DEVELOPMENT OF VISUAL EFFICIENCY

这项研究的目的是揭示神经机制。 这限制了灵长类动物视觉表现的发展。近期 视觉心理物理学和理论的进步使我们有可能 用相同的术语阐述关于视觉发展的问题 分析成年人的视力，我们正在进行实验，探索 神经生物学在这些功能方面的发展。这个 本项目中的实验以视觉测量为关键 效率，即在视觉中编码对比度的保真度 系统。对比阈值在存在或存在的情况下测量的行为 对幼年猕猴的无掩蔽噪声进行了评估 年纪大了。我们证实，随着动物的成熟，视觉效率 提高对比度敏感度。试图建立起 我们从外侧膝状体神经元记录的潜在机制 新生儿视神经核团(LGN)和初级视皮层(V1)。我们发现 在灵敏度和分辨率方面的改进程度 LGN中的神经元不够丰富，不足以解释 行为测量的变化。我们在V1中的录音到目前为止还很 初步的，但我们预计会在 V1比我们在LGN水平上发现的。除了这些之外， 研究表明，我们已经开始测量对 灵长类动物的视觉运动。我们计划研究视觉的成熟度 大脑皮质中的运动处理区域，以了解成熟的 婴儿视觉运动处理的基础过程。

The goal of this research is to uncover the neuronal mechanisms that limit the development of visual performance in primates. Recent advances in visual psychophysics and theory have made it possible to formulate questions about visual development in the same terms used to analyze adult vision, and we are conducting experiments to explore the neurobiology of development in these functional terms. The experiments in this project hinge on the measurement of visual efficiency, the fidelity with which contrast is encoded in the visual system. Contrast thresholds measured behaviorally in the presence or absence of masking noise are assessed in infant macaques as a function of age. We confirmed that, as the animals mature, visual efficiency improves with contrast sensitivity. To try to establish the underlying mechanisms we recorded from neurons in lateral geniculate nucleus (LGN) and primary visual cortex (V1) in newborns. We found that the degree of improvement in sensitivity and resolution of neurons in LGN was not substantial enough to account for the behaviorally measured changes. Our recordings in V1 are as yet quite preliminary, but we expect to find a greater degree of maturation in V1 than we found at the level of the LGN. In addition to these studies, we have begun to measure the development of sensitivity to visual motion in primates. We plan to study the maturation of visual motion processing areas in the cortex to understand the maturational processes that underlie visual motion processing in infants.