An EEG Study of Neural Dynamics in Schizophrenia

描述（由申请人提供）：该提案描述了一个B/START项目，该项目将使用脑电图（EEG）中的神经同步测量来检查精神分裂症神经回路的功能完整性。精神分裂症被认为是一种认知整合的失败，神经回路的异常被认为是这种疾病的基础。我们假设伽马波段脑电图振荡的异常反映了精神分裂症患者神经回路同步性的障碍，并且与核心认知障碍直接相关。（请注意，PI是一名新独立的精神分裂症研究人员，两年前完成了该领域的博士后培训，因此处于B/START资助的理想阶段。）先前我们报道了精神分裂症患者视觉格式塔模式引发的伽马波段振荡的两个主要异常：1)刺激诱发振荡（SEO）缺失，2)反应锁定振荡（RLO）发生在比对照组更低的频段。在精神分裂症患者中，RLO与视觉幻觉、思维障碍和混乱正相关。我们假设精神分裂症患者缺乏SEO是由于在早期视觉处理阶段缺乏自上而下的同步注意增强，这与精神分裂症的注意缺陷特征是一致的。鉴于RLO似乎产生于视觉皮层，但与反应时间有关，并且与精神分裂症的核心知觉和认知功能障碍有关，我们假设RLO反映了一种基于同步的神经机制，该机制与意识知觉的产生密切相关，并且对精神分裂症的原发性神经回路异常敏感。因此，更好地了解SEO和RLO的功能意义可能有助于对精神分裂症认知功能障碍的神经基质有新的认识。为了验证这些假设，我们将检查慢性精神分裂症患者和匹配的健康对照者在执行视觉感知任务时的神经同步性，这些任务可能涉及通过神经元同步进行特征整合。我们的具体目的是：1)测试精神分裂症患者的SEO缺失是否与刺激无关，2)反映了同步性注意力增强的缺乏。3)测试RLO反映了一种涉及有意识客体感知的特征绑定机制。4)证实我们之前关于精神分裂症异常和RLO症状相关性的发现。为了治疗并最终预防神经精神疾病，我们必须了解精神和大脑是如何相互关联的。该项目旨在通过研究健康人以及精神分裂症患者的脑波同步如何与感知和思考相关来进一步实现这一目标。

DESCRIPTION (provided by applicant): This proposal describes a B/START project that will use measures of neural synchrony in the electroencephalogram (EEG) to examine the functional integrity of neural circuitry in schizophrenia. Schizophrenia has been conceptualized as a failure of cognitive integration, and abnormalities in neural circuitry have been proposed as a basis for this disorder. We hypothesize that abnormalities in gamma-band EEG oscillations reflect impairments in the synchronization of neural circuits in schizophrenia, and are directly related to core cognitive impairments. (Please note that the PI is a newly independent investigator in schizophrenia research, having finished his postdoctoral training in this field 2 years ago, and thus is at an ideal stage in his career for a B/START grant.) Previously we reported two major abnormalities in the gamma-band oscillations elicited by visual Gestalt patterns in schizophrenics: 1) the stimulus-evoked oscillation (SEO) was absent, and 2) the response-locked oscillation (RLO) occurred in a lower frequency band for patients than controls. In schizophrenics, the RLO was positively correlated with visual hallucinations, thought disorder, and disorganization. We hypothesize that the absence of the SEO in schizophrenics is due to a lack of top-down attentional enhancement of synchrony at this stage of early visual processing, which would be consistent with the attentional deficits that characterize schizophrenia. Given that the RLO appears to be generated in visual cortex but is coupled to reaction time, and is related to core perceptual and cognitive dysfunctions in schizophrenia, we hypothesize that the RLO reflects a synchrony-based neural mechanism that is closely involved in the generation of conscious perceptions, and is sensitive to primary neural circuit abnormalities in schizophrenia. Thus, a better understanding of the functional significance of the SEO and RLO may lead to new insights into the neural substrates of cognitive dysfunction of schizophrenia. To test these hypotheses, we will examine neural synchrony in chronic schizophrenia patients and matched healthy controls while they perform visual perception tasks which presumably involve feature integration via neuronal synchronization. Our specific aims are to: 1) Test whether the absence of the SEO in schizophrenics is stimulus-independent, and 2) reflects a lack of attentional enhancement of synchrony. 3) Test that the RLO reflects a feature-binding mechanism involved in conscious object perception. 4) Confirm our previous findings of schizophrenic abnormalities and symptom correlations in the RLO. To treat and ultimately prevent neuropsychiatric disorders, we must understand how the mind and brain are interrelated. This project seeks to further this goal by studying how brainwave synchronization is related to perception and thinking in people who are healthy, and in people who have schizophrenia.