空间记忆广度的脑功能磁共振研究

目的本实验拟通过功能磁共振研究参与正常人空间记忆广度任务的脑功能区和特点。方法10名右利手健康志愿者进行一项空间记忆广度任务作业的同时进行脑功能磁共振扫描,实验采用组块设计,实验任务与对照任务交替进行,数据采用SPM99软件进行数据分析和脑功能区定位。结果当统计阈值设定为P(0.0001时,被试者的双侧Brodmann区(Brodmann area,BA)6区(额中下回)、右BA9区(额中下回)、左额下回BA47区、双侧顶叶BA7区(楔前叶、顶上小叶)、双侧顶叶BA40区(缘上回),右枕叶BA18、19区、右海马回BA30区、左枕颞交界处BA37区、双侧顶叶中央后回BA3区、左顶叶中央后回BA2区、右中央前回BA4区及左中脑黑质、右小脑均有激活,以顶叶的激活最为显著,其次为额叶、枕叶,其中额叶的BA9区和枕叶的BA18、19区及海马回、小脑的激活有极其明显的右侧半球优势;当统计阈值设定为P(0.001时,脑激活区增加了右前扣带回BA25区,右侧额下回BA47区、左额叶BA9区,左侧枕叶BA17、18、19区及右屏状核,左丘脑侧后核。结论与空间记忆广度有关的主要脑区有BA9、6、7、40、19区和海马回、小脑。它们在进行短时空间记忆任务时所起的作用不同。通过fMRI的研究,揭示了大脑进行空间信息的处理过程。     

汉语单字词音、义加工的脑激活模式

目的：研究汉字音、义加工的脑机制。方法：采用汉字单字词为实验材料，通过功能磁共振成像扫描执行语音和语义两种认知任务的脑区。结果：语音任务激活的脑区有，左侧顶叶下部和颞上回(BA 40／39／22，BA：Brodmann Area，即布鲁德曼分区，下同)，左侧枕中回(BA18／19)，右侧枕下回(BA18／19)，以及左中央前回(BA6)。语义任务激活的脑区有，左侧顶叶下部(BA40／39)和左侧颞上回(BA22)，左侧额下回(BA10／47)，右侧额中回和额上回(BA10／11)，以及左侧额中回(BA11)。语义任务减去语音任务激活的脑区有，左侧额下回(BA47)，左侧海马(BA36)和右侧海马旁回(BA36)。语音任务减去语义任务没有发现任何脑区的显著激活。结论：在语义任务中与语音有关的脑区得到激活；而在语音任务中与语义有关的脑区没有激活。     

汉语单字词音、义加工的脑激活模式

目的:研究汉字音、义加工的脑机制.方法:采用汉字单字词为实验材料,通过功能磁共振成像扫描执行语音和语义两种认知任务的脑区.结果:语音任务激活的脑区有,左侧顶叶下部和颞上回(BA 40/39/22,BA:Brodmann Area,即布鲁德曼分区,下同),左侧枕中回(BA 18/19),右侧枕下回(BA 18/19),以及左中央前回(BA6).语义任务激活的脑区有,左侧顶叶下部(BA 40/39)和左侧颞上回(BA 22),左侧额下回(BA 10/47),右侧额中回和额上回(BA 10/11),以及左侧额中回(BA 11).语义任务减去语音任务激活的脑区有,左侧额下回(BA47),左侧海马(BA 36)和右侧海马旁回(BA 36).语音任务减去语义任务没有发现任何脑区的显著激活.结论:在语义任务中与语音有关的脑区得到激活;而在语音任务中与语义有关的脑区没有激活.     

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。     

汉语语音加工的神经基础：图片刺激下的功能磁共振成像

对语音加工的研究使用文字刺激的较多。实验采用fMRI技术,使用图片刺激,在汉语押韵任务下,考察与汉语语音加工相关的脑区。对13名以汉语为母语的在校健康本科大学生的测试结果显示：图片刺激下汉语的语音加工会激活额叶、顶叶和枕颞联合皮质,包括额下回、额中回、缘上回、枕颞内侧回等。此外,图片刺激下汉语语音加工在颞上回BA22区引起了激活,但在颞中回未出现激活。     

语义记忆脑功能区偏侧化的功能磁共振成像研究

目的 通过功能磁共振成像(fMRI)技术检测健康人脑语义记忆功能区的分布特点.方法 14名右利手健康志愿者进行配对词语联想学习记忆任务时行fMRI扫描,该任务可有代表性地反映受试者的语义记忆.实验采用组块设计并选用SPM99软件行数据分析和脑功能区定位,记录各激活脑区的像素值并计算偏侧化指数LI值.结果 经单样本t检验,阈值设为P＜0.005时,记忆编码时主要激活脑区为左枕叶和左额上中回,提取时主要激活左顶叶、左枕叶和左额中下回;而右半球在两阶段均较少激活.编码和提取激活脑区像素值LI值分别为0.81和0.73.结论 语义记忆的脑功能区有显著的左半球优势;记忆编码和提取阶段所激活的脑区有所差别,但均主要分布于左外侧裂语言区的周围.     

首发精神分裂症患者倒背数字作业的fMEI研究

目的利用功能磁共振成像(fMRI)探讨首发精神分裂症患者倒背数字作业激发图像的特点.方法 36例符合ICD-10诊断标准的(首发)精神分裂症患者及18名健康志愿者进行以倒背数字作业(backward digit span task, BDST)作为刺激模式、采用组块(block)设计的fMRI检查,经工作站处理后获功能图像.用阳性和阴性症状量表(PANSS)评价精神分裂症患者精神症状的严重程度. 结果 (1)健康志愿者与精神分裂症患者激活脑区的范围均较广泛,健康志愿者的左侧额上回、双侧额中回、左侧额下回、左侧中央前回、左侧顶上小叶、左侧缘上回、左侧颞下回及左侧枕颞外侧回等脑区均有明显激活.两组激活的脑区在额叶、颞叶、顶叶、枕叶及扣带回的分布,以及各脑区内部分布的差异均没有显著性(P>0.05).(2)健康志愿者与精神分裂症患者激活计数左侧额上回分别为16和11,左侧额下回分别为15和12,左侧中央前回分别为16和17,左侧颞下回分别为14和12,左侧顶上小叶分别为14和14,左侧缘上回分别为14和7,左侧枕颞外侧回分别为14和7,右侧中央前回分别为13和7,右侧枕颞外侧回分别为11和8,两组上述部位激活计数的差异均有显著性(P均＜0.05).(3)健康志愿者与精神分裂症患者左侧额叶背外侧的激活平均体积分别为(362±296)个体素和(79±101)个体素,差异有非常显著性(P=0.001);右侧顶叶后下部的激活平均体积分别为(448±273)个体素和(193±236)个体素,差异有显著性(P=0.039). 结论早期精神分裂症患者可能存在工作记忆缺陷,包括激活信息的保持及执行控制过程,激活信息的保持缺陷可能与左侧额叶腹外侧及顶叶后下部的功能低下有关,而执行控制缺陷可能与左侧额叶背外侧的功能低下有关.     

抑郁症患者对正性面部表情功能识别

目的：利用任务态功能核磁共振成像技术,初步探讨抗抑郁治疗对正性情绪识别脑区功能的影响。方法：检测19例抑郁症患者治疗前和治疗10周后在识别正性及中性面部表情视频时的激活脑区,并与19例匹配的健康者对照比较。结果：与正常对照组相比,治疗前抑郁症患者左右颞上回（BA39）、左后扣带回（BA23）、右后扣带回（BA30）、左丘脑、右岛叶（BA13）等脑区激活显著降低;治疗后患者左颞上回（BA39）、右颞上回（BA22）、左颞中回（BA37）、左右海马旁回（BA30）、右后扣带回（BA29）、右梭状回（BA36）、左额中回（BA8）、右额下回（BA47）、左顶下小叶（BA40）、右岛叶（BA13）等脑区激活较治疗前增强;但与正常组相比,左颞上回（BA22）、左额中回（BA10）、左梭状回（BA20）、左楔叶（BA19）、右顶上小叶（BA7）、右岛叶（BA13）等脑区激活仍存在一定程度的降低。结论：经抗抑郁治疗,抑郁症患者正性情绪识别脑区功能较治疗前有所改善,但与正常对照组相比,仍存在一定程度的功能损害。进一步证实了积极有效的抗抑郁治疗能够部分逆转正性情绪相关脑区损害。     

注意缺陷/多动障碍工作记忆的bold-功能磁共振成像研究

目的应用bold-功能磁共振成像(bold-fMRI)技术来研究注意缺陷/多动障碍(AD/HD)患者的工作记忆。并探讨使用哌醋甲酯1个月治疗前后AD/HD患者的脑部激活的改变情况。方法利用倒数n刺激模式(n-back)对7例AD/HD(注意缺陷为主型)和7名正常人进行blod-fMRI检查,对照研究AD/HD患者在工作记忆时涉及的各脑区的激活情况。结果AD/HD组治疗后的1-back任务较治疗前1-back任务在右额下回和右额中回激活明显,二者有显著性差异(P<0.05);AD/HD组在治疗后的2-back任务较治疗前2-back任务在左额下回和左顶叶后下部激活明显(P<0.05)。正常组的1-back任务与患者组治疗前的1-back任务比较没有显著性差异,正常组的2-back任务与患者组治疗前2-back任务比较在左额下回和左顶叶后下部激活明显(P<0.05)。结论AD/HD障碍患者存在执行功能方面的缺陷,AD/HD患者的语义性工作记忆缺损可能与前额叶和顶叶的功能缺陷有关。     

执行37分钟听觉Odd-ball任务中事件相关电位变化与注意的关系

背景：许多报道只是分别观察了执行Oddball任务完成过程中事件相关电位各成分的变化,没有结合实验任务模式全面分析各成分的变化及其可能存在的内在联系。 目的：通过测定健康人在执行连续37 min听觉辨别Odd-ball任务过程中的事件相关电位,分析事件相关电位各成分的变化特征与注意的关系。 设计、时间及地点：经典的37 min持续Oddball听觉辨别任务及盲法评估试验,于2003-04/2007-07在日本北九州产业医科大学康复科完成。 对象：20名健康在读大学生,全部为右利手,试验前所有学生均签署知情同意书。 方法：在执行任务过程中,学生观察以10%的概率出现的2 kHz短音靶刺激,靶刺激是随机分布于以90%的概率出现的 1 kHz短音非靶刺激之间,全部实验过程为37 min,包括1 214个声音刺激。前4 min为练习阶段,让学生熟悉任务,之后开始真正的实验过程,将其划分为阶段1,阶段2,阶段3,每阶段为10.9分。 主要观察指标：在额叶、顶叶和额顶中点采集靶刺激和非靶刺激的事件相关电位,非靶刺激包括靶刺激之前第1个和之后第1个非靶刺激的事件相关电位。除了用传统的平均加权法进行研究外,同时进行了单次P3成分分析。实验结束后,所有学生填写问卷,要求填写在各个实验阶段中的主观感受包括他们的清醒度、注意程度和对实验的兴趣程度等。 结果：①各反应电位在不同实验阶段的变化：靶刺激之前第1个非靶刺激的事件相关电位的N1波幅、靶刺激N2的波幅及靶刺激P3的波幅在实验的不同阶段发生显著变化。②不同反应电位之间的比较：靶刺激之前第1个非靶刺激的事件相关电位的N1波幅显著小于靶刺激之后第1个非靶刺激的事件相关电位和靶刺激的N1(实验阶段2、3的额叶、额顶中点和顶叶);靶刺激之前第1个非靶刺激的事件相关电位的P2潜伏期显著小于靶刺激之后第1个非靶刺激的事件相关电位的P2潜伏期(实验阶段2的额叶、额顶中点和顶叶位置上和实验阶段3的额叶);靶刺激之前第1个非靶刺激的事件相关电位的P2的波幅显著小于靶刺激之后第1个非靶刺激的事件相关电位的P2波幅(实验阶段2的额顶中点、在实验阶段3的额叶、额顶中点和顶叶);认知电位变化最敏感区在额叶。③总的平均加权的靶刺激之前第1个非靶刺激的事件相关电位波形。有正负(N1-P2)波峰复合波形,而且在刺激启动后300 ms回到基线水平,而总平均加权的靶刺激之后第1个非靶刺激的事件相关电位波形的正负(N1-P2)复合波峰的连续负波在刺激启动后450 ms之后回到基线水平(额叶和额顶中点)。④事件相关电位的单次分析显示类型2(非P3成分)出现的百分率在额叶位置上显著大于在顶叶位置(实验阶段1,2和3);类型2出现的百分率在实验阶段3的显著大于在实验阶段1(额叶和额顶中点)。⑤在各个实验阶段中,反应时间差异无显著性意义。⑥根据问卷调查,所有的被测试者均认为试验任务非常简单,测试早期处于紧张、全神贯注的状态,随着试验的进展感到轻松、单调和机械化的完成任务,注意力时有分散,但未在测试过程中入睡。 结论：在执行37 min听觉辨别任务过程中,事件相关电位各成分的变化是认知调整的结果,各成分的变化存在内在的联系,推测这种变化与被检者适应过程有关,并直接反映注意不同因素的影响。     

太溪和丘墟穴捻针时不同脑功能区的激活

A number of previous studies of acupuncture acupoint specificity have used sham acupoints,sham acupuncture or meridian acupoints at a great distance from each other as controls in functional MRI (fMRI) experiments.However,few studies have compared different meridian acupoints within the same segment,which are associated with similarly intense needle sensations.We performed fMRI on 12 healthy young volunteers and observed differences in brain activation elicited by acupuncture of the Taixi (KI 3) and Qiuxu (GB 40) acupoints.Acupuncture was applied at the Taixi and Qiuxu acupoints,using a multiple-block fMRI design with three blocks,involving three alternations of resting and task phases.After scanning,needle sensation was assessed.The behavioral results revealed that the subjective needle sensation was similar between the Taixi and Qiuxu acupoints.The fMRI results revealed that acupuncture at the right Taixi acupoint activated the right superior temporal gyrus (BA 22),left middle frontal gyrus (BA 46) and inferior frontal gyrus (BA 45),bilateral parietal lobe postcentral gyrus (BA 2),right parietal lobe (BA 3),and left parietal lobe (BA 40).Acupuncture at the right Qiuxu acupoint activated the left superior temporal gyrus (BA 42),right parietal lobe postcentral gyrus (BA 40,BA 43),right inferior frontal gyrus (BA 47),bilateral superior temporal gyrus (BA 22),and right insula BA13.These results suggest that the right Taixi and Qiuxu acupoints activated different brain areas.     

Acupuncture at the Taixi （KI3） acupoint activates cerebral neurons in elderly patients with mild cognitive impairment

Our previous ifndings have demonstrated that acupuncture at the Taixi （KI3） acupoint in healthy youths can activate neurons in cognitive-related cerebral cortex. Here, we investigated whether acupuncture at this acupoint in elderly patients with mild cognitive impairment can also activate neurons in these regions. Resting state and task-related functional magnetic resonance imaging showed that the pinprick senstation of acupuncture at the Taixi acupoint differed signiifcantly between elderly patients with mild cognitive impairment and healthy elderly controls. Results showed that 20 brain regions were activated in both groups of participants, including the bi-lateral anterior cingulate gyrus （Brodmann areas [BA] 32, 24）, left medial frontal cortex （BA 9, 10, 11）, left cuneus （BA 19）, left middle frontal gyrus （BA 11）, left lingual gyrus （BA 18）, right medial frontal gyrus （BA 11）, bilateral inferior frontal gyrus （BA 47）, left superior frontal gyrus （BA11）, right cuneus （BA 19, 18）, right superior temporal gyrus （BA 38）, left subcallosal gyrus （BA 47）, bilateral precuneus （BA 19）, right medial frontal gyrus （BA 10）, right superior frontal （BA 11）, left cingulate gyrus （BA 32）, left precentral gyrus （BA 6）, and right fusiform gyrus （BA 19）. These results suggest that acupuncture at the Taixi acupoint in elderly patients with mild cogni-tive impairment can also activate some brain regions.     

Interconnected large-scale systems for three fundamental cognitive tasks revealed by functional MRI

The specific brain areas required to execute each of three fundamental cognitive tasks - object naming, same-different discrimination, and integer computation - are determined by whole-brain functional magnetic resonance imaging (fMRI) using a novel technique optimized for the isolation of neurocognitive systems. This technique (1) conjoins the activity associated with identical or nearly identical tasks performed in multiple sensory modalities (conjunction) and (2) isolates the activity conserved across multiple subjects (conservation). Cortical regions isolated by this technique are, thus, presumed associated with cognitive functions that are both distinguished from primary sensory processes and from individual differences. The object-naming system consisted of four brain areas: left inferior frontal gyrus, Brodmann's areas (BAs) 45 and 44; left superior temporal gyrus, BA 22; and left medial frontal gyrus, BA 6. The same-different discrimination system consisted of three brain areas: right inferior parietal lobule, BA 40; right precentral gyrus, BA 6; and left medial frontal gyrus, BA 6. The integer computation system consisted of five brain areas: right middle frontal gyrus, BA 6; right precentral gyrus, BA 6; left inferior parietal lobule, BA 40; left inferior frontal gyrus, BA 44; and left medial frontal gyrus, BA 6. All three neurocognitive systems shared one common cortical region, the left medial frontal gyrus, the object-naming and integer computation systems shared the left inferior frontal gyrus, and the integer computation and same-different discrimination systems shared the right precentral gyrus. These results are consistent with connectionist models of cognitive processes where specific sets of remote brain areas are assumed to be transiently bound together as functional units to enable these functions, and further suggest a superorganization of neurocognitive systems where single brain areas serve as elements of multiple functional systems.     

Relative Changes in Regional Cerebral Blood Flow During Spinal Cord Stimulation in Patients with Refractory Angina Pectoris

Spinal cord stimulation applied at thoracic level 1 (T1) has a neurally mediated anti-anginal effect based on anti-ischaemic action in the myocardium. Positron emission tomography was used to study which higher brain centres are influenced by spinal cord stimulation. Nine patients with a spinal cord stimulator for angina pectoris were studied using H₂¹⁵O as a flow tracer. Relative changes in regional cerebral blood flow related to stimulation compared with non-stimulation were assessed and analysed using the method of statistical parametric mapping. Increased regional cerebral blood flow was observed in the left ventrolateral periaqueductal grey, the medial prefrontal cortex [Brodmann area (BA) 9/10], the dorsomedial thalamus bilaterally, the left medial temporal gyrus (BA 21), the left pulvinar of the thalamus, bilaterally in the posterior caudate nucleus, and the posterior cingulate cortex (BA 30). Relative decreases in rCBF were noticed bilaterally in the insular cortex (BA 20/21 and BA 38), the right inferior temporal gyrus (BA 19/37), the right inferior frontal gyrus (BA 45), the left inferior parietal lobulus (BA 40), the medial temporal gyrus (BA 39) and the right anterior cingulate cortex (BA 24). It is concluded that spinal cord stimulation used as an additional treatment for angina applied at TI modulates regional cerebral blood flow in brain areas known to be associated with nociception and in areas associated with cardiovascular control.     

Developmental and skill effects on the neural correlates of semantic processing to visually presented words

Functional magnetic resonance imaging (fMRI) was used to explore the neural correlates of semantic judgments to visual words in a group of 9- to 15-year-old children. Subjects were asked to indicate if word pairs were related in meaning. Consistent with previous findings in adults, children showed activation in bilateral inferior frontal gyri (Brodmann area [BA] 47, 45) and left middle temporal gyrus (BA 21). Words with strong semantic association elicited significantly greater activation in bilateral inferior parietal lobules (BA 40), suggesting stronger integration of highly related semantic features. By contrast, words with weak semantic association elicited greater activation in left inferior frontal gyrus (BA 45) and middle temporal gyrus (BA 21), suggesting more difficult feature search and more extensive access to semantic representations. We also examined whether age and skill explained unique variance in the patterns of activation. Increasing age was correlated with greater activation in left middle temporal gyrus (BA 21) and inferior parietal lobule (BA 40), suggesting that older children have more elaborated semantic representations and more complete semantic integration processes, respectively. Decreasing age was correlated with activation in right superior temporal gyrus (BA 22) and decreasing accuracy was correlated with activation in right middle temporal gyrus (BA 21), suggesting the engagement of ancillary systems in the right hemisphere for younger and lower-skill children.     

An fMRI study comparing brain activation between word generation and electrical stimulation of language-implicated acupoints

We compared the brain activation on functional magnetic resonance imaging (MRI) during word generation with the activation during electrical stimulation of two language-implicated acupoints in 17 healthy, Mandarin-speaking, Chinese male volunteers (age 19-26 years). All subjects were strongly right handed according to a handedness inventory. Using a standard functional MRI procedure and a word-generation paradigm, significant activation was seen in the left and right inferior frontal gyri (BA 44, 45) as well as the left superior temporal gyrus (BA 22, 42). Stronger activation with a larger volume was seen in the left hemisphere. Electrical stimulation of either one of the two language-implicated acupoints, SJ 8 (11 subjects) and Du 15 (6 subjects), without the word-generation paradigm in the same cohort, produced significant activation in the right inferior frontal gyrus (BA 44, 46) and in the left and right superior temporal gyri (BA 22, 42), respectively. Nevertheless, no activation was seen in the left inferior frontal gyrus. In addition, electrical stimulation of the adjacent non-acupoints did not produce any significant brain activation. Although our results support the notion of acupoint-brain activation, applying acupuncture at SJ 8 or Du 15 does not activate the typical language areas in the left inferior frontal cortex.     

Neuroanatomical discrimination between manipulating and maintaining processes involved in verbal working memory; a functional MRI study

We used functional magnetic resonance imaging (fMRI) to investigate neural correlates of processes concerning store and manipulation in verbal working memory. We prepared a revised lag 1 digit span, digit span and a simple number detection task. Specific activities in association with manipulating process were identified in the right middle (BA 9/46) and left precentral gyrus (BA 6). Activated areas specific to maintaining process were detected in the right middle (right BA 11/10) and medial (BA 6) frontal gyri, the right inferior parietal lobule (BA 40), and the left middle (BA 9) and inferior frontal gyri (BA 44). The process-nonspecific activated areas common to two processes were identified in the right inferior frontal gyrus (BA 47) and the left superior parietal lobule (BA 7). Using the signal percent change of each subject, we calculated the correlation coefficients among each activated area. The results of this analysis showed that two processes of verbal working memory were clearly discriminated. The two essential processes of manipulation and maintenance in working memory seem to activate process-specific and overlapping (process-nonspecific) areas, but the patterns of combination were definitely different.