High Spatial Frequency Acuity in Human Vision

人类视觉的高空间频率敏锐度

• 批准号: 6782047
• 负责人: STANLEY A KLEIN
• 金额: $ 29.86万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-07-01 至 2009-03-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6782047
• 关键词: amblyopia; behavioral /social science research tag; clinical research; discrimination learning; human subject; method development; neural information processing; neural plasticity; perceptual maskings; psychological tests; psychophysics; sensory discrimination; stimulus /response; visual perception; visual stimulus; visual threshold

DESCRIPTION (provided by applicant): Our previous research and that of others show that present models of visual processing are not satisfactory in suprathreshold vision, when a background is present. The proposed research seeks to advance our understanding of suprathreshold vision in known and unknown (noise) backgrounds. We seek to understand contrast processing, visual plasticity and long-range interactions using physiologically plausible mechanisms in normal and amblyopic subjects. Aim 1 develops and refines new methods for experimentally partitioning several factors of noise masking. A highly efficient procedure is introduced for measuring templates and noise in early stages of pattern processing. Aim 2 makes use of these methods for testing a number of hypotheses regarding the detection of a broad class of stimuli in noise. These results have relevance to our understanding of human spatial vision and to many real world tasks such as detecting tumors in medical images and image compression algorithms. Aim 3 is devoted to answering fundamental questions about the factors that limit our ability to perceive changes in contrast. Two types of perturbation will be used to isolate the underlying mechanisms of contrast processing: adaptation and long-range influences of surrounding stimuli. Special attention will be paid to the connection between the perceived contrast and the ability to distinguish contrasts of a test pattern. These studies will be specifically directed to making connections with findings from neurophysiology. Aim 4 applies the basic research findings from the previous aims to perceptual learning. Over the past decade evidence has been gathering that nervous system plasticity enables learning of pattern detection and discrimination with a specificity that indicates early or pre-decision stage learning. The proposed experiments carefully test the hypothesis that the learning is early rather than at the decision stage. Aim 5 applies our methods to gaining a deeper understanding of the amblyopic deficit. Of particular interest is the nature of the perceptual distortion at suprathreshold vision as a manifestation of early cortical organization. The understanding of spatial vision has progressed rapidly such that we can now accurately predict detection thresholds for arbitrary patterns on blank backgrounds using standard filter models. The proposed research will extend our understanding of spatial vision to suprathreshold levels where current models have limited utility. The focus is on understanding contrast processing, visual plasticity and long-range interactions in normal and amblyopic subjects, within a guiding framework of physiologically plausible mechanisms.

描述（由申请人提供）：我们以前的研究和其他研究表明，当存在背景时，目前的视觉处理模型在超股权视觉中并不令人满意。拟议的研究试图在已知和未知（噪声）背景中提高我们对远处远景的理解。我们寻求使用正常和弱视学科中生理上合理的机制来了解对比度处理，视觉可塑性和远程相互作用。 AIM 1开发并完善了新方法，以实验划分噪声掩盖的几个因素。引入了一个高效的程序，用于在模式处理的早期阶段测量模板和噪声。 AIM 2利用这些方法来测试有关检测噪声中广泛刺激的许多假设。这些结果与我们对人类空间视觉的理解以及许多现实世界任务相关，例如在医学图像和图像压缩算法中检测肿瘤。 AIM 3致力于回答有关限制我们感知对比变化能力的因素的基本问题。两种类型的扰动将用于隔离对比处理的潜在机制：适应和周围刺激的远程影响。将特别注意感知的对比与区分测试模式对比的能力之间的联系。这些研究将专门用于与神经生理学的发现建立联系。 AIM 4将以前目标的基础研究结果应用于感知学习。在过去的十年中，有证据表明，神经系统的可塑性可以通过表明早期或决策前学习的特异性来学习模式检测和歧视。提出的实验仔细检验了学习是早期而不是在决策阶段的假设。 AIM 5应用了我们的方法，以更深入地了解弱视赤字。特别感兴趣的是上股远景的感知失真的本质，作为早期皮质组织的体现。 对空间视觉的理解已经迅速发展，以便我们现在可以使用标准滤波器模型准确地预测空白背景上任意模式的检测阈值。拟议的研究将使我们对空间愿景的理解扩展到当前模型有限的效用有限的近路水平。重点是在生理上合理的机制的指导框架内理解对比处理，视觉可塑性和在正常和弱视主题中的远程相互作用。