Quantitative Studies of Visual Pathways

描述（由申请人提供）：总体目标是了解外侧膝状体核（LGN）和视觉皮层中的机制如何分析有关物体颜色特性的信息，以及这些机制如何决定人类感知能力。提出了三组密切相关的生理学研究。第一组将通过实验和建模建立LGN和皮层神经元感受野中颜色选择性的基本组织。这些研究将回答以下问题：在何种程度上的颜色属性的感受野结果从选择的输入锥的特定类别与选择的输入锥在特定的位置;如何沉默的区域周围的感受野形状神经元的颜色选择性;做对比度的变化改变神经元的颜色选择性？第二组的研究将在皮层神经元的感受野的颜色属性和双目属性之间的关系的特点。一项研究将揭示神经元是否以及如何协调相互冲突的要求，即它们的两个感受野具有匹配的空间特性和匹配的色彩特性;另一项研究将揭示双眼驱动神经元如何联合收割机组合两只眼睛中产生的不同颜色信号。这些研究是理解双眼颜色混合的核心。第三组研究将描述色彩适应机制，深刻影响色彩敏感性和外观。一项研究将分析LGN神经元中表达的早期信号转换，这些转换是由适应平均色度带来的;另一项研究将分析皮层中发生的后续转换--既有适应平均色度带来的转换，也有适应色彩对比度带来的转换。

DESCRIPTION (provided by applicant): The overall aim is to understand how mechanisms in the lateral geniculate nucleus (LGN) and visual cortex analyze information about the chromatic properties of objects, and how these mechanisms determine human perceptual capabilities. Three closely connected groups of physiological studies are proposed. The first group will establish, through experiment and modeling, the underlying organization of chromatic selectivity in the receptive fields of neurons in LGN and cortex. The studies will answer the following questions: to what extent do the chromatic properties of a receptive field result from selection of inputs from cones of particular classes vs. selection of inputs from cones in particular positions; how does the silent region surrounding the receptive field shape a neuron's chromatic selectivity; do variations in contrast alter the chromatic selectivity of neurons? The second group of studies will characterize in cortical neurons the relationship between the chromatic properties and the binocular properties of receptive fields. One study will reveal whether and how neurons reconcile the conflicting demands that their two receptive fields have matched spatial properties and also matched chromatic properties; another will reveal how binocularly driven neurons combine different color signals arising in the two eyes. These studies are central to understanding binocular color mixture. The third group of studies will characterize mechanisms of chromatic adaptation that profoundly influence color sensitivity and appearance. One study will analyze the early signal transformations, expressed in LGN neurons, that are brought about by adaptation to mean chromaticity; another will analyze the subsequent transformations that occur in cortex--both those brought about by adaptation to the mean chromaticity, and those brought about by adaptation to chromatic contrast.