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：在谈话中，我们被一个明显的外部信号（“小说”）打断，例如窗户被打破。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。这一提议验证了一个理论，即WM下降的一个原因是显著刺激激活了大脑的运动停止网络，而这个网络对当前活跃的运动和非运动皮质内容物具有全局影响。根据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，通过大脑的全球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下核（STN）实现，c) STN的激活导致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）部分由丘脑皮质驱动维持，因此存在暂时中断，表现为WM减少。该模型的验证对于更好地理解认知心理学中停止与WM之间的关系具有深远的意义；为了更好地理解PD的“过度停止”状态与认知不灵活性之间的关系，以及为了推进与精神病学相关的分心新理论。我们在PD患者和健康志愿者中测试了该模型。在PD患者中，我们将研究停止如何影响WM，同时记录植入STN电极的局部场电位和额叶皮质的头皮脑电图。我们预计，STN中停止诱导的活动将与皮层WM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，我们将使用经颅磁刺激运动皮层作为替代探针的全球STN停止信号。我们期望通过这种方法测量的全局运动抑制程度与停止信号和小说引起的WM的衰减相对应。

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.