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，因为它在视觉感知中的重要性。行为范式，如变化盲视，向我们表明，当我们认为我们感知了整个视觉世界时，我们只带走了我们所关注的区域或物体的信息。因为视觉注意是视觉感知的基础，它是我们与感知世界的大多数互动的基础——包括我们的身体互动和更多的智力互动，比如学习和记忆。因此，增加我们对注意力引导机制的理解是至关重要的，这使我们能够更深入地了解大脑如何根据外部和认知输入做出决定，并从长远来看，洞察视觉感知本身的机制。在这项研究中，我们测试了侧顶叶内区（LIP）作为优先地图的假设-视觉世界的地图，用于指导注意力的分配。该理论认为，注意力被分配到地图上活动最多的位置。我们假设这张地图被用来引导外围（隐蔽）注意力和眼球运动（公开注意力）。在目标1中，我们将通过比较隐蔽注意力分散、集中或偏向特定位置的情况下LIP和视觉区域V4的活动来检验这一假设。我们预测V4的活动将以一种与LIP活动的空间分布直接相关的方式被调节- LIP活动的峰值将在V4中产生强烈的注意调制。我们将通过刺激LIP并显示V4活动中可预测的调制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了，它就会在地图上被抑制，这样凝视的焦点(即。（显性注意力）不只是在地图上的两个最高点之间反弹。我们将通过检查LIP在相同刺激下的活动来验证这一点，这些刺激是在以前看过或没有看过的情况下进行的。我们预计，在已经看到刺激措施的情况下，反应将明显较低。然后，我们将通过在任务中刺激LIP来测试这种活动的减少是否对行为很重要。我们预计，这将导致更多的眼球运动发生在视觉刺激的刺激位置，而不是同一刺激物在试验中没有发生刺激。这些实验旨在了解LIP在注意力分配中所起的作用，结果可能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缺陷障碍患者中所见的缺陷，对这一机制的更深入了解可能有助于开发对抗这些问题的药理学或行为学方法。

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.