Sensory recruitment by working memory: neuronal basis and neural circuitry

工作记忆的维持是有序追求工作目标的基础 面对无关紧要、令人分心的刺激。前额叶和视觉区域都被认为是 有助于维护工作记忆中的项目，但 这些地区之间的相互作用尚未得到因果关系的检验。这项建议 结合单个单位活动和局部场电位的神经生理学记录 通过对前额叶皮质的药物处理，来确定它的作用 到记忆驱动的神经活动变化和视觉区域内的同步性。本地 场势允许检查振荡信号和锁相，以及 他们对视觉表现的力量做出了贡献。这样的变化是振荡的 与持续振荡相关的功率和尖峰时间最近已经显示出来 以反映工作记忆的内容。这项提议中的实验将有1)因果关系 测试前额叶皮质是否驱动后部区域的这些振荡，2)构建一个 对这种自上而下的信号如何驱动振荡变化的预测进行建模和测试，3) 确定这些变化如何改变在以下过程中呈现的视觉刺激的表示 工作记忆的维护，以及4)建立这些变化在 振荡功率和尖峰时间与刺激影响行为的能力有关。这 对影响工作记忆的神经机制的基本理解 维护将反过来提供对工作记忆损害的基础的洞察 精神分裂症、注意力缺陷多动障碍和帕金森氏症等疾病 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.