NEURAL MECHANISMS OF SIZE PERCEPTION

尺寸感知的神经机制

• 批准号: 6164702
• 负责人: JOHN M ALLMAN
• 金额: $ 22.82万
• 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/6164702
• 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.

大小是对象的基本属性。 许多神经元非常 选择性的经典接受物体的大小 字段（CRF）;但是，对象大小的感知也取决于 视觉上下文，包括现场其他元素的大小和 对象与观察者的距离。我们建议调查 黄斑中尺寸感知的介导的机制 对象视觉的皮质区域的表示，V1，V2，V4，IT 醒着，表现出猕猴（Macaca Mulatta）。在我们的初步中 研究我们发现了2个主要距离调制神经元的主要类别：接近度 响应随着猴子的接近而增加的细胞，并且 响应随着距离距离而增加的范围单元 猴。这些神经元通常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 距离，还搜索表现出真正大小恒定的神经元， 即在不同距离下调整为绝对对象大小的单元。 我们还计划通过参与来测试注意力的影响 大小比较任务的猴子。 我们将确定视觉上下文如何影响 CRF内呈现的不同尺寸刺激的神经元。我们计划2 通过Ebbinghaus幻觉和 虚拟实验室。这些都提供了一种探测非 - 的方法 经典的接受场（非CRF）揭示其在机制中的作用 大小感知。对象的感知大小受到 Ebbinghaus幻觉中周围物体的大小。我们将测试 非CRF在尺寸选择性细胞中的影响通过呈现不同 在测量反应的同时，周围的尺寸和形状的刺激 在CRF内呈现的不同尺寸的刺激。在另一个测试中 视觉背景的影响，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 深度和透视图可以作为独立参数来测试 这些线索对猴子对大小的看法以及 它们对神经元距离调制或大小恒定的影响 在V1，V2，V4和IT中。我们还将测试双眼差的影响 并带有电线框样式图像的透视图，背景 阴影和纹理将从计算机图形显示中删除。 最后，我们将通过掩盖绘制周围非CRF的范围 视觉上下文显示的一部分，同时衡量对 CRF内呈现不同尺寸的刺激。