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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

基本信息

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
项目类别：
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

项目摘要

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