虚拟测试台中的性能，而没有询问虚拟环境中的性能与现实世界中的行为相比如何。为了测试这一点，这项研究比较了虚拟和真实的设置，其中任务参数精确匹配。尽管虚拟任务只需要单关节手臂运动，与运动神经科学中的许多简化运动测定类似，但投掷准确性和精确度在真实任务中明显更好；三天后，性能才达到相同水平。为了更深入地了解学习过程的结构，通过使用 TNC 方法，运动变异性被分解为对不同学习阶段的确定性和随机贡献：首先优化了耐受性，并且在虚拟环境中更高，这表明更多的熟悉和探索虚拟任务中需要。协变和噪声显示出少得多，并且仅在实际任务的后期起作用，表明受试者仅在实际任务中达到了变异性微调的阶段。这些结果表明，虽然任务是精确匹配的，但虚拟环境中的简化动作需要更多的练习才能成功。这些发现与所报道的将治疗效果从虚拟环境转移到真实环境的问题产生了共鸣，并提醒人们在研究和康复中使用虚拟环境需要更加谨慎。