The role of area V4 in the perception and recognition of visual objects

V4区在视觉物体感知和识别中的作用

• 批准号: 10597040
• 负责人: Anitha Pasupathy
• 金额: $ 54.08万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-04-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10597040
• 关键词: Address; Affect; Age related macular degeneration; Agnosia; Animal Behavior; Animals; Area; Attention; Behavior; Behavior Control; Behavior assessment; Behavioral; Behavioral Paradigm; Brain Diseases; Brain region; Child; Clutterings; Communication; Communication impairment; Computer Models; Crowding; Data; Diagnosis; Discrimination; Disease; Electrodes; Environment; Exhibits; Feedback; Functional disorder; Human; Image; Impairment; Individual; Methods; Modeling; Monkeys; Neurons; Pathway interactions; Patients; Perception; Performance; Population; Prefrontal Cortex; Primates; Process; Psychophysics; Resolution; Role; Sensory; Shapes; Stimulus; Structure; Symptoms; Texture; Time; Titrations; V2 neuron; V4 neuron; Vision; Visual; Visual Cortex; Visual Pathways; Visual System; Work; area V4; attentional control; autism spectrum disorder; awake; behavior influence; design; experimental study; extrastriate visual cortex; fovea centralis; frontal lobe; human subject; inattentional blindness; insight; neurophysiology; object recognition; receptive field; response; sample fixation; statistics; trend; visual stimulus

ABSTRACT In cluttered natural visual environments object recognition capacity can be severely limited. This may reflect limitations associated with the visual cortical encoding of multiple nearby stimuli. Alternatively, poor object recognition in clutter, especially profound in patients with autism, may result from limited resolution of attentional control and object decoding that rely on interactions between visual cortex and frontal cortex. We do not know what neuronal mechanisms limit object recognition in crowded scenes because neurophysiological studies typically present one or two stimuli at a time, and are thus free from the constraints imposed by clutter in natural scenes. In addition, studies seldom investigate the role of visual-frontal interactions in object recognition. We will use a combination of single neuron studies in awake monkeys, behavioral manipulations, reversible inactivation and computational modelling in two mid-level stages of visual cortex, V2 and V4, and the prefrontal cortex (PFC), to determine: (Aim 1) how V2 and V4 neurons encode visual stimuli in the presence of clutter, and how the encoding depends on eccentricity and on attentional engagement; (Aim 2) how PFC feedback influences encoding in V2 and V4, and how these brain regions together contribute to shape discrimination in clutter. We will consider three hypotheses. First, visual encoding may have limited resolution in clutter: when many objects are nearby, regardless of what those objects are, the visual system may fail to segment and encode individual objects. Second, processing in mid-level stages may be designed to encode only salient objects, i.e., objects that exhibit sufficient feature contrast relative to neighboring image regions. In this case, loss of information may pertain to objects in homogeneous image regions reflecting a representational strategy to preferentially encode objects that stand out. Third, it is possible that all objects are segmented and encoded faithfully, even in clutter, but the capacity limits are dictated by the resolution of attention or other downstream processes that influence object decoding. Our studies will address a fundamental gap in the understanding of how multi-objects displays, which dominate natural vision, are encoded in mid-level visual cortex. They will reveal how encoding strategies vary across eccentricity and this could be relevant for diseases like age-related macular degeneration, where foveal representations are compromised selectively. Finally, our results will provide fundamental insights into how V4 and PFC communication is critical for object recognition in clutter and how diminished communication between the two could influence behavior. This could be important for guiding translational work on autism spectrum disorder.

抽象的 在混乱的自然视觉环境中，物体识别能力可能受到严格限制。这可能反映了 与附近多个刺激的视觉皮质编码相关的局限性。或者，贫穷的物体 在自闭症患者中，杂物的认可，尤其是深刻的，可能是由于有限的分辨率而导致的 注意控制和对象解码依赖于视觉皮层和额叶皮质之间的相互作用。我们 不知道哪些神经元机制在拥挤的场景中限制了对象识别，因为 神经生理学研究通常一次提出一个或两个刺激，因此没有约束 在自然场景中被混乱施加。此外，研究很少研究视觉额外的作用 对象识别中的相互作用。我们将在清醒猴子中使用单个神经元研究的组合， 在两个中层阶段，行为操纵，可逆失活和计算建模 皮质，V2和V4以及前额叶皮层（PFC），以确定：（ AIM 1）V2和V4神经元如何编码 在杂乱的存在下，视觉刺激以及编码如何取决于偏心率和注意力 订婚; （AIM 2）PFC反馈如何影响V2和V4中的编码，以及这些大脑区域如何 共同有助于杂波中的歧视。我们将考虑三个假设。首先，视觉编码 混乱中的分辨率可能有限：当附近许多对象，无论这些对象是什么， 视觉系统可能无法细分并编码各个对象。其次，在中层阶段进行处理可能 被设计为仅编码显着对象，即相对于表现出足够特征对比的对象 相邻的图像区域。在这种情况下，信息丢失可能与均匀图像中的对象有关 区域反映了一种代表性策略，以优先编码突出的对象。第三，有可能 即使在混乱中，所有对象都会忠实地分割和编码，但是容量限制是由 注意力或其他影响对象解码的下游过程。我们的研究将解决 理解多对象显示方式（主导自然视野）的基本差距是 用中层视觉皮层编码。他们将揭示编码策略在偏心率之间的变化，这 可能与年龄相关的黄斑变性等疾病有关，在中央凹代表 选择性妥协。最后，我们的结果将提供有关V4和PFC的基本见解 通信对于混乱中的对象识别至关重要，以及两者之间的通信如何减少 可能影响行为。这对于指导自闭症谱系障碍的翻译工作可能很重要。