Effects of transcranial direct current stimulation on cortical and subcortical persistent activity

根据计划和目标指导我们的对策的能力是人类行为的一个基本方面。工作记忆（WM）-暂时保留信息的能力-例如当一个人记住一个想要拨打的电话号码时，是认知研究最多的方面之一。前额叶和后顶叶皮层这两个大脑区域与WM的表现关系最为密切。非侵入性的实验技术，允许大脑活动的临时修改有能力大大增加我们的WM的理解，因为它们允许在特定的大脑区域的活动和WM能力之间建立直接的关系。经颅直流电刺激（tDCS）是一种安全、无创的脑刺激方法，正在迅速普及。在这项技术中，微弱的电流被施加到头部表面，这被认为会导致大脑兴奋性的微妙，持久的变化。前额叶和顶叶皮层的tDCS已被证明会影响人类的WM表现，但由于缺乏tDCS的动物模型，我们对负责这些认知变化的大脑活动变化的理解受到限制。非人类灵长类动物可以很容易地被训练来执行WM任务，并且具有与人类相似的皮层区域。本研究的目的是通过结合tDCS和记录执行WM任务的恒河猴前额叶和后顶叶皮层的脑活动来促进我们对tDCS对脑活动影响的理解。

The ability to guide our responses on the basis of plans and goals is a fundamental facet of human behaviour. Working memory (WM) - the ability to temporarily retain information- such as when one holds in mind a phone number one wishes to dial, is one of the most studied aspects of cognition. Two brain areas, the prefrontal and posterior parietal cortex, have been most closely linked to WM performance. Non-invasive experimental techniques that allow temporary modifications of brain activity have the capability to add greatly to our understanding of WM, since they allow establishment of a direct relationship between activity in a particular brain area and WM ability. Transcranial direct current stimulation (tDCS) is a safe, non-invasive method of brain stimulation that is rapidly gaining in popularity. In this technique, weak electrical currents are applied to surface of the head, which are believed to lead to subtle, long-lasting changes in excitability of the brain. tDCS of both prefrontal and parietal cortex has been shown to influence WM performance in humans but our understanding of the changes in brain activity responsible these cognitive changes is limited by our lack of animal models of tDCS. Non-human primates can be readily trained to perform WM tasks, and have similar cortical areas to humans. The objective of this research is to advance our understanding of the effects of tDCS on brain activity by combining tDCS and recordings of brain activity in the prefrontal and posterior parietal cortex of rhesus macaques performing a WM task.