PARSING CONTEXTUAL INSENSITIVITY IN SCHIZOPHRENIA

精神分裂症患者思维障碍的一个特点是对背景不敏感。我们建议使用语义启动范式来检验这一假设，即受损的语境抑制，而不是语境促进，是精神分裂症中语境不敏感的主要机制。在这项技术的我们的版本中，受试者听含有歧义单词(例如笔)的句子质数，并看到为词汇决定反应(即单词/非单词判断)呈现的目标，这些目标在语义上与主要意义(例如纸张)或从属意义(例如猪)相关。实验1a和1b测试了语义限制和加工时间对精神分裂症患者(n=65)、正常对照组(n=40)和非精神分裂症对照组(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，并适度和强烈地偏向于歧义词的从属意义。视觉目标将紧跟在句子质数的声学偏移之后(即，0ms刺激开始异步)实验1b将与实验1a相同，除了视觉目标将在句子质数的声学偏移之后呈现1000ms(即，刺激开始异步1000ms)，以提供额外的时间来处理上下文。据预测，精神分裂症患者在中度从属偏向语境中表现出(1)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向语境中对从属意义的完整语境促进，(3)伴随语境强度的增加而适当增加语境抑制，以及(4)在给予更多的时间来处理语境时，语境抑制和促进作用增加。此外，语言任务的表现将根据思维障碍的独立测量(即，每个参与者的总思维障碍指数(TDI)分数和TDI的偏离言语分值)和认知抑制(例如，在Stroop干扰任务、负面启动任务和反扫视任务上的表现)进行检查。这项工作的结果将为更清楚地理解精神分裂症中潜在的语境不敏感的认知机制提供帮助。因此，他们将提供有关精神分裂症的背景加工和抑制功能障碍的理论，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.