抑郁症患者情绪图片刺激早期低频脑磁图研究

目的：探讨抑郁症患者给予视觉情绪图片刺激早期0～100ms、100～200ms、200～300ms3个时段8～30Hz的神经磁场激活特征。方法：8例抑郁症患者及12例健康右利手对照者,在给予国际情绪图片库（IAPS）正性、中性、负性情绪图片刺激同时记录脑磁图信号,使用SPM8b软件进行数据分析：设两样本t检验P〈0.01（未校正）和K值≥10个体素范围为差异有统计学意义。结果：与对照组相比,抑郁组在正性情绪图片刺激下,100～200ms内的左侧额下回,右侧的终板旁回、额内侧回、海马回激活增强。在中性情绪图片刺激下,抑郁组在0～100ms的右侧豆状核、岛叶、额上回,左内侧额叶,100～200ms内的右侧岛叶、豆状核壳核及屏状核,左侧额下回、额上回、颞上回,200～300ms内的右侧岛叶、豆状核、尾状核体激活增强。负性情绪图片刺激下抑郁组在0～100ms内的右侧颞上回、岛叶、尾状核头部、额中下回激活增强,100～200ms内的右侧额中回、尾状核体,200～300ms内右额下回激活增强。此外还比较一致的发现抑郁组在楔前叶、后扣带回等顶叶脑区激活降低。结论：抑郁个体起注意调节功能的顶叶脑区如楔前叶功能不足,对视觉皮质向前部脑区情绪信息颞叶底部传递通路抑制不足,腹侧前额皮质、岛叶过度的激活,可能是抑郁症的一个发病基础。     

首发抑郁症患者局部脑葡萄糖代谢的PET初步研究

目的　探讨首发抑郁症脑葡萄糖代谢特点及与临床症状、神经心理的相关性。方法　对14例首发抑郁症患者与 11例健康对照者进行正电子发射断层扫描 (positionemissiontomography ,PET)。抑郁症患者行汉密尔顿抑郁量表 (HAMD17)、Montgomery Asberg抑郁量表 (MADS)、汉密尔顿焦虑量表 (HAMA)、临床疗效总评量表 (CGI)、中国修订版韦克斯勒成人智力量表 (WAIS RC)、中国修订版韦克斯勒记忆量表 (WMS RC)、威斯康星卡片分类测验 (WCST)评定。结果　 (1)感兴趣区 (ROI)分析显示抑郁症组右侧额上回、右侧扣带回的rCMRglc显著低于健康对照组 (P <0 0 5 ) ;抑郁症组右侧额上回rCMRglc降低甚于左侧额上回rCMRglc降低 (P <0 0 5 )。 (2 )抑郁症组左侧、右侧rCMRglc与其MADS评分值呈负相关 (分别为P <0 0 5、P <0 0 1) ;右侧额上回、双侧额中回、双侧扣带回、双侧颞叶rCMRglc与SI评分值呈负相关 (除右颞叶P <0 0 1,余区域P <0 0 5 ) ;左侧额下回rCMRglc与其WMS评分值呈正相关P <0 0 5 )。 (3)抑郁症组右侧丘脑rCMRglc与其 1→ 10 0数数值呈正相关 (P <0 0 5 ) ;右侧额中回rCMRglc与其图片值呈负相关 (P <0 0 5 ) ;右侧岛叶rCMRglc与其再认值呈正相关 (P <0 0 5 ) ;左侧颞叶、左侧枕叶rCMRglc与其理解记忆     

不同发作类型内侧颞叶癫灰质改变的结构性磁共振成像研究

目的探讨不同发作类型内侧颞叶癫患者灰质体积变化及其与病程的相关性。方法共40例内侧颞叶癫患者[部分性发作20例(m TLE-PS组)和继发性全面性发作20例(m TLE-s GS组)]以及20例性别、年龄相匹配的正常对照者行头部T1-三维磁化准备快速梯度回波扫描,采用基于体素的形态学分析进行灰质结构分割,选取双侧额叶和丘脑作为兴趣区,比较3组受试者各脑区灰质体积,采用Spearman秩相关分析探讨内侧颞叶癫患者各脑区灰质体积与病程的相关性。结果 3组受试者双侧额上回、右侧额中回、右侧额内侧回、右侧角回、右侧颞中回、右侧海马、双侧丘脑和双侧小脑半球灰质体积差异有统计学意义(均P0.01,FWE校正),与正常对照组相比,m TLE-PS组双侧额上回、小脑半球和右侧颞中回、海马、丘脑灰质体积减少(均P0.01,FWE校正),m TLE-s GS组双侧额上回、丘脑、小脑半球和右侧角回、颞中回、海马灰质体积减少(均P0.01,FWE校正);与m TLE-PS组相比,m TLE-s GS组双侧额上回、丘脑和右侧额内侧回、直回灰质体积减少(均P0.01,FWE校正)。m TLE-s GS组患者左侧额上回(rs=-0.611,P=0.004)和右侧额中回(rs=-0.562,P=0.010)与病程呈负相关关系。结论不同发作类型内侧颞叶癫患者均存在双侧额叶、丘脑、小脑半球和右侧颞叶、海马灰质损伤,但损伤脑区有所不同,继发性全面性发作患者以双侧额叶和丘脑灰质体积减少为主,提示丘脑-皮质环路是内侧颞叶癫继发性全面性发作的重要结构基础。     

抑郁症患者局部脑葡萄糖代谢的SPM分析

目的探讨首发抑郁症患者的局部脑葡萄糖代谢特点。方法对14例首发并且符合DSM-Ⅳ的抑郁症患者进行汉密尔顿抑郁量表(HAMD17)、Montgomery-Asberg抑郁量表(MADS)、汉密尔顿焦虑量表(HAMA)的评估及18F-FDGPET检查;对11例年龄、性别、文化程度均相匹配的健康对照者进行18F-FDGPET检查。18F-FDGPET显像后,用统计参数地图(SPM,P值设为0.001)方法分析抑郁症组和健康对照组的局部脑葡萄糖代谢分布差别。结果SPM分析显示双侧额上回、右侧额中回、右侧额叶内侧,右侧脑岛葡萄糖代谢率显著低于对照组(P<0.001);左侧丘脑,左侧前扣带回,双侧小脑前叶山顶、右侧小脑后叶山坡,左侧枕中回,左侧颞中、下回葡萄糖代谢率显著高于对照组(P<0.001)。结论首发抑郁症患者存在皮质-丘脑-边缘回路代谢异常;小脑的代谢异常是一个值得关注的区域;从神经影像学角度为抑郁症的早期诊断提供参考依据。     

抑郁认知易感者在负性情绪信息加工中的脑功能连接特征

目的 探讨抑郁认知易感者和抑郁症患者在负性情绪信息加工过程中杏仁核与不同脑区之问是否具有特殊的脑功能连接方式.方法 使用认知方式问卷筛查得到抑郁认知易感者(易感组,26例)与非易感者(对照组,31名),选取同期临床抑郁症患者(抑郁症组,29例),分别完成情绪面孔匹配任务,同步进行功能磁共振扫描;采用功能连接方法比较各组杏仁核与不同脑区之间的功能连接差异.结果 易感组的杏仁核与右侧额中回之间的功能连接比对照组弱[蒙特利尔神经研究所(MNI):26,40,-12;t =3.88,P＜0.001,k=10],抑郁症组杏仁核与左侧额下回之间的功能连接比对照组弱(MNI:-46,24,-12;t =4.20,P＜0.001,k=16).结论 在面对负性刺激时,抑郁认知易感者和抑郁症患者杏仁核与前额叶之间的功能连接降低.     

矿难后急性重性创伤后应激障碍症状激发和创伤有关短期记忆提取的功能性磁共振成像研究

目的 探讨急性重性创伤后应激障碍(post traumatic stress disorder,PTSD)患者的脑功能及执行记忆功能时的脑反应.方法 采用功能磁共振成像技术,对经历矿难的10例急性重性PTSD患者(PTSD组)和7例非PTSD对照(非PTSD组)执行症状激发任务,并首次采用1项创伤有关的短期记忆提取任务进行记忆功能的测定.结果 症状激发试验中,PTSD组负性图片相比中性图片,左侧后扣带回、双侧尾状核和右侧丘脑等脑区激活增强,右侧扣带回和双侧额中回激活下降;PTSD组相比非PTSD组,右侧前扣带回、左侧额下回、双侧额中回及双侧颞中回等脑区激活下降,左侧海马旁回激活增高.短期记忆提取任务中,PTSD组负性图片相比中性图片,右侧后扣带回和双侧海马存在明显激活;PTSD组相比非PTSD组,右侧额下回、右侧额中回、左侧枕中回等脑区激活下降.记忆提取任务相比症状激发任务,PTSD组右侧海马旁回激活下降.结论 急性重性PTSD患者在急性期已存在部分脑区激活的下降以及记忆功能的减退.     

抑郁症患者情绪图片反应特征及杏仁核反应模式的研究

目的 探讨抑郁症患者对情感刺激的行为学反应模式及其相关的杏仁核时程反应过程.方法 12例首次发病、未经治疗的抑郁症患者(抑郁症组)和13名健康个体(健康对照组)对观看正性、中性和负性情绪图片的愉悦度等评分;并在被动注视任务下行功能磁共振成像,采用感兴趣区分析方法,比较两组杏仁核在不同情绪图片任务组块间的血氧水平依赖(BOLD)信号时间反应特征.结果 (1)抑郁症组情绪图片愉悦度评分[正性:(6.6 ±0.2)分;中性:(4.7 ±0.1)分]低于健康对照组[分别为(7.7 ±0.2)分和(5.1 ±0.1)分],负性情绪图片评分[(3.4 ±0.3)分]高于健康对照组[(2.2 ±0.2)分;P<0.01].(2)对正性情绪图片任务,两组间右侧杏仁核存在"组×时间"交互作用(P=0.002);抑郁症组杏仁核BOLD信号变化率为(0.02±0.09)%,激活时间后移至Block 2.对负性情绪图片任务,两组间左侧杏仁核有"组×时间"交互作用(P=0.008),右侧杏仁核存在组主效应(P=0.007)和时间主效应(P=0.016),抑郁症组BOLD信号变化率低于(-0.06 ±0.14)%.结论 杏仁核是抑郁症患者丧失愉悦体验和情绪低落的神经基础之一.     

~(18)F-FDG PET显像观察特发性快眼动睡眠期行为障碍患者脑葡萄糖代谢特点的研究

目的探讨~(18)F-FDG PET显像观察特发性快眼动睡眠期行为障碍(iRBD)患者脑葡萄糖代谢改变和iRBD脑葡萄糖代谢改变与病程间的相关性。方法纳入多导睡眠监测(PSG)确诊的iRBD患者20例(iRBD组)和年龄、性别匹配的健康对照者19例(对照组)。两组均行~(18)F-FDG PET脑显像。基于自动解剖标记模板将大脑划分为90个左右对称的脑区,计算各脑区葡萄糖代谢半定量值。对iRBD组和对照组各脑区葡萄糖代谢半定量值进行独立样本t检验;并对iRBD组脑葡萄糖代谢改变与病程行Pearson相关分析。结果 (1)与对照组比较,iRBD组的双侧背外侧额上回、双侧眶部额上回、双侧眶部额中回、双侧海马、双侧海马旁回、双侧杏仁核、左侧眶部额下回、左侧岛叶、左侧内侧与旁扣带脑回、左侧中央旁小叶、左侧苍白球的葡萄糖代谢半定量值均增高(P0.05);双侧距状裂周围皮质、双侧楔叶、双侧舌回、双侧枕上回、双侧枕中回、双侧枕下回、双侧角回、双侧颞上回、双侧颞中回、右侧颞横回的葡萄糖代谢半定量值均降低(P0.05)。Pearson相关分析结果,iRBD组双侧杏仁核、双侧颞上回、右侧楔叶、右侧枕上回、右侧颞横回、左侧海马、左侧颞中回的葡萄糖代谢半定量值与病程呈正相关(P0.05);而双侧眶部额上回、双侧眶部额中回、左侧中央旁小叶、左侧眶部额下回、左侧内侧和旁扣带回、右侧背外侧额上回、右侧海马旁回的葡萄糖代谢半定量值与病程呈负相关(P0.05)。结论 iRBD患者脑内存在疾病相关的葡萄糖代谢水平改变,有助于客观评估iRBD病情的变化。     

首次发病且未用药的成年早发和晚发抑郁症患者脑功能连接差异研究

目的比较成年早发抑郁症(EOD)和成年晚发抑郁症(LOD)患者默认网络(DMN)内部功能连接的差异,探究不同发病年龄的抑郁症患者是否有不同的发病机制。方法选取在昆明医科大学第一附属医院精神科门诊或住院的EOD患者(n=58)和LOD患者(n=62)为研究对象,同期招募年轻健康对照组(n=60)和年老健康对照组(n=52)。对受试者进行静息态功能磁共振扫描,选择左侧楔前叶为种子点,计算该种子点与全脑的功能连接,并比较各组间该种子点的功能连接差异。结果四组之间功能连接具有差异的脑区涉及双侧额叶、颞叶、基底节、枕叶、顶叶及小脑等脑区。EOD组左侧楔前叶与左侧小脑Crus1区、左侧小脑IX区、左侧颞中回、右侧楔前叶、右侧前扣带回、右侧额中回、右侧角回、右侧脑岛、右侧内侧额上回、右侧颞中回的功能连接均高于年轻健康对照组(Z=3. 752 4～5. 867 8,P均0. 05);而左侧楔前叶与左侧额中回、左侧中央旁小叶、右侧缘上回、右侧额上回、右侧颞下回、右侧中央后回、右侧中央前回、右侧枕上回的功能连接均低于年轻健康对照组(Z=-5. 007 6～-3. 797 7,P均0. 05)。LOD组左侧楔前叶与左侧小脑Crus2区、左侧尾状核、左侧颞下回、左侧小脑Crus1区、左侧角回、左侧额中回、右侧额中回、右侧角回、右侧眶额部额中回的功能连接均高于年老健康对照组(Z=4. 122 8～6. 579 4,P均0. 05);与左侧海马旁回、左侧额上回、右侧枕中回、右侧中央前回、右侧内侧额上回、右侧锯状回、右侧颞下回、右侧中央旁小叶、右侧梭状回、右侧后扣带回的功能连接均低于年老健康对照组(Z=-5. 884 0～-3. 617 2,P均0. 05)。EOD组左侧楔前叶与左侧锯状回、左侧小脑IV-VI区、左侧小脑Crus2区的功能连接比LOD组高(Z=4. 087 7、3. 937 4、3. 672 1,P均0. 05);EOD组左侧楔前叶与右侧额中回、右侧眶额部额下回、右侧额上回的功能连接比LOD组低(Z=-4. 274 8、-3. 956 8、-4. 724 3、-3. 663 2,P均0. 05)。结论 DMN内部功能连接增高及额顶网络功能连接降低可能与EOD的发病机制相关,而DMN前部功能连接增高和后部功能连接降低可能与LOD的发病机制相关,不同发病年龄的成年抑郁症患者可能有不同的发病机制。     

重性抑郁症基于低频振幅的静息态功能磁共振成像研究

目的观察重性抑郁症患者静息态fMRI(rs-fMRI)特点,并探讨其可能发病机制。方法采用基于低频振幅(ALFF)的rs-f MRI对24例重性抑郁症患者和性别、年龄、受教育程度匹配的26例正常对照者进行比较,Spearman秩相关分析探讨各脑区mALFF值与汉密尔顿抑郁量表17项(HAMD-17)评分的相关性。结果与正常对照者相比,重性抑郁症患者双侧背外侧前额叶皮质、右侧眶部额上回、右侧颞下回、左侧岛盖部额下回、左侧内侧额上回、左侧直回mALFF值升高(均P0.05,AlphaSim校正),双侧补充运动区、右侧后扣带回、右侧楔前叶、左侧舌回mALFF值降低(均P0.05,AlphaSim校正)。Spearman秩相关分析显示,重性抑郁症患者各脑区mALFF值与HAMD-17评分无关联性(均P0.05)。结论重性抑郁症患者静息态下神经功能损害主要集中于脑默认网络和边缘系统等多个脑区,提示其可能存在特征性神经功能改变基础。     

首发精神分裂症患者的功能磁共振初步研究

目的 利用血氧水平依赖性(blood oxygenation level-dependent,BOLD)功能磁共振成像(functional magnetic resonance imaging,fMRI)技术探讨首发精神分裂症患者治疗前后认知功能激发图像的特点。方法 13例首发精神分裂症患者入组,用利培酮或氯丙嗪治疗后9例患者复查fMRI。以词语流畅性作业(verbal fluency task,VF)作为任务,采用Block设计,用梯度回波-平面回波成像(GRE-EPI)序列采集数据,经工作站处理后获功能图像。结果 (1)VF激活受试者的额叶(前额叶)、顶叶及颞叶皮层;(2)复查的9例受试者中,7例激活增强,2例激活减弱;(3)治疗后激活增强的7例受试者的双侧额上、中、下回激活有增加趋势,而双侧颞上、中、下回激活有减少趋势(P>0.05);但左额叶背外侧面治疗后的激活明显强于治疗前(P=0.032)。结论 BOLD-fMRI可用于研究人脑的高级认知功能。首发精神分裂症患者治疗前后脑功能图像有明显变化,提示认知缺陷症状是可以治疗的。     

不同亚型轻度认知障碍患者静息态脑功能局部一致性研究

目的探讨遗忘型和非遗忘型轻度认知障碍(mild cognition impairment,MCI)患者局部自发脑活动特点。方法纳入遗忘型MCI(amnesicMCI,aMCI)患者25例,非遗忘型MCI(non-amnesticMCI,naMCI)患者21例和正常对照(normal control,NC)15名进行静息态功能磁共振扫描,通过计算每个给定体素与其最邻近26个体素时间序列的相似性获得全脑局部一致性(regional homogeneity,ReHo)图,比较三组被试全脑ReHo差异。结果 aMCI组右侧额叶ReHo值低于NC组,左侧颞中回和左侧小脑ReHo值高于NC组(P0.05,Alphasim校正);naMCI组前扣带回和右侧额中回ReHo值低于NC组,右侧海马旁回、右侧颞中回和右侧楔前叶ReHo值高于NC组(P0.05,Alphasim校正);aMCI左侧前额叶和左侧颞中回ReHo值高于naMCI组,右侧小脑ReHo值低于naMCI组(P0.05,Alphasim校正)。结论 aMCI和naMCI患者左侧前额叶、左侧颞中回及右侧小脑自发脑功能活动存在差异,这为区别aMCI和naMCI两者脑功能活动特点提供了初步影像学依据。     

抑郁症患者识别负性表情的脑磁源性影像动态变化

目的 利用磁源性影像技术以及表情事件相关识别实验范式探讨抑郁症患者识别负性动态表情的神经网络磁源性影像动态变化的特点.方法 利用脑磁图检测12例抑郁症患者(患者组)及12名年龄、性别、受教育年限近似匹配的健康对照者(对照组)识别负性动态表情视频时的脑部反应.设P＜0.01时,差异均具有统计学意义.结果 与对照组相比,患者组识别负性面部表情时,活动异常主要出现在双侧钩回、双侧颞上回、右额中回、右杏仁核、右颞回下、左梭状回、左枕下回、右海马旁回、左枕舌回、双侧楔前叶、左楔叶等脑区,这些脑区组成的神经网络在识别负性动态表情过程有相应脑区激活异常.结论 抑郁症患者识别负性表情的功能网络的脑磁源性影像动态变化特点与正常人比较差异有统计学意义.     

精神分裂症患者记忆围棋子位置时的脑激活区域

BACKGROUND： Go, a traditional Chinese chess-like game, requires many unknown functions of the brain including attention, imaging, problem solving and processing of spatial working memory. To date, it remains uncertain whether the intellectual activities required to play Go are related to the frontal lobe. OBJECTIVE： To investigate various patterns of brain region activity while schizophrenic patients and normal subjects engaged in memorizing piece placement in the Chinese game of Go. Spatial working memory was measured in order to validate whether the prefrontal lobe participates in this memory process.
DESIGN, TIME AND SETTING： Non-randomized, concurrent control trial was performed at Second Xiangya Hospital of Central South University, between May and December 2004.
PARTICIPANTS： A total of nine Chinese schizophrenic patients with no brain or bodily diseases and not undergoing electroshock treatment, who were in accordance with the DSM-Ⅳ criteria for schizophrenia, as well as thirteen healthy staffs and students with matched age, sex, and education were included. Patients and control subjects had no neurological disorders or mental retardation. In addition, all participants were right-handed. METHODS： The cognitive task for functional magnetic resonance imaging was a block design experiment. Both groups were asked to remember the placement of pieces in the Chinese game of Go on a computer screen. A brain activation map was analyzed in SPM99.
MAIN OUTCOME MEASURES： Brain responses were compared with regard to activation region size, volume, and asymmetry indices. RESULTS： Compared with the control group, the reaction time was significantly delayed in schizophrenics performing the working memory task （P 〈 0.05）. When performing the tasks, normal subjects showed significant activation of the bilateral dorsolateral prefrontal lobe with left dominance; the asymmetry indices were： frontal lobe, ＋0.32; temporal lobe, 0.58; parietal lobe, 0.41 ; and occipital lobe, 0.34. On the other hand, schizophrenics showed right dominance and had a broader activation region of the prefrontal lobe （asymmetry indices： frontal lobe, 0.10; temporal lobe, ＋0.38; parietal lobe, ＋0.24; and occipital lobe, 0.00）. When comparing the normal group subtracted with the schizophrenic group, no significant lateralization was found in the frontal lobes but significant activation was found in the left anterior central gyrus, left middle frontal gyrus and in both sides of the cingulate gyrus. Comparing the schizophrenic group subtracted with the normal group, there was significant right lateralization of the frontal lobe and abnormally activated regions on both sides of the anterior central gyrus, middle frontal gyrus, left inferior frontal gyrus, right medial frontal gyrus and the right insular lobe. CONCLUSION： Different brain activation regions are involved in memorizing the placement of pieces in Chinese Go between schizophrenia and healthy subjects. Schizophrenics showed right dominance and border activation range, indicating that the prefrontal cortex plays an important role in memory information processing and resource allocation when remembering piece placement in the game of Go.     

Anomalous prefrontal-subcortical activation in familial pediatric bipolar disorder: a functional magnetic resonance imaging investigation

BACKGROUND: The neurobiological features of pediatric bipolar disorder (BD) are largely unknown. Children and adolescents with BD may be important to study with functional neuroimaging techniques because of their unique status of early-onset BD and high familial loading for the disorder. Neuroimaging studies of adults with BD have implicated the dorsolateral prefrontal cortex (DLPFC) and anterior cingulate cortex (ACC) in the development of this disorder. OBJECTIVES: To study children and adolescents with BD via functional magnetic resonance imaging using cognitive and affective tasks and to examine possible abnormalities in the DLPFC and ACC, as well as selected subcortical areas, in pediatric familial BD. DESIGN: We evaluated 12 male subjects aged 9 to 18 years with BD who had at least 1 parent with BD as well as 10 age- and IQ-matched healthy male controls. Stimulants were discontinued for at least 24 hours; other medications were continued. Subjects underwent functional magnetic resonance imaging at 3 T while performing a 2-back visuospatial working memory task and an affective task involving the visualization of positively, neutrally, or negatively valenced pictures. SETTING: An academic referral setting, drawing from the Bay Area of San Francisco, Calif. RESULTS: Compared with controls, for the visuospatial working memory task, subjects with BD had greater activation in several areas including the bilateral ACC, left putamen, left thalamus, left DLPFC, and right inferior frontal gyrus. Controls had greater activation in the cerebellar vermis. In viewing negatively valenced pictures, subjects with BD had greater activation in the bilateral DLPFC, inferior frontal gyrus, and right insula. Controls had greater activation in the right posterior cingulate gyrus. For positively valenced pictures, subjects with BD had greater activation in the bilateral caudate and thalamus, left middle/superior frontal gyrus, and left ACC, whereas controls had no areas of greater activation. CONCLUSIONS: Children and adolescents with BD may have underlying abnormalities in the regulation of prefrontal-subcortical circuits. Further functional magnetic resonance imaging studies of attention and mood with greater sample sizes are needed.     

Word and picture matching: a PET study of semantic category effects

We report two positron emission tomography (PET) studies of cerebral activation during picture and word matching tasks, in which we compared directly the processing of stimuli belonging to different semantic categories (animate and inanimate) in the visual (pictures) and verbal (words) modality. In the first experiment, brain activation was measured in eleven healthy adults during a same/different matching task for textures, meaningless shapes and pictures of animals and artefacts (tools). Activations for meaningless shapes when compared to visual texture discrimination were localized in the left occipital and inferior temporal cortex. Animal picture identification, either in the comparison with meaningless shapes and in the direct comparison with non-living pictures, involved primarily activation of occipital regions, namely the lingual gyrus bilaterally and the left fusiform gyrus. For artefact picture identification, in the same comparison with meaningless shape-baseline and in the direct comparison with living pictures, all activations were left hemispheric, through the dorsolateral frontal (Ba 44/6 and 45) and temporal (Ba 21, 20) cortex. In the second experiment, brain activation was measured in eight healthy adults during a same/different matching task for visually presented words referring to animals and manipulable objects (tools); the baseline was a pseudoword discrimination task. When compared with the tool condition, the animal condition activated posterior left hemispheric areas, namely the fusiform (Ba 37) and the inferior occipital gyrus (Ba 18). The right superior parietal lobule (Ba 7) and the left thalamus were also activated. The reverse comparison (tools vs animals) showed left hemispheric activations in the middle temporal gyrus (Ba 21) and precuneus (Ba 7), as well as bilateral activation in the occipital regions. These results are compatible with different brain networks subserving the identification of living and non-living entities; in particular, they indicate a crucial role of the left fusiform gyrus in the processing of animate entities and of the left middle temporal gyrus for tools, both from words and pictures. The activation of other areas, such as the dorsolateral frontal cortex, appears to be specific for the semantic access of tools only from pictures.     

矿难后急性重性创伤后应激障碍症状激发和创伤有关短期记忆提取的功能性磁共振成像研究

目的 探讨急性重性创伤后应激障碍(post traumatic stress disorder,PTSD)患者的脑功能及执行记忆功能时的脑反应.方法 采用功能磁共振成像技术,对经历矿难的10例急性重性PTSD患者(PTSD组)和7例非PTSD对照(非PTSD组)执行症状激发任务,并首次采用1项创伤有关的短期记忆提取任务...     

fMRI differences in encoding and retrieval of pictures due to encoding strategy in the elderly

Functional MRI (fMRI) was used to examine the neural correlates of depth of processing during encoding and retrieval of photographs in older normal volunteers (n = 12). Separate scans were run during deep (natural vs. man-made decision) and shallow (color vs. black-and-white decision) encoding and during old/new recognition of pictures initially presented in one of the two encoding conditions. A baseline condition consisting of a scrambled, color photograph was used as a contrast in each scan. Recognition accuracy was greater for the pictures on which semantic decisions were made at encoding, consistent with the expected levels of processing effect. A mixed-effects model was used to compare fMRI differences between conditions (deep-baseline vs. shallow-baseline) in both encoding and retrieval. For encoding, this contrast revealed greater activation associated with deep encoding in several areas, including the left parahippocampal gyrus (PHG), left middle temporal gyrus, and left anterior thalamus. Increased left hippocampal, right dorsolateral, and inferior frontal activations were found for recognition of items that had been presented in the deep relative to the shallow encoding condition. We speculate that the modulation of activity in these regions by the depth of processing manipulation shows that these regions support effective encoding and successful retrieval. A direct comparison between encoding and retrieval revealed greater activation during retrieval in the medial temporal (right hippocampus and bilateral PHG), anterior cingulate, and bilateral prefrontal (inferior and dorsolateral). Most notably, greater right posterior PHG was found during encoding compared to recognition. Focusing on the medial temporal lobe (MTL) region, our results suggest a greater involvement of both anterior MTL and prefrontal regions in retrieval compared to encoding.