The inferior pulvinar and visual attention

描述(由申请人提供)：枕核与大部分视觉皮质紧密相连，导致许多人建议将这一神秘的大脑部分作为视觉角色。然而，人们对它在视觉处理中的作用知之甚少。在损伤、成像和记录研究的基础上，有人提出枕骨在引导视觉注意到特定空间区域的作用。在拟议的实验中，我们计划使用电微刺激和可逆失活来直接检验这一假说。我们将在有和没有扰动的情况下，测量纹外皮质的视觉检测性能和神经元反应。检测任务将是运动方向的改变，我们已经知道大脑皮层MT参与了这种知觉能力。这种设计允许进行两种截然不同的比较，每一种都对这一假设至关重要。首先，我们知道定向注意在纹状体外神经元的反应获得中产生行为益处和局部变化；枕区的激活应该模仿这种变化，而可逆的失活应该消除这种变化。此外，我们将能够得出结论，感知测量的影响是否可以通过支持视觉辨别的已知皮质回路来调节。

DESCRIPTION (provided by applicant): The pulvinar nucleus is richly interconnected with most of visual cortex, leading many to propose a visual role for this enigmatic part of the brain. However, little is known about its role in visual processing. On the basis of lesion, imaging, and recording studies, it has been proposed that pulvinar plays a role in directing visual attention to particular regions of space. In the proposed experiments, we plan to directly examine this hypothesis using electrical microstimulation and reversible inactivation. We will measure both visual detection performance and neuronal responses in extrastriate cortex, with and without perturbation. The detection task will be of a change in motion direction, and we already know that cortical area MT is involved in this kind of perceptual capability. The design allows two distinct comparisons to be made, each critical to this hypothesis. First, we know that directed attention produces behavioral benefits and local changes in the gain of response of extrastriate neurons; activation of pulvinar should mimic this change and reversible inactivation should eliminate it. Also, we will be able to conclude whether the effects measured perceptually could be mediated through known cortical circuits supporting visual discrimination.