NEURAL MECHANISMS OF SIZE PERCEPTION

尺寸感知的神经机制

• 批准号: 2668416
• 负责人: JOHN M ALLMAN
• 金额: $ 21.14万
• 依托单位: CALIFORNIA INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-03-01 至 2002-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2668416
• 关键词: Macaca mulatta; attention; behavior test; behavioral /social science research tag; binocular vision; computer graphics /printing; magnetic resonance imaging; neural information processing; neurophysiology; size perception; visual cortex; visual depth perception; visual fields; visual pathways; visual perception; visual stimulus

Size is a fundamental attribute of objects. Many neurons are very selective for the size of objects presented in their classical receptive fields (CRFs); however, the perception of object size also depends on the visual context including the size of other elements in the field and the distance of the object from the observer. We propose to investigate the mechanisms for the mediation of size perceptIon in the macular representations in cortical areas for object vision, V1, V2, V4, and IT in awake, behaving macaque monkeys (Macaca mulatta). In our preliminary studies we found 2 main classes of distance modulated neurons: nearness cells in which the response increases with proximity to the monkey, and farness cells in which the response increases with distance from the monkey. These neurons typically are tuned to the same retinal image size at different distances. We will complete our survey of the influence of distance and also search for neurons that exhibit true size constancy, i.e. cells that are tuned to absolute object size at different distances. We also plan to test for the possible influence of attention by engaging the monkeys in size comparison tasks. We will determine how the visual context influences the responses of neurons to different sized stimuli presented within the CRF. We plan 2 approaches to this problem through the Ebbinghaus illusion and the virtual laboratory. Each of these provides a way to probe the non- classical receptive field (non-CRF) to reveal its role in the mechanisms of size perception. The perceived size of objects is influenced by the size of surrounding objects in the Ebbinghaus illusion. We will test the influence of the non-CRF in size-selective cells by presenting different sized and shaped stimuli in the surround while measuring the responses to different sized stimuli presented within the CRF. In another test of the influence of the visual context, we will create a virtual laboratory in the form of a computer graphics model of our actual experimental set- up. The advantage of the computer graphics model is that stereoscopic depth and perspective can be varied as independent parameters to test the influence of these cues on the monkey's perception of size as well as their influence on the distance modulation or size constancy of neurons in V1,V2,V4 and IT. We will also test the effects of binocular disparity and perspective with wire-frame style images in which color, background shading and texture will be removed from the computer graphics display. Finally, we will map the extent of the surrounding non-CRF by masking parts of the visual contextual display while measuring the responses to different sized stimuli presented within the CRF.

大小是物体的基本属性。 许多神经元非常 对经典接受中呈现的物体的大小有选择性 字段（CRF）；然而，对物体大小的感知也取决于 视觉上下文，包括字段中其他元素的大小和 物体与观察者的距离。我们建议调查 黄斑区大小知觉的调节机制 物体视觉、V1、V2、V4 和 IT 皮质区域的表征 处于清醒状态、行为举止的猕猴（Macaca mulatta）。在我们的初步 研究我们发现了两类主要的距离调节神经元：接近度 细胞中的反应随着接近猴子而增加，以及 距离细胞，其中响应随着距物体的距离而增加 猴。这些神经元通常被调整为相同的视网膜图像大小 在不同的距离。我们将完成对影响力的调查 距离并搜索表现出真实大小恒定性的神经元， 即在不同距离处调整为绝对物体尺寸的细胞。 我们还计划通过参与来测试注意力的可能影响 猴子在进行大小比较任务。 我们将确定视觉环境如何影响人们的反应 神经元对 CRF 内呈现的不同大小的刺激。我们计划2 通过艾宾浩斯错觉和 虚拟实验室。其中每一个都提供了一种探测非 经典感受野（非 CRF）揭示其在机制中的作用 的尺寸感知。物体的感知大小受以下因素影响 艾宾浩斯错觉中周围物体的大小。我们将测试 通过呈现不同的尺寸选择性细胞中非 CRF 的影响 在测量反应的同时调整周围环境刺激的大小和形状 CRF 中呈现的不同大小的刺激。在另一次测试中 视觉语境的影响，我们将创建一个虚拟实验室 以我们实际实验集的计算机图形模型的形式- 向上。计算机图形模型的优点是立体 深度和视角可以作为独立参数进行变化，以测试 这些线索对猴子对大小的感知以及 它们对神经元的距离调制或大小恒定性的影响 在 V1、V2、V4 和 IT 中。我们还将测试双眼视差的影响 和线框风格图像的透视，其中颜色、背景 阴影和纹理将从计算机图形显示中删除。 最后，我们将通过掩蔽来映射周围非CRF的范围 视觉上下文显示的一部分，同时测量对 CRF 中呈现不同大小的刺激。