Cortical Substrates of Working Memory for Visual Motion

描述（由申请人提供）：短暂保留视觉信息的能力是成功执行视觉引导行为的基础。这是一个更新的应用程序，以研究电路底层的主动维护的感觉表征，即感觉工作记忆。最重要的目标是在传统上与视觉运动处理相关的皮质区域和与工作记忆和视觉引导行为的认知控制相关的区域之间提供联系。我们将重点关注运动加工的皮层MT和MST区域，以及与工作记忆和认知控制密切相关的前额叶皮层（RFC）。我们最近的研究表明，在视觉运动任务的记忆过程中，MT神经元携带与记忆相关的信号，并受到行为任务需求的影响。PFC的记录还揭示了与记忆相关的活动，以及受动物行为状态强烈调节的活动。此外，他们揭示了选择性视觉运动的反应，类似于MT和MST区域神经元的特征。在相同的行为任务中，运动处理区和PFC中存在记忆信号和感觉反应的相似性表明这两个区域之间存在潜在的功能联系，并且它们参与了为视觉运动记忆能力服务的电路。在下一个资助期内，我们将研究最近在MT (Aim 1.1), MST （Aim 1.2）和PFC （Aim 2）区域发现的与记忆相关的定向运动信号的性质。我们还将关注两个区域之间的相互作用，通过确定PFC是否是记忆信号的来源和任务需求的调制，记录在MT和MST中（目标3）。在所有的实验中，我们将使用一个任务，让猴子比较两个被记忆延迟分开的移动刺激的方向。我们将把单个神经元的活动记录和局部场电位、微刺激和可逆失活与视觉工作记忆的心理物理测量相结合。这些研究将揭示PFC和皮层处理工作记忆中使用的感觉信号的神经元的参与，以及它们协调活动以支持成功执行记忆任务的方式。对短期感觉信息存储的神经回路的了解将有助于理解和治疗以工作记忆障碍为特征的疾病，如阿尔茨海默氏症、帕金森病和精神分裂症。

DESCRIPTION (provided by applicant): The ability to briefly retain visual information is fundamental to successfully executing visually guided behaviors. This is a renewal application to study the circuitry underlying the active maintenance of sensory representation, i.e. sensory working memory. The overriding goal is to provide a link between cortical areas traditionally associated with processing of visual motion and regions identified with working memory and cognitive control of visually guided behaviors. We will focus on cortical areas MT and MST, important for motion processing, and on prefrontal cortex (RFC) strongly associated with working memory and cognitive control. Our recent work revealed that during the performance of a memory for visual motion task, MT neurons carry memory-related signals and are affected by the demands of the behavioral task. Recordings from PFC also revealed memory related activity and of activity strongly modulated by the behavioral state of the animal. Furthermore, they revealed responses selective for visual motion, similar to those characteristic of neurons in areas MT & MST. The presence of memory signals and the similarity of sensory responses in motion processing areas and in PFC during the same behavioral task suggests a potential functional link between these 2 regions and their participation in the circuitry sub-serving the ability to remember visual motion. During the next grant period we will examine the nature of recently discovered memory-related directional motion signals in areas MT (Aim 1.1), MST (Aim 1.2) and PFC (Aim 2). We will also focus on the interactions between the 2 regions by determining whether PFC is a source of memory signals and modulation by task demands, recorded in MT and MST (Aim 3). For all experiments, we will use a task in which the monkeys compare the directions of 2 moving stimuli separated by memory delay. We will combine recordings of activity of single neurons and local field potentials, microstimulation and reversible inactivation with psychophysical measures of visual working memory. These studies will shed light on the involvement of neurons in PFC and in cortical areas processing sensory signals used in working memory and the way they coordinate their activity to support successful execution of memory tasks. The knowledge of the neural circuitry underlying short-term storage of sensory information will contribute to the understanding and treatment of diseases characterized by working memory impairments, such as Alzheimer's, Parkinson's and Schizophrenia.