Interactions between afferent channels in vision: basic neurophysiology and implications for the pathology of dyslexia

视觉传入通道之间的相互作用：基础神经生理学及其对阅读障碍病理学的影响

• 批准号: nhmrc : 122809
• 负责人: Prof Trichur Vidyasagar
• 金额: $ 28.25万
• 依托单位国家: 澳大利亚
• 项目类别: NHMRC Project Grants
• 财政年份: 2000
• 资助国家: 澳大利亚
• 起止时间: 2000-01-01 至 2002-12-31
• 项目状态: 已结题
• 来源: https://researchdata.edu.au/interactions-afferent-channels-pathology-dyslexia/82243
• 关键词: Interactions; between; afferent; channels; vision

We intend to study the interactions between different information channels in the primate visual system. The pathways from the eyes to the brain consist of different types of nerve fibres carrying distinct sorts of information. These channels have been believed to remain separate as they transmit the information through various levels of the brain. Finally, in the neocortex, it has been suggested that the visual information goes along two major streams, one dorsally to the parietal cortex and the other ventrally to the temporal cortex. Based upon recent studies, we question this strict segregation of the pathways and propose to study how interactions occur between the two streams and whether the two channels do come together at early levels of the visual pathway. We will also test our idea whether, of the dorsal and ventral streams, one stream might actually gate the other and decide what goes through the other stream. In fact, from our own recent studies, we have reason to believe that the way our attentional system might operate to select salient aspects of the visual scene may be through the dorsal stream selecting what goes into the ventral stream, which seems to be responsible for identifying objects. In the proposed project we will test this idea rigorously. From various lines of evidence, we also argue that the neural mechanisms that underlie this attentional spotlight is exploited by human children when they learn to read. It follows that any defect in the dorsal pathway or in the fibres and cells that feed into this will cause difficulties in reading. We believe this to be the underlying problem in dyslexic children. The project will undertake a number of experiments to test this idea.

我们打算研究灵长类视觉系统中不同信息通道之间的相互作用。从眼睛到大脑的通路由不同类型的神经纤维组成，这些神经纤维承载着不同种类的信息。这些通道一直被认为是分开的，因为它们通过大脑的不同级别传输信息。最后，在新大脑皮层，有研究表明，视觉信息沿着两条主要路线传递，一条是背侧到达顶叶皮质，另一条是腹侧到达颞叶皮质。基于最近的研究，我们对这种严格的通路分离提出了质疑，并建议研究两个通道之间是如何发生相互作用的，以及两个通道是否在视觉通道的早期水平结合在一起。我们还将测试我们的想法，在背侧和腹侧的溪流中，一条溪流是否真的会连接另一条溪流，并决定另一条溪流流经的是什么。事实上，从我们自己最近的研究中，我们有理由相信，我们的注意力系统可能通过背流来选择视觉场景的显著方面，选择进入腹流的东西，这似乎负责识别物体。在提议的项目中，我们将严格测试这一想法。从各种证据来看，我们还认为，人类儿童在学习阅读时，利用了这种注意力聚光灯下的神经机制。因此，背侧通路或进入背侧通路的纤维和细胞的任何缺陷都会导致阅读困难。我们认为这是阅读障碍儿童的根本问题。该项目将进行一系列实验来检验这一想法。