A hierarchical system for learning and control

即使是最简单的动作也会被大脑中的多个系统监控和评估。例如，如果我们试图拿起一杯咖啡，但由于某种原因失败了，我们需要一个神经系统来识别这一点，并生成一个学习信号，用于修改随后的行为。然而，这并不是我们在伸手去拿一杯咖啡时可能遇到的唯一类型的错误。我们不知道的是，运动计划--大脑向运动系统发出的执行运动的一组指令--可能包含错误。此外，运动计划中的错误可能是由环境中的意外变化引起的-想象一下，咖啡杯的平衡性很差，当我们伸手去拿咖啡时，咖啡杯开始打滑。这些类型的错误-计划中的错误和/或由环境中的意外变化引起的错误需要在运动本身中迅速调解，以便我们成功地实现我们的运动目标。最近，我提出了分层错误处理假说，该假说指出大脑中有两个不同的错误处理系统：一个负责评估我们行动的成功或失败的系统，以及一个负责解决运动计划中的错误的系统。我的研究小组最近的一系列研究支持等级假说。总之，结果表明，大脑额叶中央部分的学习系统在评估运动输出中起着关键作用。现有的实验证据也支持分层假设，因为它证明了大脑后部区域的错误系统在解决正在进行的运动中的初始运动计划中的错误中的作用。形成这一建议的基础上的研究，旨在进一步发展的层次假设，确定进一步的神经标记的错误评估和检查其对行为的影响。此外，我希望改善的理论框架，这是分层假设的基础。重要的是，这项研究将进一步加深我们对学习如何在神经水平上发生的理解，从而提供科学界和普通大众感兴趣的结果。

Even the simplest of movements are monitored and evaluated by multiple systems within the brain. For instance, if we try to pick up a cup of coffee and fail for some reason, we need a neural system that can identify this and generate a learning signal that would be used to modify subsequent behaviour. However, this is not the only type of error we might encounter while reaching for a cup of coffee. Unbeknownst to us, the motor plan - the set of instructions that the brain issues to the motor system to carry out the movement - may contain errors. Additionally, errors in the motor plan may be brought about by unexpected changes in the environment - imagine the cup of coffee is poorly balanced and that it begins to slip as we reach for it. These types of errors - errors in planning and/or errors brought about by unexpected changes in the environment need to be rapidly mediated within the movement itself in order for us to successfully achieve our movement goal. Recently, I have proposed the hierarchical error processing hypothesis which states that there are two distinct error processing systems in the brain: a system that is responsible for evaluating the success or failure of our actions, and a system that is tasked with resolving errors in the motor plan within the movement. A series of recent studies by my research group supports the hierarchical hypothesis. In sum, the results demonstrate that a learning system within frontal-central parts of the brain plays a key role in the evaluation of motor output. Existing experimental evidence also supports the hierarchical hypothesis as it demonstrates the role of error systems in posterior regions of the brain in the resolution of errors in the initial motor plan within an ongoing movement. The research that forms the basis of this proposal seeks to further develop the hierarchical hypothesis by identifying further neural markers of error evaluation and examining their impact on behaviour. Further, I hope to improve the theoretical framework which underlies the hierarchical hypothesis. Importantly, the proposed research will further our understanding of how learning occurs at the neural level, thus providing results which will be of interest to the scientific community and the general population.