Development of function in extrastriate visual cortex

 描述（由申请人提供）：视觉神经科学的中心目标是了解大脑如何支持感知。研究大脑功能和感知之间关系的一个有效方法是研究发育过程中的并行过程。婴儿的视觉功能很差，并且根据视觉功能的类型出现不同的发育轨迹。不同功能的不同发育时间过程提供了一个独特的机会，直接评估大脑发育和感知之间的联系，提供了一个明确的假设的感知能力的神经基础。我们已经确定了对自然场景和视觉形式的感知与灵长类动物大脑中的V2和V4区域之间的联系。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和这些视觉区域的功能发展之间的联系。首先，我们将研究心理物理和非侵入性的高密度诱发反应措施的敏感性，纹理和形式的刺激纵向在个别婴儿猕猴，阐明这种感知能力的发展时间进程。我们提出将hdEEG检测作为心理物理学的辅助手段，可以将我们的结果直接与人类婴儿联系起来。第二，我们将直接评估神经生理学的发展的神经反应特性和感受野组织的V2区和V2神经元的特定反应相同的自然和自然的纹理刺激。我们将使用麻醉和清醒的准备充分表征这一过程。清醒记录将与行为测定同时在同一个体中进行，以直接 与行为和神经发育相关第三，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，以及区分适当形式刺激结构的能力。这些实验将促进我们对V2和V4在支持1）感知组织能力（如场景分割，物体识别和整体形式感知），2）初级视觉皮层和下游物体处理区域（如IT）之间的信息处理级联，以及3）神经发育对感知和认知发展的限制方面的作用的理解。我们更大的目标是阐明腹侧流处理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.