PARSING CONTEXTUAL INSENSITIVITY IN SCHIZOPHRENIA

精神分裂症思维障碍的一个标志性特征是对上下文不敏感。 我们建议使用语义启动范式来检验这一假设，即受损的上下文抑制，而不是上下文促进，是精神分裂症患者上下文不敏感的主要机制。 在我们的这个技术版本中，受试者听包含歧义词的句子启动（例如，笔），并查看为词汇决策响应呈现的目标（即，词/非词判断），其在语义上与主导词相关（例如，纸）或从属（例如，猪的意思。实验1a和1b考察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）和非精神分裂症精神病对照组（n=40）的语境易化和抑制的影响。 在实验1a中，句子语境将是中性的，并适度和强烈地偏向于一个歧义词的从属意义。视觉目标将立即跟随句子主音的声学偏移（即，0 ms刺激起始时间（0 ms）实验1b将与实验1a相同，除了视觉目标将在句子启动的声学偏移之后1000 ms呈现（即，1000 ms刺激起始时间）以提供额外的时间来处理上下文。精神分裂症患者在中度从属偏向的语境中，对与语境无关的主导意义的语境抑制受损，在中度和强烈从属偏向的语境中，对从属意义的语境促进作用完整，在语境强度增加的同时，语境抑制适当增加，以及（4）给予额外的时间来处理上下文，增加了上下文抑制和促进。 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）评分和TDI的异常言语化分项评分）和认知抑制（例如，在Stroop干扰任务、负启动任务和反跳跃任务上的表现）。这项工作的结果将提供一个更清晰的理解认知机制的背景不敏感精神分裂症。 因此，他们将告知精神分裂症的上下文处理和抑制功能障碍的理论，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.