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: 9759575
• 负责人: Anitha Pasupathy
• 金额: $ 59.72万
• 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 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9759575
• 关键词: Address; Affect; Age related macular degeneration; Agnosia; Animal Behavior; Animals; Area; Attention; Behavior; Behavior Control; Behavioral; Behavioral Paradigm; Brain Diseases; Brain region; Child; Clutterings; Communication; Communication impairment; Computer Simulation; 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; V2 neuron; V4 neuron; Vision; Visual; Visual Cortex; Visual Pathways; Visual system structure; Work; area V2; area V4; attentional control; autism spectrum disorder; awake; base; behavior influence; design; experimental study; extrastriate visual cortex; fovea centralis; frontal lobe; human subject; inattentional blindness; insight; neurophysiology; object recognition; receptive field; response; 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 在杂乱的自然视觉环境中，物体识别能力可能会受到严重限制。这可能反映出 与多个附近刺激的视觉皮层编码相关的限制。或者，可怜的对象 杂乱中的识别能力，对于自闭症患者来说尤其深刻，可能是由于有限的分辨率造成的 注意力控制和物体解码依赖于视觉皮层和额叶皮层之间的相互作用。我们 不知道什么神经机制限制了拥挤场景中的物体识别，因为 神经生理学研究通常一次呈现一种或两种刺激，因此不受限制 自然场景中的杂乱所造成的。此外，研究很少调查视觉额叶的作用 物体识别中的交互。我们将结合对清醒猴子的单个神经元研究， 视觉的两个中级阶段的行为操纵、可逆失活和计算建模 皮层、V2 和 V4 以及前额叶皮层 (PFC)，以确定：（目标 1）V2 和 V4 神经元如何编码 杂乱情况下的视觉刺激，以及编码如何取决于偏心率和注意力 订婚; （目标 2）PFC 反馈如何影响 V2 和 V4 的编码，以及这些大脑区域如何影响 共同造成杂乱中的形状歧视。我们将考虑三个假设。一、视觉编码 杂乱情况下的分辨率可能有限：当附近有许多物体时，无论这些物体是什么， 视觉系统可能无法对单个对象进行分割和编码。其次，中层阶段的处理可能 被设计为仅对显着对象进行编码，即相对于显着对象表现出足够特征对比度的对象 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 反映优先编码突出对象的代表性策略的区域。三、有可能 即使在杂乱的情况下，所有对象都被忠实地分段和编码，但容量限制由 注意力的解决或影响对象解码的其他下游过程。我们的研究将解决 对主导自然视觉的多对象显示如何进行理解存在根本差距 编码于中层视觉皮层。他们将揭示编码策略如何因偏心率而变化，并且这一点 可能与年龄相关性黄斑变性等疾病有关，其中黄斑中心凹代表 有选择地妥协。最后，我们的结果将为 V4 和 PFC 如何提供基本见解 通信对于杂乱中的物体识别至关重要，以及两者之间的通信如何减少 可能会影响行为。这对于指导自闭症谱系障碍的转化工作可能很重要。