Sensorimotor interactions following callosotomy

这项拟议的研究关注的是人们如何选择、计划和产生协调的行为。许多熟练的行为都需要两只手的动作相结合，才能达到共同的目标。然而，在许多动作中，两只手可能进行基本独立的动作，例如，当一只手拿着电话，另一只手使用计算机鼠标时。无论手是用来完成一个共同的动作，还是从事不同的任务，这些动作都有基本的限制，这表明在控制的计划和执行阶段都存在不同程度的相互作用。对分裂脑患者的研究为研究相对孤立的每个大脑半球的运作提供了一个独特的机会。拟议的实验提供了一种程序性的尝试，以表征发生反应组件整合的表示水平。首先，研究了运动的时间成分。神经学上正常的个体在产生双手动作时表现出强烈的时间耦合模式。这些现象是在大脑分裂的个体中观察到的吗？如果是的话，其方式类似于当两个大脑半球相连时观察到的现象？其次，对左手和右手动作的空间分量和力分量的交互作用进行了评估。第三，先前的结果表明，当两只手被用于不同的任务时，共享执行系统的存在限制了性能。这一局限性即使在骨痂切开术后也能观察到。一系列新的实验将严格评估这一假设。在一段时间内，这些研究应该会为协调行为的心理和神经机制提供重要的见解。

The proposed research is concerned with how people select, plan, and produce coordinated behavior. Many skilled behaviors require that the movements of the two hands be integrated in order to achieve a common goal. However, in many actions, the two hands may be engaged in essentially independent actions such as when holding a telephone with one hand and using a computer mouse with the other. Whether the hands are used to complete a common action or are engaged in different tasks, there are fundamental constraints on these movements, indicating various levels of interaction in both planning and execution stages of control. The study of split-brain patients provides a unique opportunity to study the operation of each cerebral hemisphere in relatively isolation. The proposed experiments provide a programmatic attempt to characterize the levels of representation at which integration of response components occurs. First, the temporal components of the movements are examined. Neurologically normal individuals show strong patterns of temporal coupling when producing bimanual movements. Are these phenomena observed in individuals with split-brains and if so, in a manner similar to that observe when the two hemisphere are connected? Second, the interaction of the spatial and force components of left- and right=handed movements is evaluated. Third, previous results have suggested that the existence of a shared implementation system limits performance when the two hands are used in distinct tasks. This limitation is observed even after callosotomy. A series of new experiments will rigorously assess this hypothesis. As a while, the studies should provide important insights into the psychological and neural mechanisms of coordinated behavior.