Comparison of cortical mapping rehabilitation procedures for the measurement of motor plasticity in the human brain

我们大脑中的神经元有能力修改它们的连接，这种现象被称为大脑可塑性，它允许学习新的能力，适应不同的环境，在某种程度上，在受伤后恢复。新的神经成像和神经刺激技术的出现对我们对大脑可塑性的认识起到了关键作用。一种名为经颅磁刺激的特殊技术包括刺激大脑中参与运动控制的区域，并记录由这些刺激人工诱发的肌肉收缩。这使我们能够制作一张给定肌肉在大脑中如何表现的“地图”，然后研究这张地图在不同事件发生后如何变化。然而，评估这些变化的范围并了解它们的行为相关性仍然是一个重要的挑战。目前测量可塑性的基本方法的一个例子是，非常不同的事件，如制动和运动训练，往往会导致地图上类似的变化，尽管它们对运动表现的影响明显不同。因此，目前我们不能暗示在大脑中观察到的变化与它们对运动能力的影响之间存在简单的关系。我的研究计划的目标是了解大脑中控制运动的区域的可塑性如何影响运动能力，并确定衡量这种可塑性的最佳方法。由于大脑的可塑性对运动行为既有积极的影响，也有消极的影响，因此更好地理解这一现象并改进其测量方法是至关重要的，因为这种知识将使大脑的可塑性在未来得到可预测的调节。

The neurons in our brain have the ability to modify their connections, a phenomenon termed brain plasticity that allows learning of new abilities, adaptation to different environments and, to some extent, recovery following injury. The emergence of new neuroimaging and neurostimulation techniques has played a pivotal role in the progress of our knowledge of brain plasticity. One particular technique, called transcranial magnetic stimulation, consist of stimulating the areas of the brain involved in movement control and recording the contractions of the muscles that are artificially evoked by those stimulations. This allows us to make a "map" of how a given muscle is represented in the brain, and then to study how this map changes following different events. Assessing the scope of these changes and understanding their behavioural relevance remains, however, an important challenge. One example of the rudimentary nature of current approaches to measuring plasticity is that very different events, such immobilization and motor training, often appear to result in similar changes in the maps, despite obvious differences in their effects on motor performance. Currently, therefore, we cannot imply a simple relationship between changes observed in the brain and their effect on motor capacities. The goal of my research program is to understand how plasticity in areas of the brain that control movement affects motor capacities, and to identify the optimal way to measure this plasticity. As brain plasticity can have both positive and negative effects on motor behaviour, it is crucial to gain a better understanding of this phenomenon and to refine its measurement, as this knowledge will allow brain plasticity to be predictably modulated in the future.