近日,，國際著名雜志PLoS One在線刊登了中科院研究人員的最新研究成果“Semantic Processing Disturbance in Patients with Schizophrenia: A Meta-Analysis of the N400 Component,。”精神分裂癥患者的語言模式異于常人。在不同的疾病階段,，患者的語言表現(xiàn)為結(jié)構(gòu)松散、上下文缺乏連貫,、語言貧乏等等,。研究者發(fā)現(xiàn)患者存在語義加工的缺損。然而，缺損究竟存在于語義加工的哪個(gè)階段依然是一個(gè)懸而未決的問題,。
理論上語義加工可以分成兩個(gè)階段：早期自動(dòng)擴(kuò)散的語義激活和晚期的情境加工,。通過一項(xiàng)關(guān)于N400成分的元分析，中國科學(xué)院心理健康重點(diǎn)實(shí)驗(yàn)室神經(jīng)心理學(xué)與應(yīng)用認(rèn)知神經(jīng)科學(xué)（NACN）課題組的陳楚僑研究員和王葵博士試圖回答這個(gè)問題,。
對(duì)比患者和健康控制組的N400效應(yīng),，靶向早期自動(dòng)擴(kuò)散的語義激活過程的研究產(chǎn)生了一個(gè)中等程度的效應(yīng)值(Cohen’s d = 0.41)，靶向晚期情境加工過程的研究產(chǎn)生了一個(gè)小效應(yīng)值(Cohen’s d = 0.36),。此外,，分析靶向晚期情境加工過程的研究，一致/相關(guān)條件下的N400波幅產(chǎn)生了一個(gè)中等程度的效應(yīng)值(Cohen’s d = 0.52),，且 N400差異波的潛伏期產(chǎn)生了一個(gè)大效應(yīng)值(Cohen’s d = 0.82),。基于這些發(fā)現(xiàn),，陳楚僑研究員和王葵博士認(rèn)為,，精神分裂癥患者早期自動(dòng)擴(kuò)散的語義激活過程和晚期的情境加工都存在缺損。在早期自動(dòng)擴(kuò)散的語義激活階段患者對(duì)于相鄰的語義節(jié)點(diǎn)的加工和對(duì)不相鄰語義節(jié)點(diǎn)的加工過程類似,。此外,，患者加工語義情境相關(guān)內(nèi)容效率低。這些發(fā)現(xiàn)對(duì)于考察整個(gè)精神分裂癥譜系的語義加工過程非常重要,。整個(gè)精神分裂癥譜系不僅包括患者,，還包括那些近期有高危的個(gè)體。
這項(xiàng)研究得到中國科學(xué)院“百人計(jì)劃”項(xiàng)目,、中科院知識(shí)創(chuàng)新工程和國家自然科學(xué)基金委的支持,。（生物谷Bioon.com）
doi:10.1371/journal.pone.0025435
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Semantic Processing Disturbance in Patients with Schizophrenia: A Meta-Analysis of the N400 Component
Kui Wang1, Eric F. C. Cheung2, Qi-yong Gong3, Raymond C. K. Chan1*
Background Theoretically semantic processing can be separated into early automatic semantic activation and late contextualization. Semantic processing deficits have been suggested in patients with schizophrenia, however it is not clear which stage of semantic processing is impaired. We attempted to clarify this issue by conducting a meta-analysis of the N400 component. Methods Twenty-one studies met the inclusion criteria for the meta-analysis procedure. The Comprehensive Meta-Analysis software package was used to compute pooled effect sizes and homogeneity. Results Studies favoring early automatic activation produced a significant effect size of −0.41 for the N400 effect. Studies favoring late contextualization generated a significant effect size of −0.36 for the N400 effect, a significant effect size of −0.52 for N400 for congruent/related target words, and a significant effect size of 0.82 for the N400 peak latency. Conclusion These findings suggest the automatic spreading activation process in patients with schizophrenia is very similar for closely related concepts and weakly or remotely related concepts, while late contextualization may be associated with impairments in processing semantically congruent context accompanied by slow processing speed.
