ATTENTION SHIFTING HYPOTHESIS FOR THE BASAL GANGLIA

该项目将确定基底神经节在选择性脑损伤中的作用。 关注，是出于对新兴市场的考虑 对额纹状体环路的理解。尽管帕金森病患者 有运动问题，神经解剖学的考虑表明 对由基底节形成的计算的一般描述。一 神经回路始于背外侧前额叶皮质，该区域通常 被认为是为不同的颜色领域提供工作记忆的补充， 形式和空间。该环路穿过基底神经节。 与来自汽车前额区的赛道相同的方式， 这表明基底节对每个 巡回赛。我们提出了一种注意计算，其中基本的 神经节参与建立、维护和交换SET。 对这一理论的决定性考验将来自于 帕金森患者和额叶中风患者在 建立和交换涉及颜色和形式的集合。 我们实验室和其他机构以前对帕金森患者的研究 没有提供证据证明基底节在移位中的作用 空间注意力，或运动序列之间的转移。因此，我们 区分注意力和选择性的偏向功能 功能，并表明早期研究未能确定 基底节的注意功能是由于他们使用了偏向 范例。这些范例提示一个刺激特征或维度， 如果意外发生，则将其他内容留作相关。 另一方面，选择要求不相关的维度 主动阻止以防止其激活给定的响应 任务上下文。由于基底节同时含有抑制性和网状结构 激励子电路，这种双重特性符合我们的建议 基底节既涉及相关维度的选择，也涉及 抑制不相关的因素。基底节注意学说 帕金森病患者将测试额叶-纹状体回路内的转换 患者通过对药物状态的操纵，以及在有 前额叶背外侧皮质梗塞的一系列实验 注意颜色和形式。

This project will define the role of the basal ganglia in selective attention, and is motivated by a consideration of an emerging understanding of fronto-striatal circuits. Although Parkinson patients have motor problems, consideration of neuroanatomy suggests a more general description of the computation formed by the basal ganglia. One neural circuit begins in dorsolateral prefrontal cortex, an area often thought to subserve working memory for the separate domains of color, form, and space. The circuit courses through the basal ganglia in a manner not unlike that for circuits coming from motoric frontal regions, suggesting that the basal ganglia performs the same computation for each circuit. We propose an attentional computation in which the basal ganglia are involved in establishing, maintaining, and switching set. A decisive test of the theory would come from a demonstration that Parkinson patients and frontal stroke patients have impairment in establishing and switching sets involving color and form. Previous studies of Parkinson patients in our laboratories and others have not provided evidence for a role of the basal ganglia in shifting spatial attention, or shifting between movement sequences. We therefore draw a distinction between biasing functions of attention and selective functions, and suggest that the failure of earlier studies to identify attentional functions for basal ganglia was due to their use of biasing paradigms. These paradigms cue for one stimulus feature or dimension, leaving others as still relevant should they unexpectedly occur. Selection, on the other hand, requires that irrelevant dimensions be actively blocked to prevent their activation of a response in a given task context. Since the basal ganglia contain both inhibitory and net excitatory subcircuits, this dual characteristic fits with our proposal that the basal ganglia involves both selection of relevant dimensions and inhibition of irrelevant ones. The theory of basal ganglia attention switching within fronto-striatal circuits will be tested in Parkinson patients by manipulations of medication state, and in patients with infarcts of dorsolateral prefrontal cortex in a series of experiments on attention to color and form.