The role of the pulvinar in visual attention

枕丘在视觉注意力中的作用

• 批准号: 6907656
• 负责人: KENNETH H BRITTEN
• 金额: $ 15.06万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-04-01 至 2008-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6907656
• 关键词: Macaca mulatta; action potentials; attention; behavioral /social science research tag; brain electrical activity; brain mapping; cues; electrodes; electrostimulus; neural information processing; neural transmission; neuropsychology; pulvinar thalami; temporal lobe /cortex; visual cortex; visual feedback; visual perception

DESCRIPTION (provided by applicant): The pulvinar nucleus of the thalamus is one of the most enigmatic structures in the brain. Of thalamic nuclei, it shows the largest increase in size with evolution, keeping pace with the size of primate neocortex. Despite considerable effort, its function remains essentially completely unknown. Two related suggestions dominate current thinking about the pulvinar, and each has some experimental support. Neither, however, has been critically tested, and the present application is intended to provide this critical test of both ideas. The first idea is that the pulvinar controls the spatial location of directed attention. This idea has support - though not conclusive - from lesion studies and physiological recording studies. We plan to directly test this idea by perturbing activity in the pulvinar while recording in extrastriate cortex. We know that directed attention produces local changes in the gain of response of extrastriate neurons; activation of the pulvinar should mimic this change and reversible inactivation of the pulvinar should eliminate it. The other suggestion for the role of the pulvinar concerns the mechanism of such gain changes in sensory cortex. In particular, it has been suggested that recurrent projections between the pulvinar and cortical structures control the flow of information between cortical areas; this regulation might underlie any role in directing spatial attention. We plan to test this idea using multiple electrode recording in extrastriate cortex. Two dorsal extrastriate areas, the middle temporal (MT) and the medial superior temporal (MST) are both connected to the same subdivision of the pulvinar (Plm), and also connected with each other - MT provides a dominant source of feedforward input to MST. We will record from both structures simultaneously while again perturbing the activity in the pulvinar. If the connections with the pulvinar regulate information flow in visual cortex, we predict that such perturbation will modulate the cross-correlation of activity between MT and MST. Success on either aim will dramatically influence our thinking about the function of thalamocortical circuits.

描述（由申请人提供）：丘脑的枕核是大脑中最神秘的结构之一。在丘脑核中，随着进化，它的尺寸增加幅度最大，与灵长类新皮质的尺寸保持同步。尽管付出了巨大的努力，但它的功能基本上仍然完全未知。两个相关的建议主导了当前关于 pulvinar 的思考，并且每个建议都有一些实验支持。然而，这两种想法都没有经过严格的测试，并且本申请旨在提供对这两种想法的这种严格测试。第一个想法是枕丘控制定向注意力的空间位置。这个想法得到了病变研究和生理记录研究的支持（尽管不是决定性的）。我们计划通过在纹状外皮层中记录时干扰枕丘的活动来直接测试这个想法。我们知道，定向注意力会导致纹状神经元反应增益的局部变化。丘脑的激活应该模仿这种变化，而丘脑的可逆失活应该消除这种变化。关于枕丘作用的另一个建议涉及感觉皮层中这种增益变化的机制。特别是，有人认为枕丘和皮质结构之间的循环投射控制着皮质区域之间的信息流。这种调节可能是引导空间注意力的任何作用的基础。我们计划使用纹外皮质中的多个电极记录来测试这个想法。两个背侧纹外区域，即中颞叶 (MT) 和内侧上颞叶 (MST) 均连接至枕丘 (Plm) 的同一分区，并且也相互连接 - MT 为 MST 提供前馈输入的主要来源。我们将同时从这两个结构进行记录，同时再次扰乱丘陵的活动。如果与枕丘的连接调节视觉皮层的信息流，我们预测这种扰动将调节 MT 和 MST 之间活动的互相关性。这两个目标的成功都会极大地影响我们对丘脑皮质回路功能的思考。