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.

摘要 在杂乱的自然视觉环境中，物体识别能力可能受到严重限制。这可能反映 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 在混乱中的识别，尤其是自闭症患者的深刻，可能是由于有限的分辨率， 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 我不知道是什么神经机制限制了拥挤场景中的物体识别， 神经生理学研究通常一次呈现一个或两个刺激，因此不受限制。 由自然场景中的杂乱所造成。此外，研究很少探讨视觉额叶的作用， 物体识别中的相互作用。我们将在清醒的猴子中使用单个神经元研究的组合， 行为操纵，可逆失活和计算建模在两个中级阶段的视觉 皮层，V2和V4，以及前额叶皮层（PFC），以确定：（目的1）V2和V4神经元如何编码 在混乱的存在下的视觉刺激，以及编码如何依赖于偏心率和注意力 （目标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 一起有助于在杂波中的形状辨别。我们将考虑三个假设。第一，视觉编码 在杂乱中可能具有有限的分辨率：当许多对象在附近时，无论这些对象是什么， 视觉系统可能无法分割和编码单个对象。第二，中级阶段的处理可能 被设计为仅对显著对象进行编码，即，显示出足够的特征对比度的对象， 相邻图像区域。在这种情况下，信息的丢失可能与均匀图像中的对象有关 反映优先编码突出的对象的代表性策略的区域。三是可以 所有对象都被忠实地分割和编码，即使在混乱中，但容量限制由 注意力的分解或影响对象解码的其他下游过程。我们的研究将解决 在理解主宰自然视觉的多物体显示器如何 编码在中层视觉皮层中他们将揭示编码策略如何在偏心率上变化， 可能与老年性黄斑变性等疾病有关， 选择性妥协最后，我们的研究结果将为V4和PFC 通信对于在杂乱中识别物体至关重要， 可以影响行为。这对于指导自闭症谱系障碍的翻译工作可能很重要。