NEUROBIOLOGY OF PREPARATORY SET IN MENTAL DISORDERS

描述（根据申请人摘要改编）：该项目将 继续进行视觉注意力的神经生物学研究， 正常受试者和神经病患者。 这些调查人员之前 这项工作已经确定了与三个基本神经元相关的神经区域， 分配视觉注意力的操作：顶叶脱离， 中脑活动，丘脑引起注意。 继续重点 中脑外膝状体视觉的作用 控制视觉引导行为的途径。 天文台的计时措施 检测反应时和眼跳潜伏期，以获得 来自三个受试者群体的关于丘功能的汇聚证据： (a)在进行性核上性麻痹患者中， 检查定向行为的损伤;（B）在偏盲患者中， 实验确定当唯一的定向行为被保留时， 可用的视觉输入来自视网膜顶盖通路;以及（c）在正常的 在人类受试者中，鼻和 颞侧半视网膜被用来比较定向的效率 注意力和眼球运动进入颞侧和鼻侧半野。 这些 研究已经确定视网膜顶盖通路对于 移动注意力和通过抑制视觉扫描中的新奇来促进视觉扫描 重新定位到最近去过的地方 建议的研究将进一步研究反身性与 和控制视觉注意力分配的神经过程。 的 目的是：（1）明确人类膝状体外通路在 注意力集中于视觉信号;（2）确定这些 皮层下反射定向机制由高级中枢调节 控制着自愿的目标导向的行为 拟议的实验 将检验中脑视觉通路在大脑中的特殊作用 在将注意力导向外源信号和整合注意力方面， 眼动控制。 其他实验将研究 前额叶皮层和基底神经节在定向注意下 内源控制 这些研究试图确定中脑 反射定向的机制由这些高级中心调节， 前额叶皮层或基底神经节是否在 在延迟响应条件下进行定向，如果是， 涉及的机制反映了空间记忆能力，持续的注意力， 一个位置，或控制视力设置。

DESCRIPTION (ADAPTED FROM THE APPLICANT'S ABSTRACT): This project would continue ongoing investigations of the neurobiology of visual attention in normal subjects and neurologic patients. These investigators' previous work has identified the neural regions associated with three elementary operations for allocating visual attention: the parietal lobe disengages, the midbrain moves, and the thalamus engages attention. A continuing focus of this project has been the role of midbrain extra-geniculate visual pathways in controlling visually guided behavior. Chronometric measures of detection reaction time and saccade latency are employed to obtain converging evidence about collicular function from three subject groups: (a) in progressive supranuclear palsy patients, the effects of collicular lesions are examined on orienting behavior; (b) in hemianopic patients, experiments determine what orienting behaviors are preserved when the only available visual input is from the retinotectal pathway; and (c) in normal human subjects, an asymmetry in retinotectal projections from nasal and temporal hemiretinae is exploited to compare the efficiency of orienting attention and eye movements into temporal and nasal hemifields. These studies have established that the retinotectal pathway is critical for moving attention and for favoring novelty in visual scanning by inhibiting reorienting to recently attended locations. The studies proposed would further examine the interplay between reflexive and controlled neural processes in the allocation of visual attention. The goals are: (1) to specify the role of human extra-geniculate pathways in orienting attention to visual signals; and (2) to determine how these subcortical mechanisms for reflex orienting are regulated by higher centers which govern voluntary, goal-directed behavior. The proposed experiments would test the hypothesis that midbrain visual pathways have a special role in orienting attention to exogenous signals and in integrating attention with eye movement control. Other experiments would investigate the role of prefrontal cortex and the basal ganglia in orienting attention under endogenous control. These studies would attempt to determine how midbrain mechanisms for reflex orienting are regulated by these higher centers, and whether the prefrontal cortex or basal ganglia have a special role in orienting under delayed response conditions and, if so, whether the mechanisms involved reflect spatial memory capacity, sustained attention to a location, or control of oculomotor set.