Visual tuning and performance in schizophrenia and bipolar disorder

描述（由申请人提供）：精神分裂症（SZ）的视觉处理异常是普遍存在的，在各种范式中都可以看到，并且通常程度很大。尽管它们具有信息价值，但与额叶和颞叶皮质系统相关的损伤相比，这些损伤受到的研究关注要少得多。视觉加工范式通常具有完善的神经基础，为研究SZ的神经功能提供了直接途径。部分由于研究重点的减少，我们的知识存在根本性的差距。其中一个缺口是缺乏一个完整的理论来令人满意地解释视觉处理测量范围内的发现模式。其次，我们不知道视觉处理障碍在慢性精神疾病诊断中的延伸程度，包括SZ和双相情感障碍（BD）。虽然在双相障碍中发现了视觉处理异常，但很少有人尝试在视觉处理阶段详细检查双相障碍的表现。目前的应用将测试一个核心过程的理论，该理论可能有助于解释SZ和BD中观察到的视觉处理障碍的范围。我们假设，我们实验室和其他人的一系列发现可能最简单地解释为神经元对物体特征的调节异常（即，神经元对首选视觉物体产生特定神经反应的能力低于视觉相似的物体，称为“视觉调节”）。对物体或物体特征的视觉处理发生在外侧枕复合体（LO）。虽然关于BD的视觉加工异常的文献比SZ少，但这种损伤已经被发现。目前的应用程序将评估这种缺陷是否也源于视觉调节问题。该研究将招募90名SZ患者、90名BD患者和90名健康对照者，这些患者将在关键人口统计学变量上进行分组匹配。受试者将参与知觉表现，电生理（EEG），认知和功能磁共振成像（fMRI）程序，以实现以下三个目标：1)使用专门的EEG和fMRI方法检查SZ的视觉神经调谐；2)采用专门的EEG和fMRI方法检测SZ、BD和健康对照的视觉神经调谐交叉诊断；3)探讨视觉调节缺陷在SZ、BD和健康对照中的意义，包括知觉、高级认知和功能。该研究计划与NIMH战略计划和NIMH研究领域标准项目的几个组成部分是一致的。本研究项目的结果将有助于了解SZ和BD在视觉加工方面的异同，以及这些条件下视觉加工障碍的潜在神经基质。视觉调节是可修改的，并且可以在人类和动物中可靠地评估，因此这一信息将对治疗开发产生影响。

DESCRIPTION (provided by applicant): Visual processing abnormalities in schizophrenia (SZ) are pervasive, seen in a variety of paradigms, and typically large in magnitude. Despite their informative value, these impairments have received far less research attention than impairments associated with frontal and temporal cortical systems. Visual processing paradigms often have well-established neural bases and provide a direct way to investigate neural functioning in SZ. Partly as a result of reduced research emphasis there are fundamental gaps in our knowledge. One such gap is the absence of an integrated theory that satisfactorily explains the patterns of findings across the range of visual processing measures. A second is that we do not know the degree to which visual processing impairment extends across diagnoses for chronic mental illness, including SZ and bipolar disorder (BD). Although abnormalities in visual processing have been found in BD, few attempts have been made to examine performance in BD in a detailed manner across visual processing stages. The current application will test a theory of a core process that might help explain the range of visual processing impairment observed in SZ and BD. We hypothesize that an array of findings from our laboratory, and others, might be explained most parsimoniously as an abnormality in the tuning of neurons for object features (i.e., neurons are less able to generate specific neural responses to preferred visual objects versus visually similar objects; referred to as "visual tuning"). Visual processing for objects or object features occurs in the lateral occipital complex (LO). Although the literature on visual processing abnormalities in BD is smaller than that in SZ, such impairments have been found. The current application will evaluate whether such deficits in BD also stem from problems in visual tuning. The proposed study will recruit 90 SZ patients, 90 BD patients and 90 healthy controls that will be group- matched on key demographic variables. The subjects will participate in perceptual performance, electrophysiological (EEG), cognition, and functional magnetic resonance imaging (fMRI) procedures to address the following three aims: 1) To examine visual neural tuning in SZ using specialized EEG and fMRI methods; 2) To examine visual neural tuning cross-diagnostically among SZ, BD, and healthy controls with specialized EEG and fMRI methods; and 3) To examine the implications of visual tuning deficits in SZ, BD, and healthy controls, including perception, higher-level cognition, and functioning. This program of research is consistent with several components of the NIMH Strategic Plan and the NIMH Research Domain Criteria project. Results from this research program will lead to information on the similarities and differences in visual processing between SZ and BD, and the underlying neural substrates of visual processing impairment in these conditions. Visual tuning is modifiable and can be reliably assessed in humans and animals, so this information will have implications for treatment development.