Neural mechanisms mediating visual search

介导视觉搜索的神经机制

• 批准号: 8895327
• 负责人: Robert Desimone
• 金额: $ 36.92万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-08-01 至 2016-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8895327
• 关键词: Accounting; Area; Attention; Behavior; Behavioral; Biological; Blindness; Brain; Cell Nucleus; Cells; Child; Color; Complex; Crowding; Data; Dependence; Development; Disease; Etiology; Eye Movements; Feedback; Food; Health; Inferior; Laboratories; Lateral; Location; Maps; Measures; Mediating; Memory; Methods; Nervous system structure; Neurons; Performance; Play; Population; Positioning Attribute; Prefrontal Cortex; Primates; Process; Property; Pulvinar structure; Retina; Role; Shapes; Short-Term Memory; Signal Transduction; Source; Stimulus; Structure; System; Task Performances; Techniques; Temporal Lobe; Testing; Thalamic structure; Time; V4 neuron; Visual; Visual Cortex; Work; area V4; base; design; directed attention; extrastriate visual cortex; frontal eye fields; information processing; insight; neural circuit; neural prosthesis; neuromechanism; neurophysiology; neuroregulation; operation; optogenetics; relating to nervous system; response; visual imagery; visual information; visual process; visual processing; visual search

DESCRIPTION (provided by applicant): We must often search cluttered scenes for items of immediate behavioral relevance - e.g. our food, our car keys, our child, and so on. In each case, we use our memory of the object's features to effectively guide our search, so that we are not forced to inspect every object in a crowded scene individually. Efficient visual search is critical for efficient visually guided behavior. Although much is known about the biological mechanisms that underlie the ability to attend to locations, very little is known about the mechanisms underlying visual search guided by object features. We do not yet understand where the information about the relevant object features is stored in the nervous system, how that information is used to guide eye movements to inspect object that are good candidates for the searched-for item, or how the feature information modulates the information processed in our visual cortex. To design an effective neural prosthesis or to treat people with attentional disorders, we need a better understanding of feature attention in visual search at the systems level. A better understanding of feature attention will likely also give us insight into the mechanisms underlying visual working memory and visual imagery, as these related functions seem to involve at least partially overlapping neural circuits. Two key structures that may play a role in the guidance of feature attention during visual search are the prefrontal cortex and the pulvinar nucleus of the thalamus. In fact, the pulvinar may serve to relay critical feature information from prefrontal cortex to visual cortex. Our Aims are focused on these two structures, and we are guided by our preliminary data regarding their functions. In Aim 1, we will simultaneously record from neurons in Area 45 of the prefrontal cortex, the frontal eye fields (FEF) and area V4 of visual cortex during performance of a visual search task. These recordings will test hypotheses about how prefrontal cells influence the subsequent processing of object feature information in FEF and area V4. In Aim 2, we will use newly developed optogenetic techniques during performance of the same tests of feature attention used in Aim 1, to test causal hypotheses about how the prefrontal cortex influences both behavior during search and the responses of FEF and V4 neurons. The optogenetic techniques we have successfully implemented with our collaborators will allow us to suppress neural circuits at precise locations and for precise periods of time. In Aim 3, we will record simultaneously from the pulvinar, area V4, and the inferior temporal cortex during the same tests of feature attention. We will test hypotheses about how the pulvinar regulates cortical processing during feature attention, including its role in synchronizing and de-synchronizing activity in cortical population. We will then test our conclusions using the same optogenetic techniques used in Aim 2, to suppress pulvinar activity at critical times during the performance of the tasks. In total, we expect these studies to give us the best account so far of how the interactions among multiple brain structures leads to effective visual processing during attention to object features.

描述(由申请者提供)：我们必须经常在杂乱的场景中寻找与行为直接相关的物品--例如我们的食物、车钥匙、孩子等等。在每一种情况下，我们都会利用对物体特征的记忆来有效地指导我们的搜索，这样我们就不会被迫在拥挤的场景中单独检查每一个物体。高效的视觉搜索至关重要 以实现高效的视觉引导行为。虽然人们对注意位置能力的生物学机制了解很多，但对物体特征引导的视觉搜索的机制知之甚少。我们还不知道关于相关物体特征的信息在神经系统中存储在哪里，这些信息如何被用来指导眼球运动来检查哪些物体是搜索项目的良好候选者，或者特征信息如何调节我们视觉皮质中处理的信息。为了设计有效的神经假体或治疗注意障碍患者，我们需要在系统水平上更好地理解视觉搜索中的特征注意。更好地理解特征注意可能也会让我们深入了解视觉工作记忆和视觉意象的潜在机制，因为这些相关功能似乎至少涉及部分重叠的神经回路。在视觉搜索过程中，两个可能在特征注意引导中发挥作用的关键结构是丘脑的前额叶皮质和枕核。事实上，枕骨可能起到将关键特征信息从前额叶皮质传递到视觉皮质的作用。我们的目标集中在这两个结构上，我们以关于它们功能的初步数据为指导。在目标1中，我们将在执行视觉搜索任务的过程中，同时记录前额叶皮质45区的神经元、视觉皮质的额叶眼场(FEF)和V4区。这些记录将测试关于前额叶细胞如何影响FEF和V4区中物体特征信息的后续处理的假设。在目标2中，我们将在执行目标1中使用的相同特征注意测试时使用新开发的光遗传学技术，以测试关于前额叶皮质如何影响搜索行为以及FEF和V4神经元反应的因果假设。我们与合作伙伴成功实施的光遗传技术将使我们能够在精确的位置和精确的时间段抑制神经回路。在目标3中，我们将在相同的特征注意测试中，同时从枕部、V4区和颞叶下部皮质进行记录。 我们将测试有关枕骨在特征注意过程中如何调节皮质加工的假说，包括它在大脑皮层群体中同步和去同步活动中的作用。然后，我们将使用在目标2中使用的相同的光遗传学技术来测试我们的结论，以在任务执行期间的关键时间抑制枕骨活动。总而言之，我们希望这些研究能为我们提供到目前为止最好的解释，说明多个大脑结构之间的相互作用如何在注意物体特征的过程中导致有效的视觉处理。