Motion Processing System in Schizophrenia

描述（由申请人提供）：这是一份研究资助（精神分裂症运动处理系统R01 MH 61824）的竞争性续期申请。在最后一个资助期（2000-2003），我们检查了精神分裂症中代表性视觉运动过程的功能特性。我们发现，在精神分裂症患者中，运动系统的整体阶段而非局部阶段受到损害，这意味着纹状体外皮层的神经处理出现了缺陷。我们发现精神分裂症患者的运动加工缺陷是独立于视觉对比度调制的，这表明运动通路的对比度独立的后期阶段受到影响。考虑到颅外皮层的运动处理后期调节运动信号的时空整合，我们的研究结果提出了一个普遍的假设，即与精神分裂症有关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，整体不等于部分的总和。在过去的几十年里，视觉神经科学的进步极大地增加了人们对大脑系统不同部分如何协同工作的认识。以视觉神经生理学原理为指导，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是如何在功能上组织起来的。我们将确定对配对和分组视觉刺激的感觉、运动和认知反应，这些视觉刺激的空间和时间接近度是系统变化的。我们将确定对运动辨别事件作出反应的视觉脑激活模式。这些研究的结果将表明，在精神分裂症患者的视觉系统的不同处理组件之间的空间和时间的相互作用是如何运作的，由此“整体与部分之和”的假设可以被经验地评估。

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.