Auditory-verbal functional studies of schizophrenia

描述（由申请人提供）：本提案将使用功能性磁共振成像（fMRI）来评估早期听觉加工、言语语义加工及其与首发（FE）、慢性精神分裂症（CSZ）和匹配对照（CN）阳性症状的关系。这些研究旨在了解脑功能障碍和症状之间的联系，从而促进预防措施和治疗的发现。颞上回在听觉、言语感知和语言加工中起着重要作用。在精神分裂症患者（SZ）的MRI研究中，该区域一直显示体积减少。这些体积减少与幻听、思维障碍和听觉事件相关电位（ERP）异常有关。左STG异常也一致显示在活跃幻觉或SZ的听觉-言语处理的功能成像研究中。使用错配负性刺激（MMN）发现慢性SZ患者STG的异常fMRI活动与ERP范式相似。最近的发现已经证明了正常个体的语言侧化基础的结构和功能证据。除了MMN任务外，我们将在快速声学处理任务（RAP）中使用这些最新发现，作为拟议研究SZ早期听觉处理的基础。侧颞区（中、下）和颞顶叶区被认为在语义加工中起作用。在使用语言的精神分裂症的功能成像和ERP研究中，这些区域也显示出异常。在许多研究中，语义启动已被证明（尽管不一致）在SZ中是异常的。最近的一项行为研究使用了语义网络属性不同的单词。SZ被试在线索记忆方面的表现下降与语义网络连接异常有关，而与网络规模无关。SZ和CN被试将进行听觉/言语语义启动的fMRI研究。本研究将探讨与语义关联之间扩散激活相关的大脑活动。单词的连接程度不同，因此在它们的关联词之间传播激活的程度也不同。最近完成的一项针对CN受试者的初步研究使用了语义启动任务（SP），结果发现，正如预测的那样，颞叶区域的不同大脑活动模式与单词对的不同语义特性（连通性和相关性）相关。

DESCRIPTION (provided by applicant): This proposal will use functional magnetic resonance imaging (fMRI) to assess early auditory processing, verbal semantic processing, and their association with positive symptoms in first episode (FE), chronic schizophrenic (CSZ), and matched control subjects (CN). These studies are aimed at understanding the link between brain dysfunction and symptoms, thus facilitating the discovery of preventative measures and treatments. The superior temporal gyrus (STG) plays a major role in auditory speech perception and language processing. This region is consistently reported to show volume reductions in MRI studies of schizophrenic subjects (SZ). These volume reductions have been linked to auditory hallucinations, thought disorder, and auditory event-related potential (ERP) abnormalities. Left STG abnormalities are also consistently shown in functional imaging studies of active hallucination or of auditory-verbal processing in SZ. Abnormal fMRI activity in the STG in chronic SZ was found using mismatch negativity (MMN) stimuli that were similar to those used in an ERP paradigm. Recent discoveries have documented structural and functional evidence for the basis of language lateralization in normal individuals. We will use these recent discoveries, in a rapid acoustic processing task (RAP), in addition to the MMN task, as a basis for proposed studies examining early auditory processing in SZ. Lateral temporal (middle, inferior) and temporal-parietal regions are thought to play a role in semantic processing. These regions have also shown abnormalities in functional imaging and ERP studies of schizophrenia that use language. Semantic priming has been shown (although not consistently) in a number of studies to be abnormal in SZ. A recent behavioral study used words that differed in terms of the properties of their semantic networks. The reduced performance of SZ subjects on the cued recall of words was attributed to the effects of abnormal connectivity in the semantic network but not network size. SZ and CN subjects will be tested in an fMRI study of auditory/verbal semantic priming. This study will examine the brain activity related to the spreading activation between semantic associates. Words will vary in the degree of connectivity, and hence the degree of spreading activation between their associates. A recently completed preliminary study of CN subjects used this semantic priming task (SP) and found that as predicted, different patterns of brain activity in temporal lobe regions were associated with different semantic properties (connectivity and relatedness) of the word pairs.