ENCODING MOVEMENT KINEMATICS IN THE PREMOTOR CORTEX

了解中枢神经系统在正常和 异常的运动行为将需要破译什么参数， 运动是在哪里，在哪里。 心理物理观察支助 假设到达运动是使用 运动学框架。从运动学上讲，方向、距离、速度和 运动的准确性是将手臂定位在 空间虽然已经研究了运动方向的神经元相关性 并在几个大脑皮层区域，中央 其他手臂运动参数的表示已经收到较少 关注该提案将评估五个问题，重点是编码 灵长类前运动神经元放电的运动学参数。 重点放在确定的贡献和关系 距离、方向、速度和空间精度之间的差异， 三维手臂到达任务。在第一个具体目标中， 运动前神经元的活动对空间准确性的依赖 将对一个运动进行评估。在第二个具体目标中， 跟踪任务将用于剖析出相对重要性， 速度、距离和运动时间对放电的相互作用 前运动皮层细胞的细胞。在第三个具体目标中， 运动幅度的相关性将在一个三维研究 达成任务。 在第四个具体目标中，我们建议系统地 改变视觉反馈，在运动中引入误差。使用 这个复杂的，视觉引导的任务，它将被确定是否 距离和方向的编码保持不变， 视觉“错误”编码在这些细胞的放电中。最后，在 第五个具体目标运动前区皮质被假设为在运动中起作用。 在学习将一个运动与另一个运动相结合的任意关联中的作用 刺激。使用一种需要运动缩放的学习范式 运动学由于反馈的变化，我们建议研究如何适应 移动方向和距离在单个单元水平上被编码。 总的来说，这些研究将更好地定义运动前皮层的作用， 在运动行为中起作用。

Understanding the role of the central nervous system in the normal and abnormal motor behavior will require deciphering what parameters of movement are represented and where. Psychophysical observations support the hypothesis that reaching movements are planned and/or executed using a kinematic framework. Kinematically the direction, distance, velocity and accuracy of a movement are crucial components to positioning the arm in space. While neuronal correlates of movement direction have been studied and described in several cerebral cortical areas, the central representation of other arm movement parameters has received less attention. This proposal will evaluate five issues focused on the encoding of kinematic parameters in the discharge of primate premotor neurons. Emphasis is placed on determining the contributions and relationships between distance, direction, velocity and spatial accuracy in two and three dimensional arm reaching tasks. In the first Specific Aim the dependence of the activity of premotor neurons on the spatial accuracy of a movement will be evaluated. In the second Specific Aim a two dimensional tracking task will be used to dissect out relative importance and interactions between velocity, distance and movement time to the discharge of premotor cortical cells. In the third Specific Aim the neuronal correlates of movement amplitude will be studied in a three dimensional reaching task. In the fourth Specific Aim we propose to systematically alter the visual feedback, introducing errors into the movement. Using this complex, visually guided task, it will be determined whether the encoding of distance and direction remains invariant and whether the visuomotor "errors" are encoded in these cells' discharge. Lastly, in the fifth Specific Aim the premotor cortex has been hypothesized to play a role in learning the arbitrary associations that couple a movement to a stimulus. Using a learning paradigm which requires the scaling of movement kinematics due to a feedback change, we propose to study how adaptation of movement direction and distance is encoded at the single cell level. Overall, these studies will better define the role the premotor cortex plays in motor behavior.