Cortical Substrates of Working Memory for Visual Motion

描述(申请人提供)：本项目的目的是研究 视觉运动加工和暂时性存储的神经机制 灵长类皮质中的信息。我们将检验这一假设，即MT区，一个 专门用于分析视觉运动的中层皮质区域，也 参与此信息的短期保留。我们还将确定 这种参与是否通过MT与 前额叶皮质中的神经元，人们普遍认为该区域在 对感觉信息的短期保留。为了实现这一目标，我们将 利用MT区的视网膜复制，使用一个行为任务，在 这些猴子被要求记住一个单词中呈现的运动方向 空间位置，并将其与稍后呈现的另一个方向进行比较 时间在不同的空间位置。这将使我们能够单独检查 在编码、存储和存储过程中发生的神经过程 工作记忆任务的提取/比较阶段。我们将使用这个 心理物理实验中的行为范式，旨在确定 记住的刺激方向的性质。我们也会从单MT开始录制。 在这项任务执行过程中的神经元。此外，我们将申请 运动中生理定位定向柱的微刺激 方向性信息的存储周期。相同的行为任务将 也可以在从前额叶皮质的区域进行记录时使用， 与MT区互连，先前显示为在电路中发挥作用 亚服务于感官信息的临时存储。最后，我们将检查 前额叶皮质对MT神经元活动的影响及其在脑内的作用 工作记忆任务的执行情况。这将通过可逆的方式实现。 前额叶皮质相关区域失活及MT记录 在任务执行过程中的神经元。这些研究将提供新的 关于保留能力背后的皮质机制的信息 有关刺激运动的信息。

DESCRIPTION (Provided by applicant): This project is aimed at the study of the neural mechanisms underlying processing and temporary storage of visual motion information in primate cortex. We will test the hypothesis that area MT, a mid-level cortical region specialized for the analysis of visual motion, also takes part in short-term retention of this information. We will also determine whether this participation is accomplished by the active connection of MT with neurons in prefrontal cortex, a region widely believed to play a key role in short-term retention of sensory information. To accomplish this goal we will take advantage of the retinotopy of area MT and use a behavioral task in which the monkeys are required to remember the direction of motion presented in one spatial location and compare it with another direction presented at a later time in a different spatial location. This will allow us to separately examine the neural processes that take place during encoding, storage and retrieval/comparison phases of the working memory task. We will use this behavioral paradigm in psychophysical experiments aimed at determining the nature of the remembered stimulus direction. We will also record from single MT neurons during the performance of this task. Furthermore, we will apply microstimulation of physiologically identified directional columns in MT during the period of storage of directional information. The same behavioral task will also be used during recordings from a region in prefrontal cortex, interconnected with area MT, previously shown to play a role in the circuitry sub-serving temporary storage of sensory information. Finally, we will examine the contribution of prefrontal cortex to the activity of MT neurons and to the performance of the working memory task. This will be achieved by reversibly inactivating the relevant region of prefrontal cortex and recording from MT neurons during the performance of the task. These studies will provide new information about the cortical mechanisms underlying the ability to retain information about stimulus motion.