Brain Activity and Language Comprehension in Psychosis

描述：(申请人提供)思维障碍是 精神分裂症，是通过异常语言推断出来的。潜在的 导致思维障碍的认知异常尚不清楚。的广泛目标 这项建议是为了了解思维障碍的神经生理学基础。 精神分裂症和精神错乱。我们将测试一个语义模型 精神分裂症患者的过度激活和言语工作记忆功能障碍 与躁狂症中的执行注意力异常形成对比。我们将衡量 语言理解、反应时间和大脑活动通过 事件相关电位，并将这些测量与临床测量相关联 工作记忆表现的症状和神经心理测量。一 可能的功能障碍是语义记忆激活的异常 (超启动)通过上下文不恰当的概念将人群联系在一起 精神分裂症患者的思想。矛盾的是，精神分裂症患者 在快速的词汇决定任务中，表现优于控制组，反应更快 泰晤士报。然而，在较慢的速度下，患者的表现会下降 很明显。这种过度启动和后来的衰退的神经基础 在性能上是未知的。我们测试了一个精神分裂症思维的双因素模型 既有最初的自动兴奋性异常，也有后来的 言语工作中储存的语境的受控使用异常 通过让受试者处理句子、单词对和单词三元组来记忆 语义关联性。刺激将包括同形异义词作为主要探测 联想性错乱。 同形词是具有多种意义的词，并且在不止一个词中占有一席之地 不相关的语义网络。例如，board可能指的是单板或委员会。 精神分裂症患者似乎表现出强烈的语义偏见 伙伴和网络，以便他们倾向于选择主导同形词 意义(板意味着板)，即使面对要求访问的上下文 从属意义(董事会意为委员会)。我们建议研究一下语言 在不同网络强度的情况下进行处理(主导与从属 含义)，同时改变联想强度(强与弱 关联词)，面对强烈的语境偏见和随之而来的弱势 联营公司，并面对随之而来的弱偏见背景 合伙人。这些不同的操作将在FAST(250 毫秒)和慢(1.25秒)的速率，以更加强调语义激活 分别是语言工作记忆系统和语言工作记忆系统。 事件相关电位的使用允许直接测量刺激处理，并提供 关于大脑功能障碍的可能来源的一些信息(当被告知时 来自以前的直接记录)。这些研究可能会有所帮助。 阐明精神分裂症和精神病患者认知功能障碍的本质 狂热。

DESCRIPTION: (provided by applicant) Thought disorder is a cardinal symptom of schizophrenia, and is inferred through abnormal language. The underlying cognitive abnormality that causes thought disorder is unknown. The broad aim of this proposal is to understand the neurophysiological basis of thought disorder in schizophrenia and psychotic mania. We will test a model of semantic over-activation and verbal Working memory dysfunction in schizophrenia, contrasted with an executive attention abnormality in mania. We will measure language comprehension, reaction times, and the activity of the brain via event-related potentials, and correlate these measures with clinical measures of symptoms and neuropsychological measures of working memory performance. One possible dysfunction is an abnormality in semantic memory activation (hyperpriming) whereby associated by contextually inappropriate concepts crowd the mind of schizophrenia patients. Paradoxically, schizophrenia patients outperform controls on speeded lexical decision tasks, with faster reaction times. However, at slower speeds, the performance of patients falls off sharply. The neural substrates of this hyperpriming and of the later drop off in performance are unknown. We test a two-factor model of schizophrenic thought disorder with both an initial automatic excitatory abnormality and a later abnormality in the controlled utilization of context stored in verbal working memory by having subjects process sentences, word pairs, and word triplets for semantic relatedness. The stimuli will include homographs as the primary probe of associative derangement. Homographs are words with multiple meanings, and occupy places in more than one unrelated semantic network. For example, board may mean plank or committee. Schizophrenia patients appear to display a semantic bias towards strong associates and networks such that they tend to select the dominant homograph meaning (board means plank) even in the face of context that mandates accessing the subordinate meaning (board means committee). We propose to examine language processing while varying networks strength (dominant versus subordinate meanings), while varying associative strength (strongly versus weakly associated words), in the face of strongly biasing context followed by weak associates, and in the face of weakly biasing context followed by strong associates. These different manipulations will be presented under fast (250 msec) and slow (1.25 sec) rates, to more heavily stress the semantic activation system and the verbal working memory system respectively. The use of ERPs allows for direct measures of stimulus processing, and provides some information about putative sources of brain dysfunction (when informed from previous direct recordings). These studies have the potential to help clarify the nature of cognitive dysfunction in schizophrenia and in psychotic mania.