Neural Correlates of spatial and object-based selection

描述（由申请人提供）：大脑无法充分审查每时每刻存在的丰富信息，因此选择过程不断对环境进行采样。通过确定环境的哪些方面接受优先处理，这个选择过程无疑对几乎所有的大脑功能都有巨大的影响。因此，理解共同决定选择的神经机制，广泛地称为选择性注意，一直是视觉神经科学的最大挑战之一。选择性注意通常由行为目标和刺激显著性的组合来引导。例如，大脑有限的处理资源可以被部署在特定的位置，要么是在预期一些重要的事情，要么是在响应一个特别强烈或突然的刺激。但选择性注意是一个动态的、持续的过程，而对特定位置的偏好只是这个过程中的一步。在部署注意聚光灯之后，存在基于局部对象属性继续的后续注意调制级联。对人类的研究表明，在提示位置的增强处理在物体的视觉边界内传播，即使物体的一部分延伸到任务相关位置之外。这种刺激驱动的选择性注意机制，可以被解释为空间选择的细化，被称为“基于对象的空间选择”。然而，在这个持续的过程中， 选择过程，空间选择，已经被很好地表征，基于对象的空间选择的神经相关性是未知的。因此，本提案的第一个目标是通过表征归因于刺激驱动的、基于对象的空间选择的猴子纹外神经元中的注意力调制，然后将其与归因于目标导向的空间选择的注意力调制进行比较（在相同的实验任务内）来弥合这一差距。本建议的第二个目标是确定在何种程度上的注意力调制在纹外神经元驱动的其他脑区已知的结构，介导的注意力选择的网络的一部分，并确定是否interareal相互作用取决于注意力选择的机制。中心假设是，空间选择和基于对象的空间选择介导的可分离的神经过程，相互作用，以解析和过滤的视觉环境。我们将探索这些目标和我们的中心假设，同时记录从V4区，枕，和额叶眼场（FEF）在猴子训练上执行的注意力任务，同时进入目标导向的空间选择和刺激驱动的，基于对象的空间选择。多位点记录技术将利用fMRI和DTI引导的电极放置来定义匹配的网络节点。注意力障碍对人类健康具有严重后果（例如，脑卒中后空间忽视，ADHD）。改善这些疾病的治疗方法的第一步，以及这项建议的目标，是更好地理解选择性注意的神经机制。

DESCRIPTION (provided by applicant): The brain cannot fully scrutinize the wealth of information that is present at each moment, and so a selection process continually samples the environment. By determining which aspects of the environment receive preferred processing, this selection process undoubtedly has a huge influence on nearly all brain functions. An understanding of the neural mechanisms that collectively determine selection, broadly referred to as selective attention, has therefore been one of the great challenges of visual neuroscience. Selective attention is often guided by a combination of behavioral goals and stimulus salience. For example, the brain's limited processing resources can be deployed at a specific location either in anticipation of something important, or in response to a particularly strong or sudden stimulus. But selective attention is a dynamic and ongoing process, and introducing a bias toward a particular location is just one step in this process. Following deployment of the attentional spotlight, there is a subsequent cascade of attentional modulation that continues based on local object properties. Studies in humans have shown that enhanced processing at a cued location spreads within an object's visual boundaries, even when part of the object extends outside the task-relevant location. This stimulus-driven mechanism of selective attention, which can be construed as a refinement of spatial selection, has been referred to as "object-based spatial selection". Whereas the neural correlates of the first step in this continual selection process, spatial selection, have been well-characterized, the neural correlates of object- based spatial selection are unknown. The first objective of the present proposal is therefore to bridge this gap by characterizing attentional modulation in monkey extrastriate neurons attributable to stimulus-driven, object- based spatial selection, and then comparing it to attentional modulation attributable to goal-oriented spatial selection (within the same experimental task). A second objective of the present proposal is to determine the extent to which attentional modulation in extrastriate neurons is driven by other brain regions known to be part of the network of structures that mediate attentional selection, and to determine whether such interareal interactions vary depending on the mechanism of attentional selection. The central hypothesis is that spatial selection and object-based spatial selection are mediated through separable neural processes that interact to parse and filter the visual environment. We will probe these objectives and our central hypothesis by recording simultaneously from area V4, the pulvinar, and the frontal eye field (FEF) in monkeys trained on performing an attention task that simultaneously taps into goal-oriented spatial selection and stimulus-driven, object-based spatial selection. The multi-site recording technique will utilize fMRI- and DTI-guided electrode placement to define matching network nodes. Attentional disorders have severe consequences for human health (e.g., spatial neglect after stroke, ADHD). A necessary first step toward improving treatment of these disorders, and the goal of this proposal, is to gain a better understanding of the neural mechanisms of selective attention.