汉语双字词启动任务的事件相关电位时空模式

目的:考察汉语双字词启动任务的事件相关电位(ERP)时空模式特性。方法:以词汇重复(例:大豆-大豆)、语义启动(例:高粱-大豆)和语义失配(例:轮船-大豆)三类关系先后显示启动词和靶词,16名被试判断靶词是否与启动词同类而分别按键,同时记录其行为绩效和19通道ERP,应用单因素三水平重复测量方差分析和配对比较,采用统计参数映像(statistical parametric mapping,SPM)呈现ERP结果。结果:反应时间(F(2,26)=77.28,P=0.00)和正确率(F(2,26)=42.91,P=0.00)的重复启动效应均显著,词汇重复组的行为绩效(反应时间601.44±69.39ms,正确率98.7±1.3%)分别优于语义启动组(774.98±87.34ms,88.2±5.9%)和语义失配组(788.75±88.10ms,87.8±4.8%)。虽然后两组行为绩效差异不显著,但其ERP均可见P200、N400和P600成分。SPM提示额顶颞分布的P200效应(200-250ms)与注意调控相关;中央顶分布的N400效应(300-450ms)与语义加工相关;枕颞分布的P600效应(500-1000ms)可能反映语境重构。结论:双字词启动任务的ERP时空模式反映多层次语言加工功能,适用于语言功能评价。

Spatiotemporal Analysis of ERP for Chinese Lexical Priming Effect

Objective: To investigate the priming effect of Chinese words with spatiotemporal pattern of event-related potentials(ERP).Methods: Sixteen subjects joined a lexical decision task.They were asked to judge whether a target word belonged to the same class as the previous word(prime).Three conditions had been set as the word repetition(e.g.soybean-soybean),the semantic priming(e.g.sorghum-soybean) and the semantic mismatching(e.g.ships-soybean).The ERP of 19 channels was recorded and one-way ANOVA of repeated-measurement was carried out for both ERP and behavioral performance.Results: Significant priming effects were for both reaction time: F(2,26)=77.28,P=0.00 and accuracy: F(2,26)=42.91,P=0.00.The performance of the repetition group was significantly better than both the semantic priming one and the semantic mismatching one.No significant difference was found between the latter two groups in behavioral performance.Statistical parametric mapping of ERP showed the P200 effects(200-250ms) within frontoparietal and temporal distribution related attention modulation,the N400 effect(300-450ms) in centroparietal distribution revealing semantic processing and the P600 effect(500-1000ms) in temporal and occipital distribution reflecting the semantic context reconstruction.Conclusion: The lexical decision task involves language processing in multiple levels and it is applicable for the evaluation of language function with spatiotemporal pattern of ERP.