Motion Processing System in Schizophrenia

描述（由申请人提供）：这是一个有竞争力的更新申请研究补助金（运动处理系统在精神分裂症R 01 MH 61824）。在上一个资助期（2000-2003年），我们研究了精神分裂症的代表性视觉运动过程的功能特性。我们发现，精神分裂症患者的运动系统的整体而非局部阶段受损，这意味着纹外皮层的神经处理有缺陷。我们发现，精神分裂症的运动处理缺陷是独立的视觉对比度调制，这表明对比度独立的运动通路的后期受到影响。鉴于纹状体外皮层运动处理的后期阶段介导了运动信号的空间和时间整合，我们的研究结果产生的一个普遍假设是，精神分裂症中涉及的视觉脑系统无法作为一个整体发挥作用。也就是说，在精神分裂症的大脑系统中，整体并不等于部分之和。视觉神经科学在过去几十年中的进步极大地增加了关于大脑系统不同部分如何协同工作的知识。以视觉神经生理学的原理为指导，通过研究精神分裂症患者和非精神分裂症患者视觉系统的空间和时间结构，研究精神分裂症患者视觉系统的不同组成部分在功能上是如何组织的。我们将确定感觉，运动和认知反应成对和分组的视觉刺激的空间和时间的接近度是系统地变化。我们将确定视觉大脑激活的模式，以响应运动辨别事件。这些调查的结果将表明如何在精神分裂症患者的视觉系统功能的不同处理组件的空间和时间的相互作用，从“整体与部分的总和”的假设可以进行经验评估。

DESCRIPTION (provided by applicant): This is a competitive renewal application for a research grant (Motion Processing System in Schizophrenia R01 MH 61824). In the last grant period (2000-2003), we examined functional properties of representative visual motion processes in schizophrenia. We found that the global, but not the local, stages of the motion system are impaired in schizophrenia, which implicates faulty neural processing in the extrastriate cortex. We found that the motion-processing deficit in schizophrenia is independent of visual contrast modulation, suggesting that the contrast-independent late stage of the motion pathway is affected. Given that the late stages of motion processing in the extrastriate cortex mediate spatial and temporal integration of motion signals, one general hypothesis arising from our findings is that the visual brain system implicated in schizophrenia is unable to function as an ensemble. That is, the whole is not equal to the sum of the parts, in the context of the schizophrenic brain system. The advances of visual neuroscience in the past decades have greatly increased the knowledge about how the different parts of the brain system work together. With the principles developed in visual neurophysiology as a guideline, the proposed studies will focus on how different components of the visual system in schizophrenia are functionally organized, through studying its spatial and temporal structures in individuals with and without schizophrenia. We will determine sensory, motor, and cognitive responses to paired and grouped visual stimuli whose spatial and temporal proximities are systematically varied. We will determine the pattern of visual brain activation in response to motion discrimination events. The outcome of these investigations will indicate how the spatial and temporal interaction across the different processing components of the visual system functions in schizophrenic patients, from which the "whole vs. sum of the parts" hypothesis can be evaluated empirically.