目的:利用fMRI探讨语言任务中动词联想及图片命名任务对大脑语言区的激活模式并分析其临床应用可行性.方法:15例健康志愿者中男8例,女7例,平均年龄(35.7±13.6)岁,均为右利手.应用3T MR仪对每例受试者分别行右手对指运动、动词联想及图片命名任务的BOLD fMRI扫描,采用组块设计方案,利用SPM5软件的总体线性模型(GLM)进行分析并产生激活数据,组分析采用单样本t检验,激活阈值经校正检验,P<0.001(个体)及P<0.01(组分析),激活区坐标经Talairach转换并标定出相应Brodmann(BA)脑区.对每例受试者的两种语言任务分别计算两侧大脑半球激活范围,采用经修改的不包含视皮层激活区的计算公式进行语言优势半球偏侧指数(LI)计算.结果:动词联想任务主要激活双侧Broca′s 区(BA45)、左前额叶背外侧脑区(BA46)、左Wernicke′s区(BA39)、梭状回(BA37)和辅助运动区(BA6),以左侧前额、颞叶语言相关脑区激活为主.图片命名任务主要激活视皮层(BA18)及左BA37、左顶叶(BA7)、基底节区、左背外侧前额叶(BA9)和双侧BA45,以枕、颞叶后部脑区为主.右手对指运动激活左额叶初级运动区(BA4)和BA6.两种语言任务LI计算,符合率为93.3%(14/15),其中左侧优势12例,右侧优势及双侧分布各1例.结论:动词联想主要激活大脑语义加工区,并反映语言区的偏侧优势.图片命名任务可与动词联想共同激活部分语言相关脑区,但对于分析语言偏侧优势有一定缺陷.两种任务的联合使用能够全面了解整体语言功能状况.运动激活作为语言激活信号标准化处理的一个内在评估指标使激活区统计更趋精确和客观.%Objective：To investigate the activation patterns of semantic and lexical retrieval using functional MRl with verb generation(VG)as well as picture naming(PN)paradigms for further clinical application．Methods：15 right handed healthy volunteers[8 male，7 female，(35．7±1 3．6)y]were recruited and informed written consents were provided．All studies were carried out on a 3T MR system(Siemens Trio)．Two conlnlon 1anguage tasks，covertly VG and PN，were used as the stimulation paradigms，based on a block design．Motor task，e．g．right fingers tapping was added as intrinsic references for estimation of individual neuronal activation．Images were processed with SPM5 software，using a general linear model．Group activations were extracted from the 2nd level group analysis with a uniform threshold(P<0．01， FEW)．The coordinates of activations were transferred into Talairach and corresponding Brodmann areas(BA)．A Lateralization Index (LI) was calculated for each subject based on the individual language activation without signals from visual cortex．Results：VG activated mainly the bilateral Broca's area(BA45)，the left dorsolateral prefrontal cortex(BA46)，Wer nicke's area (BA39)，as well as supplementary motor area (BA6) and fusiformgyrus (BA37)，most in the left prefrontal， temporal lobe related to language processing．PN activated visual cortex (BA18) significantly，as well as BA37，BA7，BA45，and BA9 areas，mostly in the left cerebrum．Left primary (BA4) and supplementary motor cortex (BA6) were moderately activated during finger tapping task．The diagnostic accordance rate of LI from PN and VG was 93．3％(14／15)，which in eluded 1 2 cases of left hemisphere lateralization，one right lateralization as well as one bilateral language distribution．Conclusion：VG activations highlighted the main semantic processing area and lateralized by the hemispheric language dominance，which is a reliable method for linguistic functional mapping．PN activated mostly the visual cortex without prominent contribution from hemispheric dominance．A combination of the two tasks can reveal the localization of areas involved in language processing and evaluate language lateralization．The motor activation can be used as an internal statistical indicator for language processing to make the signals more accurate and objective.
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