SACCADIC EYE MOVEMENT STUDIES

我们工作的最终目标是了解大脑是如何运作的。我们以动眼肌系统为模型，专注于输出或大脑功能的运动部分。我们最近对扫视眼运动（我们用来“看”我们的视觉世界的快速、步进式扫描眼运动）的研究揭示了扫视是如何被神经扫视生成器编程的新细节。具体来说，我们发现舌下前置核（nph）和Cajal间质核不能提供指定正确眼跳大小的内部控制信号（局部反馈）。神经积分器是一个假设的核，它将速度编码命令转换为眼位放电，从而在数学意义上整合信号。我们还发现nph（假设的神经积分器）产生眼球运动指令信号，以在眼球偏心位置产生稳定的凝视，但不能用于提供眼球位置或眼球速度反馈来控制眼跳轨迹。因此，当前的模型必须修改，以解释我们最近的结果。这些研究是目前常用的基于眼动缺陷的鉴别神经学诊断的基础，也是我们对动眼病过程的理解的基础。此外，它们还可以作为研究中枢神经系统功能更复杂方面的平台，例如运动系统（例如定向时的眼睛和头部）或感觉和运动系统（例如视觉和动眼肌系统）之间的相互作用，以及更抽象的功能，例如注意力和记忆。

The ultimate goal of our work is to understand how the brain functions. We concentrate on the output, or motor portions of brain function, using the oculomotor system as a model. Our recent studies of saccadic eye movements (the quick, step-like scanning eye movements we use to "look at" our visual world) have revealed new details about how saccades are programmed by the neural saccade generator. Specifically, we showed that the nucleus prepositus hypoglossi (nph) and the interstitial nucleus of Cajal cannot provide an internal control signal (local feedback) that specifies the correct saccade size. The neural integrator is an hypothesized nucleus that converts velocity-coded commands into eye-position discharge and thus integrates the signals in a mathematical sense. We also showed that the nph (the putative neural integrator) produces the oculomotor command signals to produce steady gaze at eccentric eye positions but cannot be used to supply eye-position or eye-velocity feedback to control saccade trajectory. Thus, current models must be revised to account for our recent results. These studies are basic to the differential neurological diagnosis based on eye-movement deficits now commonly used as well as to our understanding of oculomotor processes. In addition, they serve as a platform for studies of more complex aspects of central nervous system function, such as the interaction between motor systems (e.g., eye and head during orientation) or sensory and motor systems (e.g., the visual and oculomotor systems) as well as more abstract functions such as attention and memory.