PARSING CONTEXTUAL INSENSITIVITY IN SCHIZOPHRENIA

精神分裂症思维障碍的一个显著特征是上下文不敏感。我们建议使用语义启动范式来检验情境抑制受损而非情境促进是精神分裂症情境不敏感的主要机制的假设。在我们的这个技术版本中，受试者听包含歧义词（例如，笔）的句子启动词，并看到与语义上的主导（例如，纸）或从属（例如，猪）意义相关的词汇决策反应（例如，词/非词判断）。实验1a和1b测试了语义约束和加工时间对精神分裂症患者（n=65）、正常对照（n=40）和非精神分裂症对照（n=40）的语境促进和抑制的影响。在实验1a中，句子语境将是中性的，中度和强烈地偏向于歧义词的从属意义。实验1b将与实验1a相同，除了视觉目标将在句子启动的声音偏移后1000毫秒呈现（即1000毫秒刺激启动的异步），以提供额外的时间来处理上下文。预计精神分裂症患者会表现出(1)在中度从属偏见语境中，对与语境无关的主导意义的语境抑制受损；(2)在中度和强烈从属偏见语境中，对从属意义的语境促进完整；(3)在语境强度增加的同时，语境抑制适度增加；(4)给予额外的时间来处理语境，语境抑制和促进会增加。此外，语言任务的表现将通过独立的思维障碍（即，每个参与者的思维障碍指数（TDI）总分和TDI的异常言语化子得分）和认知抑制（例如，在Stroop干扰任务、消极启动任务和反扫视任务中的表现）的测量来检验。这项工作的结果将为精神分裂症中上下文不敏感的认知机制提供更清晰的理解。因此，他们将为精神分裂症的语境处理和抑制性功能障碍理论提供信息，这些理论适用于广泛的神经认知任务。

A hallmark characteristic of thought disorder in schizophrenia is contextual insensitivity. We propose to test the hypothesis that impaired contextual inhibition, but not contextual facilitation, is the primary mechanism of contextual insensitivity in schizophrenia using a semantic priming paradigm. In our version of this technique, subjects listen to sentence primes containing ambiguous words (e.g., pen), and see targets presented for a lexical decision response (i.e., word/nonword judgment) that are semantically related to dominant (e.g., paper) or subordinate (e.g., pig) meanings. Experiments 1a and 1b test the effects of semantic constraint and processing time on contextual facilitation and inhibition in schizophrenic patients (n=65), normal controls (n=40), and non- schizophrenic psychiatric controls (n=40). In Experiment 1a, sentence contexts will be neutral, and moderately and strongly biased towards the subordinate meaning of an ambiguous words. Visual targets will immediately follow the acoustic offset of the sentence prime (i.e., 0 ms stimulus onset asynchrony) Experiment 1b will be identical to Experiment 1a except that the visual target will be presented 1000 ms following the acoustic offset of the sentence prime (i.e., 1000 ms stimulus onset asynchrony) to provide additional time to process the context. Schizophrenic patients are predicted to show (1) impaired contextual inhibition for contextually irrelevant dominant meanings in moderate subordinate-biased contexts, (2) intact contextual facilitation of subordinate meanings for moderate and strong subordinate-biased contexts, (3) appropriate increases in contextual inhibition accompanying increases in contextual strength, and (4) increased contextual inhibition and facilitation given additional time to process the context. In addition, performance on the language task will be examined with respect to independent measures of thought disorder (i.e., each participant's total Thought Disorder Index (TDI) score and Deviant Verbalization subscore of the TDI) and cognitive inhibition (e.g., performance on the Stroop interference task, the negative priming task, and the antisaccade task). The results of this work will provide a clearer understanding of the cognitive mechanisms underlying contextual insensitivity in schizophrenia. Thus they will inform theories of contextual processing and inhibitory dysfunction in schizophrenia that are applicable to a wide array of neurocognitive tasks.