Sensory recruitment by working memory: neuronal basis and neural circuitry

工作记忆的维持是在学习过程中有序追求目标的基础。 面对无关的、分散注意力的刺激。前额叶和视觉区域都被认为 有助于维持工作记忆中的项目，但确切的性质， 这些领域之间的相互作用还有待于研究其因果关系。这项建议 结合了单个单位活动和局部场电位的神经生理学记录 通过对前额叶皮层的药理学操作， 记忆驱动的神经活动变化和视觉区域内的同步。当地 场电位允许检查振荡特征和锁相， 他们对视觉表现力的贡献。这种振荡的变化 最近已经证明，相对于正在进行的振荡， 来反映工作记忆的内容。本提案中的实验将1）因果地 测试前额叶皮层是否驱动后部区域的这些振荡，2）构建一个 模型和测试它的预测，这种自上而下的信号如何驱动振荡变化，3） 确定这些变化如何改变视觉刺激的表现， 工作记忆的维持，以及4）建立这些变化之间的关系， 振荡功率和尖峰时间对刺激影响行为的能力的影响。这 对工作记忆神经机制的基本理解 维护将反过来提供洞察工作记忆障碍的基础， 精神分裂症、注意力缺陷多动障碍和帕金森氏症 疾病

Working memory maintenance is fundamental for the orderly pursuit of goals in the face of irrelevant, distracting stimuli. Both prefrontal and visual areas are thought to contribute to the maintenance of items in working memory, but the exact nature of the interaction between these areas has yet to be causally examined. This proposal combines neurophysiological recordings of single unit activity and local field potentials with pharmacological manipulations of the prefrontal cortex, to determine its contribution to memory-driven changes in neural activity and synchrony within visual areas. Local field potentials allow the examination of oscillatory signatures and phase locking, and their contribution to the strength of the visual representation. Such changes in oscillatory power and the timing of spikes relative to ongoing oscillations have recently been shown to reflect the content of working memory. Experiments in this proposal will 1) causally test whether prefrontal cortex drives these oscillations in posterior areas, 2) construct a model and test its predictions for how this top-down signal drives oscillatory changes, 3) determine how these changes alter the representation of visual stimuli presented during working memory maintenance, and 4) establish the relationship of these changes in oscillatory power and spike timing to the stimulus’ ability to impact behavior. This fundamental understanding of the neural mechanisms contributing to working memory maintenance will in turn provide insight into the basis for working memory impairments in disorders such as schizophrenia, attention deficit hyperactivity disorder, and Parkinson’s disease.