NEUROBIOLOGY OF PREPARATORY SET IN MENTAL DISORDERS

我们将研究预备组的神经生物学， 分离出认知成分和它们的神经基质， 这些大脑转换机制使人类能够做出反应， 灵活、高效地适应环境。 反应时间（RT） 实验将在正常人和神经系统中进行， 患者分离皮质和皮质下成分， 知觉和运动预备组。 任务类似于 那些已经在动物的单位记录中使用的 用于识别与以下相关的选择性增强的实验： 预备组，以便两个研究方向可以开始， 收敛。 知觉集任务涉及一个简单的RT手册 在检测到视野中的亮度变化时的响应; 运动组任务涉及选择RT手动运动。 为 任务，预备集是由一个初步的视觉线索， 指示受试者在哪里期待目标或 运动准备。 预备集是推断，其时间 根据RT中的促进或抑制来测量过程 性能取决于球杆是否正确准备 为后续的目标。 我们将测量转换 进行性核上性麻痹患者的定向，以及 正常人颞侧和鼻侧半野定向的比较 受试者，以测试假设，中脑中心是 既涉及将注意力转移到外源信号， 协调注意力和眼球运动。 实验 额叶和尾状核病变的患者将检验这一假设 这些结构参与了将注意力转移到 内源控制 丘脑性痴呆患者的实验 病变将检验枕参与 在一个新的位置吸引注意力。 患者实验 帕金森氏病患者的额叶和小脑病变 研究皮质和皮质下中心在 调节运动机能 虽然这一点的主要重要性 研究在于它有可能阐明一个基本的 神经生物学的问题，它也有潜在的临床意义， 好. 它可能会导致更合理的方法， 注意力和运动计划的患者康复 由于神经系统疾病引起的疾病。

We will investigate the neurobiology of preparatory set in order to isolate the cognitive components, and their neural substrates, of those brain switching mechanisms which enable humans to respond flexibly and efficiently to their environment. Reaction time (RT) experiments will be conducted in normal humans and neurological patients to separate the cortical and subcortical components of perceptual and motor preparatory set. The tasks are similar to those which have been employed in unit recordings in animal experiments for identifying selective enhancement related to preparatory set, so that the two strands of research may begin to converge. The perceptual set tasks involve a simple RT manual response on detecting a luminance changes in the visual field; the motor set tasks involve choice RT manual movements. For both tasks, preparatory set is induced by a preliminary visual cue which instructs the subject where to expect the target or which movement to prepare. Preparatory set is inferred, and its time course measured, on the basis of facilitation or inhibition in RT performance depending upon whether the cue correctly prepares the subject for the subsequent target. We will measure convert orienting in patients with progressive supranuclear palsy, and compare orienting into temporal and nasal hemifields in normal subjects, to test the hypotheses that midbrain centers are involved both in moving attention to exogenous signals, and in coordinating attention with eye movements. Experiments in patients with frontal and caudate lesions will test the hypothesis that these structures are involved in moving attention under endogenous control. Experiments in patients with thalamic lesions will test the hypothesis that the pulvinar is involved in engaging attention at a new location. Experiments in patients with Parkinson's disease, frontal lobe and cerebellar lesions will investigate the role of cortical and subcortical centers in mediating motor set. While the primary importance of this research lies in its potential for elucidating a fundamental problem in neurobiology, it also has potential clinical relevance as well. It may lead to more rational approaches to the rehabilitation of patients with attention and motor planning disorders due to neurological diseases.