An EEG Study of Neural Dynamics in Schizophrenia

描述(由申请人提供)：本提案描述了一个B/START项目，该项目将使用脑电(EEG)中神经同步性的测量来检查精神分裂症患者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，伽马频段脑电振荡的异常反映了精神分裂症患者神经回路同步的损害，并与核心认知损害直接相关。(请注意，私人助理是精神分裂症研究的一名新的独立研究员，两年前完成了这一领域的博士后培训，因此正处于其职业生涯中获得B/START补助金的理想阶段。)在此之前，我们报道了精神分裂症患者视觉格式塔图形诱发的伽玛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、思维障碍和组织紊乱呈正相关。我们假设，精神分裂症患者SEO的缺失是由于在早期视觉加工的这个阶段缺乏自上而下的注意增强同步性，这与精神分裂症的注意缺陷是一致的。鉴于RLO似乎是在视皮层产生的，但与反应时间有关，并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，并对精神分裂症的初级神经回路异常敏感。因此，更好地理解SEO和RLO的功能意义可能会导致对精神分裂症认知功能障碍的神经基础的新见解。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组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。我们的具体目标是：1)测试精神分裂症患者SEO的缺失是否与刺激无关，以及2)反映缺乏注意增强的同步性。3)测试RLO是否反映了一种涉及有意识物体知觉的特征绑定机制。4)证实了我们以前在RLO中发现的精神分裂症异常和症状相关性。为了治疗并最终预防神经精神障碍，我们必须了解大脑和大脑是如何相互联系的。这个项目试图通过研究脑波同步如何与健康人和精神分裂症患者的知觉和思维有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.