Mechanisms of Visual Motion Perception

视觉运动感知的机制

• 批准号: 8515419
• 负责人: Duje Tadin
• 金额: $ 24.66万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-01 至 2015-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8515419
• 关键词: Affect; Conflict (Psychology); Development; Discrimination; Elderly; Equilibrium; Exhibits; Face; Goals; Immune; Impairment; Individual; Individual Differences; Inherited; Intervention; Investigation; Knowledge; Lead; Link; Measures; Motion; Motion Perception; Neurons; Perception; Perceptual learning; Physiologic pulse; Process; Property; Psychophysics; Reflex action; Role; Signal Transduction; Staging; Stimulus; Sum; Testing; Transcranial magnetic stimulation; Variant; Vision; Visual; Visual Motion; Work; age related; area MT; base; cost; extrastriate visual cortex; improved; insight; interest; neuromechanism; oculomotor; public health relevance; relating to nervous system; segregation; spatial integration; spatial temporal variation; spatiotemporal; visual process; visual processing; young adult

DESCRIPTION (provided by applicant): Visual processing faces two conflicting demands: integration and segmentation. Integration is required by inherently noisy visual signals, while segmentation is needed to extract vital information from spatiotemporal variations in visual input. An understanding of the interplay between these two mechanisms will reveal fundamentals of visual processing and also enable insights into functional roles of segmentation processes. In motion perception, the PI's recent work demonstrated that spatial integration of motion signals is not fixed, but critically depends on basic visual factors such as contrast, with spatial integration giving way to spatial suppression as stimulus visibility increases. The overarching goal of this proposal is to investigate the neural mechanisms involved in this adaptive integration/segregation of motion signals, and to elucidate their role in the segmentation of objects from moving backgrounds. The key property of spatial suppression is impaired motion perception of large, high-contrast stimuli. In Aim 1, we will determine if and how this suppressive mechanism affects visual and oculomotor processing. Answering this question will constrain possible neural correlates of spatial suppression and, along with Aim 2, provide a test for the hypothesis linking spatial suppression to surround suppression in area MT. Substantiating this link will allow the attribution of links between spatial suppression and motion segregation (Aims 2 & 3) to the involvement of MT surround suppression. In Aim 2, we will seek direct evidence about neural correlates of spatial suppression by impairing processing in MT and early visual areas with TMS. We expect that a disruption of neural mechanisms critically involved in spatial suppression will allow normally suppressed motion signals to reach perception. Concurrently, we will also determine whether the same stimulation that impairs spatial suppression also disrupts motion segregation. In Aim 3, we test the hypothesis that spatial suppression directly enables rapid segregation of moving objects by suppressing background motion signals. Here, the role of spatial suppression in motion segregation is conceptualized as a coarse, but rapid, region-based segmentation process. This hypothesis predicts that variations in spatial suppression (and, thus, in the visibility of background motion) should predict corresponding changes in motion segregation and vice versa. Exploiting different experimental approaches, we will test this prediction by utilizing stimulus manipulations, individual differences and perceptual learning to produce variations in either spatial suppression or motion segregation. One focus will be on older adults, who are known to exhibit weak spatial suppression. We will determine whether this abnormality predicts motion segregation deficits and whether age-related deficits in spatial suppression can be reversed by the perceptual learning of motion segregation. PUBLIC HEALTH RELEVANCE: The knowledge of mechanisms underlying spatial suppression and motion segregation will contribute to the understanding of age-related changes in these two basic visual processes. Moreover, understanding how these age-related deficits can be alleviated through perceptual learning might lead to the development of viable interventions.

描述（由申请人提供）：视觉处理面对两个冲突的要求：集成和细分。积分是由固有嘈杂的视觉信号所需的，而需要分割来从视觉输入中的时空变化中提取重要信息。对这两种机制之间的相互作用的理解将揭示视觉处理的基本原理，并能够洞悉分割过程的功能作用。在运动感知中，PI最近的工作表明，运动信号的空间整合不是固定的，而是迫切地取决于基本的视觉因素，例如对比度，空间整合使空间抑制作用随着刺激可见性的提高而使位于空间抑制。该提案的总体目标是研究运动信号的适应性整合/隔离所涉及的神经机制，并阐明其在移动背景中对象分割中的作用。空间抑制的关键特性是大型高对比度刺激的运动感知受损。在AIM 1中，我们将确定这种抑制机制是否以及如何影响视觉和动眼处理。回答这个问题将限制空间抑制的可能的神经相关性，并与AIM 2一起对将空间抑制的假设进行测试，以围绕着区域MT的抑制。证实这种链接将允许在空间抑制和运动隔离（目标2和3）之间归因于MT环绕抑制的参与。在AIM 2中，我们将通过TMS的MT和早期视觉区域的处理来寻求有关空间抑制神经相关性的直接证据。我们预计，严重涉及空间抑制的神经机制的破坏将使通常抑制运动信号达到感知。同时，我们还将确定损害空间抑制的相同刺激是否也破坏了运动隔离。在AIM 3中，我们检验了以下假设：空间抑制直接通过抑制背景运动信号来快速隔离运动对象。在这里，空间抑制在运动分离中的作用被概念化为一个粗糙但基于区域的分割过程。该假设预测，空间抑制的变化（因此，在背景运动的可见性中）应预测运动分离的相应变化，反之亦然。利用不同的实验方法，我们将通过利用刺激操纵，个体差异和感知学习来测试这一预测，以在空间抑制或运动分离中产生变化。一个重点将放在老年人上，他们众所周知，他们表现出弱的空间抑制作用。我们将确定这种异常是否可以预测运动隔离缺陷，以及是否可以通过运动隔离的感知学习来逆转空间抑制中与年龄相关的缺陷。 公共卫生相关性：对空间抑制和运动隔离的机制的了解将有助于理解这两个基本视觉过程中与年龄相关的变化。此外，了解如何通过感知学习可以缓解这些与年龄相关的赤字可能导致可行的干预措施的发展。