Parietal mechanisms of vision and attention

描述(申请人提供)：顶叶皮质对于控制空间注意力至关重要。在人类中，单侧顶叶损伤会导致严重的对侧忽视--这种综合征的特征是未能注意到并定位到受损半球的对侧物体。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质在运动控制中的作用，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层机制知之甚少。我实验室研究的长期目标是确定独立于运动的视觉和注意力的顶层机制。拟议的实验将使用神经生理学实验，并结合清醒、行为正常的猴子的行为测试。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，将微量的药物注入被分析的区域，暂时使该区域安静下来，并测量这种短暂失活的行为影响。这些实验将使我们能够表征与视觉注意相关的神经活动，以及一组特定的神经元对引导注意力的重要性。我们将集中于猴子后顶叶皮质的一个细分，称为外侧顶内区。尽管有证据表明，这一区域对视力和注意力很重要，但它的具体贡献从未被研究过。这些实验旨在确定这一顶区对视觉的三个强烈依赖于注意的方面的影响：视野内孤立物体的检测(目标1)；拥挤视觉环境中单个物体的辨别(目标2)；以及基于自愿因素和身体突显(分别是内源和外源线索；目标3)的注意定向。这一结果有望极大地促进我们对注意力神经机制的理解，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.