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改变它们之间的联系，这种现象被称为大脑可塑性，它可以让我们学习新的能力，适应不同的环境，在某种程度上，还可以让我们在受伤后恢复过来。新的神经成像和神经刺激技术的出现在我们对大脑可塑性知识的进步中发挥了关键作用。有一种特殊的技术被称为经颅磁刺激，它包括刺激与运动控制有关的大脑区域，并记录由这些刺激人工引起的肌肉收缩。这使我们能够绘制出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后是如何变化的。然而，评估这些变化的范围和理解它们的行为相关性仍然是一个重要的挑战。当前测量可塑性方法的一个基本性质的例子是，非常不同的事件，如固定和运动训练，通常会导致地图上类似的变化，尽管它们对运动表现的影响有明显差异。因此，目前我们还不能在观察到的大脑变化和它们对运动能力的影响之间建立简单的关系。我的研究项目的目标是了解控制运动的大脑区域的可塑性是如何影响运动能力的，并确定衡量这种可塑性的最佳方法。由于大脑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至关重要，因为这些知识将使大脑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.