Development of function in extrastriate visual cortex

 描述(申请人提供)：视觉神经科学的一个中心目标是了解大脑如何支持知觉。研究大脑功能和知觉之间关系的一个强有力的方法是并行研究发育过程中的过程。婴儿的视觉功能很差，根据视觉功能的类型，会出现不同的发育轨迹。不同功能的不同发育时间进程为直接评估大脑发育和知觉之间的联系提供了独特的机会，前提是对知觉能力的神经基础有一个明确的假设。我们已经确定了对自然场景的感知和视觉形式以及灵长类动物大脑中的V2和V4区域之间的这种联系。我们提出了三组相互关联的实验，以探索自然纹理敏感性的发展与这些视觉区域的功能发展之间的联系。首先，我们将研究个体幼猴对质地和形状刺激的纵向敏感的心理物理和非侵入性高密度诱发反应测量，以阐明这种知觉能力的发育时间进程。我们建议hdEEG测试作为心理物理学的一个补充，它可以将我们的结果直接与人类婴儿联系起来。其次，我们将直接从神经生理学的角度评估V2区神经反应特性和感受野组织的发展，以及V2神经元对相同的自然和自然纹理刺激的特定反应。我们将使用麻醉和清醒准备来充分描述这一过程。清醒录音将与同一个体的行为分析并行进行，以直接 将行为和神经发育联系起来。第三，我们将研究V4区对自然场景的神经敏感性的发展及其潜在的统计特性，以及它们区分合适形式刺激结构的能力。这些实验将促进我们理解V2和V4在支持1)知觉组织能力方面的作用，如场景分割、物体识别和全局形状感知，2)初级视觉皮质和下游物体加工区域(如IT)之间的信息处理级联，以及3)神经发育对知觉和认知发展的限制。我们更大的目标是阐明腹侧流形成信息和解析自然场景的机制。

 DESCRIPTION (provided by applicant): A central goal of visual neuroscience is to understand how the brain supports perception. A powerful approach to studying the relationship between brain function and perception is to study the processes in parallel during development. Visual function is poor in infants and emerges over different developmental trajectories depending on the type of visual function. The distinct developmental time courses for different functions provide a unique opportunity to directly evaluate the link between brain development and perception, provided there is a clear hypothesis about the neural underpinnings of the perceptual ability. We have identified such a connection between perception of natural scenes and visual forms, and areas V2 and V4 in the primate brain. We propose three interrelated sets of experiments to explore the links between the development of naturalistic texture sensitivity and the functional development of these visual areas. First, we will study psychophysical and non-invasive high-density evoked response measures of sensitivity to texture and form stimuli longitudinally in individual infant macaques, to elucidate the developmental time courses for this perceptual ability. We propose the hdEEG assay as an adjunct to the psychophysics which can bridge our results directly to human infants. Second, we will directly assess neurophysiologically the development of neural response properties and receptive field organization of area V2 and the specific responses of V2 neurons to the same natural and naturalistic texture stimuli. We will use both anesthetized and awake preparations to fully characterize this process. The awake recordings will be conducted in parallel with behavioral assays in the same individuals to directly correlate behavioral and neural development. Third, we will study the development of neural sensitivity of area V4 to natural scenes and their underlying statistical properties, as well as thir ability to differentially signal the structure of suitable form stimuli. These experiments will advance our understanding of the role of V2 and V4 in support of 1) perceptual organization abilities, such as scene segmentation, object recognition, and global form perception, 2) the cascade of information processing between primary visual cortex and downstream object processing areas such as IT, and 3) the limitations that neural development pose on the development of perception and cognition. Our greater goal is to elucidate the mechanisms by which the ventral stream processes form information and parses natural scenes.