Visual processing of contours and textures

轮廓和纹理的视觉处理

• 批准号: RGPIN-2016-03915
• 负责人: Kingdom, Frederick
• 金额: $ 2.99万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=614717
• 关键词: Visual; processing; contours; textures

This application is for funds to continue my studies into the visual processing of contours and textures. The visual ability to detect the shapes of contours, such as the outline of a pear, and the structure of textures, such as the pattern on a carpet or the bark of a tree, is essential for recognizing patterns, objects and the shapes of textured surfaces. My experiments use behavioural or ‘psychophysical’ methods with normal human test subjects. In a typical experiment, subjects view large numbers of specially-designed computer-generated test patterns presented on a display monitor and are required to make for each a forced-choice judgement; for example which of two shapes is the one previously shown, which of two patterns is the more regularly arranged, which of two textures contains a circular structure. One of my experimental methods also exploits a phenomenon termed the ‘visual after-effect’. Prolonged viewing, termed ‘adaptation’, of a particular contour shape or texture causes subsequently presented contours/textures to appear distorted. By measuring the amount of distortion, much can be learnt about how the brain processes contour and texture information. For example, a fundamental feature of texture patterns is regularity, or ‘repeatedness’, for example as in the repeating pattern of a carpet. If one takes a highly regular texture pattern, such as an array of dots arranged perfectly on a grid, and adapts to it, a slightly less regular pattern appears even less regular than otherwise. This effect is termed the ‘regularity after-effect’, and the fact that it happens at all suggests that there are neurons in the brain that are specialized for seeing regularity. By measuring the regularity aftereffect for various types of texture pattern and constructing computer models of how the neurons might encode regularity, one can work out how the brain detects and encodes regularity in a texture pattern. Together with my other experiments on shape coding and texture, my research will therefore lead to a better understanding of how the brain sees the shapes of contours and the structure of textures.

这个应用程序是资金继续我的研究到视觉处理的轮廓和纹理。检测轮廓形状（如梨的轮廓）和纹理结构（如地毯或树皮上的图案）的视觉能力对于识别图案、物体和纹理表面的形状至关重要。我的实验使用行为或“心理物理”方法，以正常的人类测试对象为对象。在一个典型的实验中，受试者观看大量专门设计的计算机生成的测试图案，这些图案呈现在显示器上，受试者需要对每个图案进行强制选择判断;例如，两个形状中的哪一个是先前显示的那个，两个图案中的哪一个排列得更规则，两个纹理中的哪一个包含圆形结构。我的一个实验方法也利用了一种被称为“视觉后效应”的现象。对特定轮廓形状或纹理的长时间观察（称为“适应”）导致随后呈现的轮廓/纹理看起来失真。通过测量失真的量，可以了解大脑如何处理轮廓和纹理信息。例如，纹理图案的基本特征是规则性或“重复性”，例如地毯的重复图案。如果一个人采取了一个高度规则的纹理模式，如一个完美地排列在网格上的点阵列，并适应它，一个稍微不规则的模式看起来甚至比其他更不规则。这种效应被称为“规律性后效应”，它的发生表明大脑中有专门用于观察规律性的神经元。通过测量不同类型纹理图案的规律性后效，并构建神经元如何编码规律性的计算机模型，人们可以了解大脑如何检测和编码纹理图案中的规律性。再加上我在形状编码和纹理方面的其他实验，我的研究将有助于更好地理解大脑如何看待轮廓的形状和纹理的结构。