How stopping movement affects working memory

描述（由申请人提供）：我们都经历过这样的情况，在谈话过程中，我们被一个突出的外部信号（“小说”）打断，例如打破窗户。我们很快就适应了小说，然后发现我们的思路，或者更具体地说，我们的工作记忆（WM）被打断了。该提议测试了这样一种理论：WM减少的一个原因是显着刺激激活了大脑的运动停止网络，而该网络对当前活跃的运动和非运动皮质内容具有全局影响。基于我们发表的和初步的数据，我们提出了以下神经系统模型：a）小说作为停止信号，通过大脑的全局停止网络产生快速的运动停止，B）该网络通过基底神经节的丘脑底核（subthalamic nucleus，简称STN）实现，c）STN的激活导致对丘脑皮质驱动的广泛抑制脉冲，d）由于所有运动和非运动表征（包括WM）部分由丘脑皮层驱动维持，因此存在暂时中断，表现为WM减少。验证这一模型对于更好地理解认知心理学中停止与工作记忆之间的关系、更好地理解PD中的"过度停止"状态与认知能力之间的关系以及提出与精神病学相关的注意力分散新理论具有深远的意义。我们在PD患者和健康志愿者中测试该模型。在帕金森病患者中，我们将研究停止如何影响WM，同时我们记录了从植入的双极电极和从额叶皮层的头皮EEG的局部场电位。我们预计停止诱导的STN活动将与WM皮质标记物的减少相对应，从而将假定的全局STN停止信号与WM的减少联系起来。在健康志愿者中，我们将使用运动皮层的经颅磁刺激作为全局停止信号的替代探针。我们期望用这种方法测量的整体运动抑制的程度将与停止信号以及小说引起的WM的减少相对应。

DESCRIPTION (provided by applicant): We all experience the sort of situation where, during a conversation, we are interrupted by a salient external signal (a 'novel'), e.g. a breaking window. We quickly orient to the novel, and then find that our train of thought, or more specifically our working memory (WM), has been interrupted. This proposal tests the theory that one reason for this WM decrement is because the salient stimulus activates the brain's motor stopping network, and this network has global effects on currently active motor and non-motor cortical contents. Based on our published and preliminary data we advance for the following neural systems model: a) novels act as stop signals, generating a rapid motor stop via the brain's global stopping network, b) this network is implemented via the subthalamic nucleus (STN) of the basal ganglia, c) activation of the STN leads to a widespread pulse of suppression on thalamocortical drive, d) as all motor and non-motor representations (including WM) are partly sustained by thalamocortical drive, there is a temporary interruption which manifests as a WM decrement. Validating this model has far-reaching significance for better understanding the relationship between stopping and WM in cognitive psychology; for better understanding the relation between the 'over-stopped' state in PD and cognitive inflexibility, and for advancing a new theory of distractibility, relevant for psychiatry. We test the model in PD patients and in healthy volunteers. In PD patients we will examine how stopping affects WM while we simultaneously record local field potentials from implanted STN electrodes and scalp EEG from the frontal cortex. We expect that stopping-induced activity in the STN will correspond with reductions in the cortical marker for WM, thus linking the putative global STN stop signal with a decrement in WM. In healthy volunteers we will use Transcranial Magnetic Stimulation of motor cortex as a surrogate probe of the global STN stop signal. We expect that the degree of global motor suppression measured by this method will correspond with the decrement in WM induced by stop signal as well as novels.