NEUROBIOLOGY OF PREPARATORY SET IN MENTAL DISORDERS

描述(改编自申请者的摘要)：该项目将 继续对视觉注意的神经生物学进行研究 正常受试者和神经科患者。这些调查人员的前科 研究已经确定了与三个基本元素相关的神经区域 分配视觉注意力的操作：顶叶脱离， 中脑移动，丘脑吸引注意力。持续关注的焦点 这个项目的作用一直是中脑膝外膝状视觉 控制视觉引导行为的途径。计时器的量度 使用检测反应时间和扫视潜伏期来获得 从三个受试组收集关于胶合函数的证据： (A)在进行性核上性瘫痪患者中，丘脑的作用 检查损害的定向行为；(B)在偏盲患者中， 实验确定了哪些定向行为仅在 可用视觉输入来自视网膜顶盖通路；和(C)正常 人类受试者鼻侧和视网膜区视网膜顶盖投射的不对称性 我们利用颞侧视网膜来比较定位的效率。 注意力和眼球运动转移到颞侧和鼻侧。这些 研究证实，视网膜顶盖通路对 移动注意力和通过抑制在视觉扫描中有利于新颖性 重定向到最近出席的地点。 拟议的研究将进一步考察反身代词之间的相互作用 以及控制视觉注意力分配的神经过程。这个 目标是：(1)明确人类膝外途径在 将注意力定向到视觉信号；以及(2)确定这些信号如何 皮层下反射定向机制受高级中枢调节 它管理着自愿的、目标导向的行为。拟议中的实验 将检验中脑视觉通路具有特殊作用的假说 将注意力定向到外源信号和整合注意力 具有眼动控制功能。其他实验将调查 注意定向中的前额叶皮质和基底节 内生控制。这些研究将试图确定中脑是如何 反射定向的机制由这些较高的中枢调节，并且 无论是前额叶皮质还是基底节在 在延迟响应条件下定向，如果是，是否 涉及的机制反映了空间记忆能力，持续关注 眼球运动装置的位置或控制。

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.