An event-related brain potential study of direct and indirect semantic priming in schizophrenia
An event-related brain potential study of direct and indirect semantic priming in schizophrenia
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DOI：
10.1176/appi.ajp.2007.07050763
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发表时间：
2008-01-01
影响因子：
17.7
通讯作者：
Braff, David L.
中科院分区：
文献类型：
--
作者：
Kiang, Michael;Kutas, Marta;Braff, David L.
目的：有意义的启动刺激后，精神分裂症患者已被假设表现出受损的神经生理激活的相关概念一般，和/或超正常激活弱相关的概念，特别是在语义记忆。前一种异常可能发生在较长的时间间隔，后者在较短的时间间隔后，总理。作者使用N400事件相关脑电位作为语义记忆中概念激活的探针来检验这些假设。方法：在16名精神分裂症患者和16名正常对照者中记录了事件相关电位，他们观看了启动词，每个启动词后面都跟着一个目标，（强）相关词，间接（弱）相关词，无关词，或非词。每种目标类型的相同数量的300和750毫秒后prime.Results：在比较科目，N400振幅是最大的（最负）以下无关的目标，中间后间接相关的目标，和最小后直接相关的目标。相比之下，患者的N400振幅在这些目标类型之间没有差异，反映了患者中直接和间接相关目标的振幅比对照受试者更大;这些发现与原始目标刺激发作无关。在患者中，在较长的dupsy，较大的N400振幅后，直接和间接相关的目标与阳性psychotic symptoms.Conclusions：结果表明hypoactivation的强烈和弱相关的概念后，一个有意义的刺激，无论间隔，精神分裂症。N400指数与妄想的严重程度相关，提示异常语义处理在其发病机制中的作用。
Objective: Following a meaningful prime stimulus, schizophrenia patients have been hypothesized to exhibit impaired neurophysiological activation of related concepts in general, and/or supranormal activation of weakly related concepts in particular, within semantic memory. The former abnormality may occur at longer intervals, and the latter at shorter intervals, after the prime. The authors tested these hypotheses using the N400 event-related brain potential as a probe of activation of concepts in semantic memory.Method: Event-related potentials were recorded in 16 schizophrenia patients and 16 normal comparison subjects who viewed prime words, each followed by a target that was a directly (strongly) related word, indirectly (weakly) related word, unrelated word, or nonword, in a lexical-decision task. Equal numbers of each target type were presented 300 and 750 msec after the prime.Results: In the comparison subjects, N400 amplitude was largest (most negative) following unrelated targets, intermediate after indirectly related targets, and smallest after directly related targets. In contrast, patients' N400 amplitudes did not differ between these target types, reflecting larger amplitudes following both directly and indirectly related targets in patients than in comparison subjects; these findings held regardless of primeto-target stimulus-onset asynchrony. Within patients, at the longer asynchrony, larger N400 amplitudes after directly and indirectly related targets correlated with positive psychotic symptoms.Conclusions: The results suggest hypoactivation of strongly and weakly related concepts following a meaningful stimulus, regardless of interval, in schizophrenia. An N400 index of this hypoactivation correlated with severity of delusions, suggesting a role for abnormal semantic processing in their pathogenesis.