The inferior pulvinar and visual attention

描述（由申请人提供）：枕核与大部分视觉皮层紧密相连，导致许多人提出大脑中这个神秘部分的视觉作用。然而，人们对其在视觉处理中的作用知之甚少。根据病变、成像和记录研究，已经提出枕状核在将视觉注意力引导到空间的特定区域中起作用。在提出的实验中，我们计划使用电微刺激和可逆失活直接检验这一假设。我们将测量视觉检测性能和皮层外皮层的神经元反应，有和没有扰动。检测任务将是运动方向的变化，我们已经知道皮层MT区域参与了这种感知能力。该设计允许进行两种不同的比较，每一种都对该假设至关重要。首先，我们知道定向注意会产生行为上的益处，也会引起外皮层神经元反应增益的局部变化；pulvinar的激活应该模仿这种变化，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层回路介导。

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.