The Neural Mechanisms Underlying the Guidance of Visual Attention

描述（由申请人提供）：我们研究视觉注意力，因为它在视觉感知中的重要性。行为范式，如变化盲视，已经向我们表明，虽然我们认为我们感知到了整个视觉世界，但我们只带走了我们所关注的区域或物体的信息。因为视觉注意力是视觉感知的基础，它是我们与感知世界的大部分互动的基础--包括我们的身体互动和更多的智力互动，如学习和记忆。因此，增加我们对注意力引导机制的理解至关重要，这有助于我们更深入地了解大脑如何根据外部和认知输入做出决策，并从长远来看，深入了解视觉感知本身的机制。在这项研究中，我们测试的假设，外侧顶内区（LIP）作为优先地图-地图的视觉世界，用于指导分配的注意力。该理论认为，注意力被分配到地图上活动最多的位置。我们假设，这张地图是用来指导周边（隐蔽）注意和眼球运动（显性注意）。在目标1中，我们将通过比较LIP和视觉V4区的活动来验证这一假设，在这种条件下，内隐注意力被分散，集中或偏向于特定位置。我们预测，活动在V4将调制的方式，是直接相关的空间分布的活动在LIP -一个高峰的活动在LIP将产生强烈的注意力调制在V4。我们将通过刺激LIP并显示V4活性的可预测调节来进一步测试这一点。在目标2中，我们将测试我们的系统模型所做的预测，即一旦一个物体被看过，它就会被抑制在地图上，这样凝视的焦点（即。不只是在地图上的两个最高点之间跳动。我们将通过检查LIP在相同刺激下的活动来测试这一点，在这种情况下，它已经或尚未被研究过。我们预计，在已经看到刺激措施的情况下，反应将明显降低。然后，我们将通过在任务期间刺激LIP来测试活动的减少是否对行为重要。我们预计，这将导致更多的眼球运动被作出的视觉刺激在刺激的位置比相同的刺激在试验中，刺激不发生。这些实验旨在了解LIP在注意力分配中的作用，其结果可用于微调我们的注意力分配模型。这项研究的结果帮助我们了解大脑决定什么值得关注的方式。鉴于视觉注意力在日常生活中的重要性，以及在顶叶病变或注意力缺陷障碍患者中观察到的缺陷，对这种机制的更好理解可能有助于开发药物或行为方法来解决这些问题。

Description (provided by applicant): We study visual attention because of its importance in visual perception. Behavioral paradigms, such as change blindness, have shown us that while we think we perceive the whole visual world, we only take away information about regions or objects that we have attended. Because visual attention is a foundation of visual perception, it underlies most of our interactions with the perceived world - both our physical interactions and more intellectual interactions, such as learning and memory. Thus, increasing our understanding of the mechanisms underlying the guidance of attention is critical in allowing us to gain a deeper insight into how the brain makes decisions based on both external and cognitive inputs and, in the long run, insight into the mechanisms underlying visual perception itself. In this study, we test the hypothesis that the lateral intraparietal area (LIP) acts as a priority map - a map of the visual world that is used to guide the allocation of attention. The theory is that attention is allocated to the location on the map with the greatest activity. We have hypothesized that this map is used to guide both peripheral (covert) attention and eye movements (overt attention). In aim 1, we will test this hypothesis by comparing the activity in LIP and visual area V4 under conditions in which covert attention is spread, focused or biased to a particular location. We predict that activity in V4 will be modulated in a way that is directly related to the spatial distribution of activity in LIP - a peak of activity in LIP will produce strong attentional modulation in V4. We will further test this by stimulating LIP and showing predictable modulation in V4 activity. In aim 2, we will test a prediction made by our model of the system, namely that once an object has been looked at, it is suppressed on the map so that the focus of gaze (ie. overt attention) doesn't just bounce between the two highest points on the map. We will test this by examining the activity in LIP to an identical stimulus under conditions in which it has or has not been looked at previously. We expect that the response will be significantly lower in the case in which the stimulus has already been seen. We will then test whether this reduction in activity is important to the behavior by stimulating LIP during the task. We expect that this will result in more eye movements being made to the visual stimulus at the stimulated location than to the same stimulus in trials in which stimulation does not occur. These experiments are aimed at understanding the role that LIP plays in the allocation of attention and the results may be used to fine-tune our model of how attention is allocated. PUBLIC HEALTH RELEVANCE The results from this study help us understand the way the brain decides what is worth paying attention to. Given the importance of visual attention in everyday life and the deficits seen in patients with parietal lesions or attention deficit disorders, a greater understanding of this mechanism may aid in the development of pharmacological or behavioral methods to combat these problems.