左侧颞中回在汉语亚词汇加工中神经机制的fMRI研究

目的：利用功能磁共振成像（fMRI）技术探讨左侧颞中回在汉语亚词汇加工过程中的神经机制。方法：对年龄19～25岁的17例健康志愿者在执行汉语同音判断任务时行fMRI扫描。本研究采用了双因素2×2重复测量设计，两个因素分别为汉字的声旁频率（高频、低频）和规则一致性（规则一致、不一致），所用汉字均为低频形声字。行为数据采用SPSS17．0软件包进行方差分析。采用功能神经成像分析软件AFNI对fMRI数据进行处理，并根据组分析结果，做上述4种条件的R01分析。结果：磁共振扫描过程中用DMDX程序记录患者反应，分析显示规则一致性的主效应显著（P〈0．05），而声旁频率的主效应不显著（P〉0．05）。fMRI数据分析的主效应显示，左侧颞中回明显激活，进一步的R01分析结果显示左侧颞中回对频率效应敏感（P〈0．01），而对规则一致性效应不敏感。结论：左侧颞中回在汉语亚词汇加工的语义加工特征中起重要作用。

Functional MRI study of left middle temporal gyrus in sublexical processing of Chinese Character Recognition

Objective：To explore the brain mechanism of the sublexical processing of chinese character in left middle temporal gyrus by using functional magnetic resonance imaging （fMRI）. Methods： In the current study, 17 right-handed Chi nese healthy volunteers （19-25 years old） undertook a homophone judgment task by using fMRI. This study adopted re- peated measurement design with two factors：the frequency of phonetic radicals （high frequency phonetic radicals and low frequency phonetic radicals） and regularity-consistency （regular-consistent and irregular-inconsistent）. All the materials were low frequency characters. ANOVA were used in the analysis of the behavioral data by SPSS 17.0. And fMRI data were analyzed in AFNI software. The ROI analysis of the four levels was processed according to the results of the main effect of ANOVA. Results： The analysis of react time using DMDX program recording showed the main effect of regularity-consisten- cy had statistical significance （P〈0.05）, but the main effect of the phonetic radicals frequency had no statistical significance （P〉0.05）. fMRI demonstrated that the processing in the left middle temporal gyrus was sensitive to frequency effect （P〈 0.01） ,and was not sensitive to regularity-consistency effect in sublexical processing of chinese character recognition. Con- clusion;The left middle temporal gyrus plays an important role in sublexical processing of Chinese character recognition.