Interaction of Visual and Oculomotor Signals in Cortex

视觉空间注意是一种重要的心理操作，它允许我们在面对过多的视觉输入时选择性地只处理相关信息。理解这种现象的潜在神经机制是我们理解认知的神经基础的核心，也是改善人类患者注意力障碍的希望的核心。我们和其他最近的工作表明，更好地了解视觉和眼动机制之间的相互作用可能是建立空间注意的因果神经基础的关键。因此，这项提案的长期目标是了解灵长类动物大脑中眼和视觉机制之间的相互作用。这一目标将通过以下三个目标来实现：我们的第一个目标是测试的因果关系的额叶皮层眼跳机制中的directinq隐蔽的空间注意和驾驶选择在视觉皮层。额叶眼野（FEF）内的神经元活动将被灭活，我们将检查这对猴子主动将注意力隐蔽地引导到受影响的空间部分的能力的影响，以及广泛观察到的纹外区V4中的注意力神经相关性被消除的程度。我们的第二个目的是比较FEF微刺激期间在纹外皮层观察到的视觉Qain的变化与已知的内隐空间注意的影响。我们将研究如何在V4反应的变化所造成的阈下FEF微刺激在被动固定的猴子平行的动物训练，以直接内隐注意自愿观察到的调制。我们的第三个目标是检查之间的关系的概率，眼跳将作出视觉刺激和增益的视觉皮层反应的刺激。我们将通过系统地改变FEF微刺激的参数来直接操纵扫视概率，并研究 这种对V4区视觉反应增益的操纵。这项研究可能会深入了解人类注意力障碍的生理基础，这影响了美国5%的儿童，也可能会深入了解视觉障碍的问题。 协调，如阅读障碍，这影响了大约10%的美国公民。

Visual spatial attention is a critical mental operation that allows us to selectively process only relevant information in the face of an overabundance of visual input. Understanding the underlying neural mechanisms of this phenomenon is central to our understanding of the neural basis of cognition and central to any hope of ameliorating disorders of attention in human patients. Ours and other recent work suggests that better knowledge of the interplay between visual and oculomotor mechanisms may be the key to establishing a causal neural basis of spatial attention. Thus, the long-term goal of this proposal is to understand the reciprocal interactions between oculomotor and vision mechanisms in the primate brain. This goal will be pursued via the following three aims: Our first aim is to test the causal role of frontal cortical saccade mechanisms in directinq covert spatial attention and in drivinq selection in visual cortex. Neuronal activity within the frontal eye field (FEF) will be inactivated pharmacologically and we will examine the effect of this on the ability of monkeys to voluntarily direct attention covertly to the affected part of space, and on the degree to which the widely observed neural correlates of attention in extrastriate area V4 are eliminated. Our second aim is to compare the changes in visual qain observed in extrastriate cortex during FEF microstimulation with the known effects of covert spatial attention. We will examine how the changes in V4 responses caused by subthreshold FEF microstimulation in passively fixating monkeys parallel the modulations observed in animals trained to direct covert attention voluntarily. Our third aim is to examine the relationship between the probability that a saccade will be made to a visual stimulus and the gain of visual cortical responses to that stimulus. We will directly manipulate saccade probability by systematically varying the parameters of FEF microstimulation and study the effect of this manipulation on the gain of visual responses in area V4. This research may provide insight into the physiological basis of disorders of attention in humans, which affect up to 5% of children in the U.S, and may also provide insight into problems of visual-oculomotor coordination, such as dyslexia, which affects approximately 10% of U.S. citizens.