Diencephalic Mechanisms of Visuomotor Integration

描述（由申请人提供）：在一个典型的视觉场景中，关于在哪里看的决定是由个体刺激和当前行为目标的相对显著性决定的。迄今为止，大多数关于视觉定向的认知控制的研究都是针对额叶皮质的。然而，越来越多的证据表明，与工作记忆和决策相关的信号严重依赖于额叶皮层和皮层下结构（如基底神经节、小脑和丘脑）之间的相互作用。丘脑在这些皮层下结构中是独特的；除了向皮层提供直接输入外，其组成核还介导基底神经节和小脑对各自皮层目标的影响。尽管它的解剖位置至关重要，但实际上对丘脑中央所代表的信息的性质一无所知。目前的实验试图充分表征与产生视觉引导的跳眼运动相关的认知因素的中央丘脑表征。提出的研究将首次检查丘脑中央核的潜在重要性，以及它们介导的皮层下-皮层相互作用，对目标导向的跳眼运动的认知控制。这样，这些实验将有助于定义视觉运动认知的基本神经基质。

DESCRIPTION (provided by applicant): Decisions about where to look within a typical visual scene are governed by the relative salience of individual stimuli and current behavioral objectives. To date, the majority of studies examining the cognitive control of visual orienting have targeted frontal cortex. However, there is growing evidence to suggest that signals related to working memory and decision-making are critically dependent on interactions between frontal cortex and subcortical structures such as the basal ganglia, cerebellum, and thalamus. Thalamus is unique among these subcortical structures; in addition to providing direct input to cortex, its constituent nuclei mediate the influences of both the basal ganglia and cerebellum on their respective cortical targets. Despite its critical anatomical position, virtually nothing is known about the nature of the information represented in central thalamus. The current experiments seek to fully characterize the central thalamic representations of cognitive factors relevant for producing visually-guided saccadic eye movements. The proposed studies will be the first to examine the potential importance of central thalamic nuclei, and the subcortical-cortical interactions they mediate, to the cognitive control of goal-directed saccadic eye movements. In doing so, these experiments will help to define the essential neural substrates for visuomotor cognition.