Motion Processing System in Schizophrenia

描述(由申请人提供)：这是一份竞争性的续期研究资助申请(精神分裂症的运动处理系统R01，MH 61824)。在上一次资助期间(2000-2003)，我们研究了精神分裂症患者典型视觉运动过程的功能特性。我们发现，精神分裂症患者运动系统的整体阶段，而不是局部阶段受到了损害，这意味着纹外皮质的神经处理有缺陷。我们发现精神分裂症患者的运动加工缺陷与视觉对比度调制无关，这表明运动通路中对比度无关的晚期受到影响。鉴于纹外皮质运动处理的后期阶段调节了运动信号的空间和时间整合，从我们的发现中得出的一个普遍假设是，与精神分裂症有关的视觉大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了解。以视觉神经生理学发展的原理为指导，拟议的研究将通过研究精神分裂症患者和非精神分裂症患者的视觉系统的空间结构和时间结构，重点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的。我们将确定感觉、运动和认知对空间和时间近似性不同的配对和分组的视觉刺激的反应。我们将确定视觉大脑对运动辨别事件的反应模式。这些研究的结果将表明精神分裂症患者视觉系统不同加工成分之间的空间和时间相互作用是如何发挥作用的，由此可以经验性地评估“整体与部分之和”假说。

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.