ENCODING MOVEMENT KINEMATICS IN THE PREMOTOR CORTEX

描述（改编自申请人的摘要）：心理物理学， 解剖学、电生理学和病变研究支持这一假设 背侧启动子皮层（PMd）在脑内的运动中起着重要的作用。 将视觉信息转化为运动指令。 更具体的 这一假设的表述是，PMd负责 将视觉（或其他感官刺激）信息非标准映射到 运动指令，也就是说，当指导动作的刺激不是 行动的目标。 使用慢性单单位记录研究 行为灵长类动物，提出了四个具体的目的，以测试具体的 关于PMd神经元放电如何编码和转换的假设 将视觉空间信息转化为动作。 第一个特定目标测试的假设，即细胞的轨迹 定向调谐表示在PMd期间对PMd神经元的最佳刺激。 提示周期，并且该轨迹独立于复杂的 视觉空间刺激 PMd神经元的放电将在一段时间内进行研究。 追踪任务，当目标在提示期间的运动模仿 细胞的首选方向轨迹，当方向和速度 提示中所呈现的信息与方向无关， 和即将到来的运动的速度。 第二个具体目标测试的假设，即属性的 提示时段中的定向调谐提供了一种机制， 一个方向的刺激转化为另一个方向的运动 方向 PMd细胞的定向调谐将在一个 当动物执行视觉重定向时的追踪任务 任务 第三个具体目标检验的假设，即方向和 在PMd细胞放电的速度编码被修改时，动物 学习新的视觉映射。 将在开始前对PMD放电进行评估， 在视觉转换之后，需要动物映射 视觉空间刺激到新运动的方向和速度 方向或运动速度。 第四个具体目标测试的假设，时间顺序和 PMd细胞放电中特定参数的编码依赖于 在手臂运动期间呈现的视觉信息的时间上。 PMD神经元将在以下范例中进行研究：1）操纵信息 关于即将到来的运动的方向和幅度，以及2）操纵 关于运动方向和速度的信息。 总的来说，这些研究将提供深入了解神经机制， PMd是视觉空间信息映射到运动的基础。

DESCRIPTION (adapted from applicant's abstract): Psychophysical, anatomical, electrophysiological, and lesion studies support the hypothesis that the dorsal promotor cortex (PMd) plays an important role in the transformation of visual information into motor commands. A more specific formulation of this hypothesis is that the PMd is responsible for non-standard mapping of visual (or other sensory stimuli) information into motor commands, that is, when the stimulus guiding an action is not the target of the action. Using chronic single unit recording studies in behaving primates, four Specific Aims are proposed to test specific hypotheses on how the discharge of PMd neurons encodes and transforms visuospatial information into movements. The first Specific Aim tests the hypothesis that the trajectory of a cell's directional tuning represents an optimal stimulus for a PMd neuron during the cue period and that this trajectory is independent of complex visuospatial stimuli. The discharge of PMd neurons will be studied during a pursuit tracking task when the target movement during the cue period mimics a cell's preferred direction trajectory and when the direction and velocity of the information presented in the cue are dissociated from the direction and velocity of the upcoming movement. The second specific aim tests the hypothesis that the properties of the directional tuning in the cue period provide a mechanism to map a visual stimulus presented in one direction into a movement made in another direction. The directional tuning of PMd cells will be evaluated during a pursuit tracking task when the animal performs a visuomotor redirection task. The third specific aim tests the hypothesis that the directional and velocity coding in the discharge of PMd cells is modified when the animal learns a new visuomotor mapping. PMd discharge will be evaluated before and after visuomotor transformations that require the animal to map the direction and velocity of visuospatial stimuli into novel movement directions or movement velocities. The fourth specific aim tests the hypothesis that the temporal ordering and encoding of specific parameters in the discharge of PMd cells is dependent on the timing of the visuomotor information presented during arm movements. PMd neurons will be studied in paradigms that 1) manipulate the information about the direction and amplitude of the upcoming movement and 2) manipulate the information about the direction and velocity of the movement. Overall, these studies will provide insights into the neuronal mechanisms in the PMd underlying the mapping of visuospatial information into movements.