APRAXIA--NEURAL REPRESENTATIONS OF LEARNED MOVEMENT

人的左侧大脑半球含有解剖结构 不仅是语言方面的专业，也是更高层次的运动方面的专业 编程。然而，在调查这一事件的性质时，一个主要问题是 这种专门的运动控制系统一直是 获得三维空间中运动的客观测量。 为此，建议进行一连串的调查，全部涉及三项- 一例神经性疾病的三维计算机图形建模与分析 左脑功能衰竭引起的运动(失用) 系统。运动计时中损伤的分析和模拟， 空间关系和联合控制将提供对 左脑大脑半球表征习得的本质， 熟练的动作。调查沿着四条路线进行： 查询： 学习运动的神经表示的分数。替代方案 对失用症基础的模型进行了测试，重点是假设 失用是由于大脑的时空表征被破坏所致 学习到的运动存储在左半球。对……的分级 然后对特定脑部病变引起的这些表现进行调查。 新的时空表征的形成。大脑的形成 在破坏现有时空表示之后，新的时空表示是 通过分析调查两者的恢复模式 失语症受试者的功能及通过对其分级的研究 手势获取过程。 失用症中的运动等价性丧失。破坏的后果 灵活的学习运动的时空表征 通过调查可能的行为损失来探索行为的控制 失用受试者的运动等价性。我们假设失调症患者 受试者，而不是右脑损伤的受试者，将失去 马达等价性带来的对马达行为的灵活控制。 失语症错误的计算机模拟。时空 学习到的运动的表示被用计算机建模，并且 失用受试者通过“损毁”模拟的动作错误 模型中的组件进程。以这种方式，控制过程 在失用症中可能被破坏的东西可以被照亮。 通过洞察学习的表征的本质， 大脑中熟练的运动，补偿其干扰的新方法 中风或其他形式的脑损伤可能会发生。这些研究， 作为一个整体，应该提供对基础的独特见解 失用症，习得性的时空表征的分离， 在特定的脑部损伤后熟练地移动，进入 左脑在高级运动控制中的特殊作用。

The left cerebral hemisphere in man contains anatomic structures specialized not only for language but also for higher-order motor programming. A major problem, however, in investigating the nature of this specialized movement control system has been the difficulty of obtaining objective measurement of movement in three-dimensional space. To this end, a series of investigations are proposed all involving three- dimensional computergraphic modeling and analysis of a neural disorder of movement (apraxia) that results from failure of this left hemisphere system. Analysis and simulations of impairments in movement timing, spatial relations, and joint control will provide unique insight into the nature of the left cerebral hemisphere's representations of learned, skilled movements. The investigation proceeds along four lines of inquiry: Fractional of Neural Representations of Learned Movement. Alternate models of the basis of apraxia are tested, focussing on the hypothesis that apraxia results from destruction of spatiotemporal representations of learned movement stored in the left hemisphere. The fractionation of these representations due to specific brain lesions are then investigated. Formation of New Spatiotemporal Representations. The brain's formation of new spatiotemporal representations after destruction of existing ones is investigated both through the analysis of the pattern of recovery of function in apraxic subjects and through study of the fractionation of the gesture acquisition process. Loss of Motor Equivalence in Apraxia. The consequences of the destruction of spatiotemporal representations of learned movement for the flexible control of behavior are explored by investigating the possible loss of motor equivalence in apraxic subjects. We hypothesize that apraxic subjects, but not subjects with right hemisphere lesions, will have lost the flexible control of motor behavior that motor equivalence entails. Computer Simulations of Apraxic Errors. The spatiotemporal representations of learned movement are computergraphically modeled, and the movement errors that apraxic subjects make simulated by 'lesioning' component processes in the model. In this manner, the control processes that may be disrupted in apraxia can be illuminated. By gaining insight into the nature of the representations of learned, skilled movement in the brain, new ways to compensate for their disruption by stroke or other forms of brain damage can be developed. These studies, taken as a whole, should provide unique insights into the basis of apraxia, the fractionation of spatiotemporal representations of learned, skilled movement following specific brain lesions, and into the specialized role of the left hemisphere for higher order motor control.