Changes in Brain Signal Variability as a Function of Learning and Expertise in Lexical Decision Making

在将大脑信号与认知联系起来时，假设行为过程将激活大脑的关键区域。与计算机非常相似，当需要它支持的进程时，该区域为“开”，当不需要该进程时，该区域为“关”。大脑组织的一些关键特征表明，我们需要重新考虑这一想法。研究人员已经证明，大脑依靠活动性和变异性来确保最佳功能，而且大脑区域一直产生不同的信号(即使在计算机类比中，它们处于关闭状态)。事实上，大脑信号的可变性使人们能够对环境需求做出快速而灵活的反应。与其把计算机想象成一个不断运动的系统，不如把大脑想象成一个不断运动的系统，而不是一台能开关机的计算机，而是把变化性看作是让这个系统能够轻松地从一个网络移动到另一个网络的动能。 是什么决定了大脑的可变性？一些科学家认为，它代表了信息处理能力--本质上，它告诉我们大脑支持任务执行的能力。让大脑更有能力支持一项任务的一种方法是，通过投入时间来练习，学习非常好地完成这项任务。我的研究检查了学习过程中的大脑信号，同时人们练习快速做出单词-非单词的决定。我预计，在实践的早期，随着人们探索不同的快速反应方式，大脑的变异性将会增加。在人们确定了最好的应对方式后，变异性将会降低(但保持在练习之前的较高水平)。我还将在专业知识的背景下研究大脑的可变性。有竞争力的拼字游戏玩家是做出单词-非单词决定的专家，我预计他们的大脑会比非专家产生更多的可变信号来支持这项任务。未来，这项研究计划将使科学家能够利用大脑的变异性来了解处理能力，并可能使我们能够帮助人们更好地学习。

In relating brain signals to cognition, the assumption is that behavioural processes will activate key regions of the brain. Much like a computer, the region is 'on' when the process it supports is required, and 'off' when the process is not required. Some critical features of brain organization suggest that we need to rethink this idea. Researchers have shown that the brain relies on both activity and variability to ensure optimal function, and that brain regions produce variable signal at all times (even when they are 'off' in the computer analogy). In fact, brain signal variability allows people to respond quickly and flexibly to environmental demands. Instead of a computer that turns on and off, think of the brain as a system in constant motion, and think of variability as the kinetic energy that allows this system to move easily from one network to another. What determines brain variability? Some scientists suggest that it represents information processing capacity - essentially, that it tells us about the capability of a brain to support task performance. One way to make the brain more capable of supporting a task is to learn to do that task exceptionally well, by devoting time to practice. My research examines brain signal during the learning process, while people practice making quick word-nonword decisions. I expect that early in practice, brain variability will increase as people explore different ways to respond quickly. Variability will then decrease after people settle on the best way to respond (but stay higher than before practice). I will also look at brain variability in the context of expertise. Competitive Scrabble players are experts at making word-nonword decisions, and I expect their brains to produce more variable signal to support this task than non-experts. In the future, this research program will enable scientists to use brain variability to understand processing capacity, and possibly allow us to help people learn better.