Parietal mechanisms of vision and attention

描述（由申请人提供）：顶叶皮层对控制空间注意力至关重要。在人类中，单侧顶叶损伤可导致严重的对侧忽视——一种以无法注意和定位受损半球对侧物体为特征的综合征。忽视的困难表现为注意力缺陷，而不是感觉或运动缺陷。在非人类灵长类动物中，研究主要集中在顶叶皮层在控制运动中的作用，特别是眼睛、手臂或手的探索性运动。人们对注意力和视觉的顶叶机制知之甚少。我实验室的长期研究目标是确定独立于运动的视觉和注意力的顶叶机制。拟议中的实验将使用神经生理学实验，并结合对清醒、行为正常的猴子进行行为测试。在一些实验中，当猴子执行旨在测量注意力的心理物理任务时，神经活动被记录下来。在其他实验中，将微量药物注射到所分析的区域，使该区域暂时沉默，并测量这种短暂的失活对行为的影响。这些实验将使我们能够描述与视觉注意力相关的神经活动，以及一组特定神经元对指导注意力的重要性。我们将集中讨论猴子后顶叶皮层的一个细分区域，即外侧顶叶内区。虽然有证据表明这个区域对视觉和注意力很重要，但它的具体贡献从未被调查过。这些实验旨在确定顶叶区域对视觉的三个方面的影响，这些方面强烈依赖于注意力：视野内孤立物体的检测（目标1）；在拥挤的视觉环境中识别单个物体（目标2）；以及基于自愿因素和身体显著性的注意力定向（分别为内源性和外源性线索；目标3）。研究结果有望极大地促进我们对注意力的神经机制的理解，并使我们更接近于建立忽视的动物模型。

DESCRIPTION (provided by applicant): The parietal cortex is critically important for the control of spatial attention. In humans, unilateral damage to the parietal lobe can cause severe contralateral neglect - a syndrome characterized by failure to notice and orient toward objects contralateral to the lesioned hemisphere. The difficulties in neglect represent deficits of attention rather than sensory or motor deficits. In non-human primates, research has focused primarily on the role of the parietal cortex in the control of movement, in particular exploratory movements of the eye, arm or hand. Much less is known about the parietal mechanisms of attention and vision. The long-term goal of research in my laboratory is to determine the parietal mechanisms underlying vision and attention independently of movement. The proposed experiments will use neurophysiological experiments in conjunction with behavioral testing in awake, behaving monkeys. In some experiments neural activity is recorded while monkeys perform psychophysical tasks designed to measure attention. In other experiments, minute amounts of drugs are injected into the area analyzed, which temporarily silence this area, and the behavioral effects of such transient inactivation are measured. These experiments will allow us to characterize the neural activity associated with visual attention and the importance of a particular set of neurons for directing attention. We will concentrate on a subdivision of monkey posterior parietal cortex known as the lateral intraparietal area. Although evidence suggests that this area is important for vision and attention, its specific contributions have never been investigated. The experiments are designed to determine the impact of this parietal area on three aspects of vision that are strongly dependent on attention: the detection of isolated objects within the field of view (Aim 1); the discrimination of individual objects in crowded visual environments (Aim 2); and the orienting of attention based on voluntary factors and physical salience (endogenous and exogenous cues, respectively; Aim 3). The results are expected to significantly advance our understanding of the neural mechanisms of attention and to bring us closer toward establishing an animal model of neglect.