fMRI观察海洛因成瘾戒断者情绪加工中的唤醒度异常

目的 探讨海洛因成瘾戒断者情绪加工中唤醒度异常的脑机制。 方法 通过呈现不同唤醒度的情绪图片对13例海洛因成瘾戒断者(试验组)和13名健康人(对照组)进行fMRI。扫描结束后受试者对图片进行唤醒度评定。利用AFNI软件对脑功能数据进行处理,使用SPSS 13.0统计软件对行为学数据进行分析。 结果 观看情绪图片时,试验组左侧杏仁核和海马、双侧丘脑、扣带回、双侧额上回、额中回、右侧中央前回、双侧颞上回、右侧颞下回、左侧梭状回、双侧尾状核等脑区的激活低于对照组;观看高唤醒度图片时,其右侧丘脑、左侧杏仁核和海马的激活高于观看低唤醒度图片,对照组相反。 结论 海洛因成瘾者的情绪唤醒度加工机制存在损伤。     

情绪记忆性别差异的功能磁共振成像研究

目的通过检测参与情绪记忆相关激活脑区,探讨情绪记忆中性别差异相关的特异性脑机制。方法20名健康被试,实验包括编码和提取两阶段,同时实行功能MRI扫描及记录行为学成绩,利用SPM2对功能数据进行方差分析和简单相关分析。结果男性情绪记忆成功编码主要与右侧杏仁核相关,女性主要与左侧杏仁核相关。男女记忆增强效应均与左侧杏仁核明显相关。男性多激活前额叶不同亚区皮层,而女性多激活杏仁核、海马、梭状回和枕部皮层。结论情绪记忆中杏仁核激活存在男右女左偏侧化优势;这种偏侧化效应在两性的情绪记忆增强效应中不起主要作用。大脑前后部皮层激活也存在性别差异,男女性情绪记忆加工存在相对特异性神经机制。     

内容记忆和来源记忆的功能磁共振成像研究

目的研究内容记忆和来源记忆的脑区激活情况,验证单加工和双加工模型的可靠性。方法16位正常成人。实验材料为504个高频的汉字双字词。任务分四种(学习、对照、内容记忆和来源记忆任务),采用学习-任务-学习-任务设计。利用GE1.5T Signa Horizon LX成像系统采集脑部f MRI数据,通过SPM99软件对f MRI数据进行分析。结果内容记忆和来源记忆均引起双前额中回(BA6)激活。相对于来源记忆,内容记忆较多引起右前额中回(BA46)和右侧海马激活;相对于内容记忆,来源记忆较多引起左前额额中回(BA10)和左侧海马激活。另在来源记忆中,前扣带回(BA32/24),双前额叶下部(BA44/45)和小脑激活较内容记忆明显。结论内容记忆和来源记忆均引起双前额中回激活,但前者较多引起右前额中回激活,而后者较多引起左前额中回激活。内容记忆引起右侧海马激活,而来源记忆引起左侧海马激活。     

阿尔茨海默病情绪记忆相关脑灰质体积改变

目的 探讨阿尔茨海默病（AD）患者情绪记忆改变与灰质容积变化的相关性。方法 对25例AD患者（AD组）及25名正常对照（NC组）进行情绪记忆行为学检测,获取行为学成绩。采用MRI 3D结构相用VBM8和SPM8软件处理,得到相对灰质体积改变的脑区,做为ROI,采用REST软件提值,并与行为学成绩行相关性分析。结果 AD组受试对负性与中性图片反应正确率差异无统计学意义（P=0.56）。与NC组比较,AD组灰质体积缩小的脑区包括双侧颞下回、颞中回、海马、海马旁回、杏仁核、梭状回、楔前叶、后扣带回、左侧脑岛、右侧舌回、左侧额叶眶内侧回、左侧内侧前额叶、右侧额下回岛盖部、左侧中央前回及右侧丘脑（FWE校正,P<0.025）;其中双侧杏仁核、双侧后扣带回、左侧海马、左侧脑岛、左侧颞下回、左侧颞中回、左侧额叶眶内侧回、右侧额下回岛盖部、左侧内侧前额叶的相对灰质体积与情绪图片记忆反应正确率呈正相关（P均<0.05）。结论 AD患者负性图片情绪增强效应损害,可能与杏仁核和海马等情绪记忆系统脑区萎缩有关。     

首发重性抑郁症患者面部表情刺激的脑功能磁共振研究

[目的]探讨抑郁症患者在愉快和悲伤面部表情刺激下的脑功能机制.[方法]对20例首发未服药重性抑郁症患者和20例正常人进行愉快和悲伤面部表情刺激下的脑功能磁共振成像研究.[结果]在愉快和悲伤表情刺激下,相对正常对照,重性抑郁症患者主要表现在前额脑区(包括前扣带)和边缘脑区(海马、海马旁回、杏仁核)的激活.[结论]前额和边缘脑区的损害可能参与了重性抑郁的病理生理机制.     

悲伤和抑郁的脑机制

目的:回顾悲伤和抑郁脑机制研究的最新进展。资料来源:应用计算机检索EBSCO1990-01/2005-02和ProQuest1990-01/2005-02期间与悲伤、抑郁脑机制的相关文章,检索词为“sad,de-pression,cerebralmechanism”,并限定文章的语言种类为English。资料选择:对资料进行初选,选取最近8年与悲伤、抑郁脑机制相关的文章,筛除观点陈旧和观点重复的文章。资料提炼:收集62篇文章,筛除重复研究36篇,纳入26篇用于综述。资料综合:悲伤是人类的一种基本情绪,抑郁是个异源的失调群组,悲伤和抑郁的加工和调节涉及广泛的脑区,特别是和前额叶皮质、扣带前回和杏仁核有着密切的联系。前额叶皮质的功能不对称与接近性或回避性情绪相关联。悲伤诱发时前额叶皮质、扣带前回的激活增加,抑郁更多的和左侧前额叶、扣带前回的激活降低相关联。杏仁核的局部区域脑血流或葡萄糖代率的上升和抑郁症状有联系,悲伤紧张性的不断增加和左侧杏仁核及左侧颞极的激活增加相联系。结论:悲伤和抑郁的加工和调节涉及广泛的大脑区域。其中,前额叶皮质、扣带前回和杏仁核在悲伤和抑郁中扮演着更为重要的角色。其他区域如颞叶、顶叶、基底神经节、丘脑、下丘脑等亦参与其中。     

悲伤和抑郁的脑机制

目的：回顾悲伤和抑郁脑机制研究的最新进展。资料来源：应用计算机检索EBSC01990—01／2005—02和ProQuest1990-01／2005-02期间与悲伤、抑郁脑机制的相关文章，检索词为“sad，depression，cerebral mechanism”，并限定文章的语言种类为English。资料选择：对资料进行初选，选取最近8年与悲伤、抑郁脑机制相关的文章，筛除观点陈旧和观点重复的文章。资料提炼：收集62篇文章，筛除重复研究36篇，纳入26篇用于综述。资料综合：悲伤是人类的一种基本情绪，抑郁是个异源的失调群组，悲伤和抑郁的加工和调节涉及广泛的脑区，特别是和前额叶皮质、扣带前回和杏仁核有着密切的联系。前额叶皮质的功能不对称与接近性或回避性情绪相关联。悲伤诱发时前额叶皮质、扣带前回的激活增加，抑郁更多的和左侧前额叶、扣带前回的激活降低相关联。杏仁核的局部区域脑血流或葡萄糖代率的上升和抑郁症状有联系，悲伤紧张性的不断增加和左侧杏仁核及左侧颞极的激活增加相联系。结论：悲伤和抑郁的加工和调节涉及广泛的大脑区域。其中，前额叶皮质、扣带前回和杏仁核在悲伤和抑郁中扮演着更为重要的角色。其他区域如颞叶、顶叶、基底神经节、丘脑、下丘脑等亦参与其中。     

自我情绪评定量表在老年痴呆人群中的应用

目的 探讨自我情绪评定量表（ Self-Assessment Manikin , SAM ）在老年痴呆人群中的应用。方法 选取老年痴呆患者 128 例,进行痴呆严重程度分级,给予情绪图片刺激后,进行 SAM 量表评定。 结果 轻、中度痴呆患者能有效完成 SAM 量表测试,愉悦度整体低于常模,唤醒度和优势度要普遍高于常模,其中低愉悦、低唤醒水平图片的优势度和常模比较,差异有统计学意义（ P<0.05 ）;低优势度水平图片的唤醒度得分与常模值比较,差异有统计学意义（ P<0.05 ）,其他差异无统计学意义（ P>0.05 ）。 老年痴呆患者对不同维度不同水平的情绪图片的三维度评分散点图显示三者是存在明显关联的,愉悦度和唤醒度散点图分布呈“ V ”型;愉悦度和优势的散点分布图呈斜线型。 SAM 的自我情绪总体评分影响因素依次为照顾者身份、配偶情况、痴呆严重程度、医疗费用等。 结论 SAM 量表能成功的应用在我国轻、中度老年痴呆患者人群中,能在一定程度上客观反映老年痴呆患者对情绪刺激后的主观体验。     

正常老年人无意义图形记忆任务的fMRI研究

目的探讨正常老年人进行记忆任务的实验可行性及激活脑区.方法对11例正常老年志愿者进行无意义图形记忆任务的fMRI实验,实验以组块方式设计,包括第一次记忆组、重复记忆组和再认组.实验数据以SPM99作后处理显示激活脑区.结果 10例受试者的记忆任务完成较好,记忆和再认的激活区域主要集中双侧前额叶、双侧海马旁回(左侧为主)、右侧海马、双侧顶叶(主要为顶上小叶和楔前叶).记忆编码时海马的激活集中在海马头部,而提取时海马的激活则集中在海马的体部及尾部.结论老年人进行fMRI认知实验具有可行性,记忆的编码和提取时需要内侧颞叶海马系统的参与,但所倚重的脑区有微小的差别.     

暴力人群面部表情的功能磁共振变化

目的应用脑功能磁共振探讨暴力人群对愉快和悲伤面部表情认知障碍的脑功能机制。方法 2009年3月8月,应用宾夕法尼亚大学三维彩色愉快和悲伤情绪面部表情图片作为情绪刺激,对男性暴力行为组（n=20）和与之相匹配的正常男性（n=21）,进行功能磁共振扫描,并采用SPM2对数据进行分析。结果愉快情绪图片刺激下,正常组比暴力组激活增加的脑区有左额中回、左前扣带回、左楔前叶、左颞中回、右中央后回和右侧小脑。悲伤情绪图片刺激下,正常组比暴力组激活增加的脑区有左额中回、左后扣带回、左楔前叶、右小脑、左颞中回及颞上回。结论暴力行为者对愉快和悲伤情绪的脑激活减低,主要表现在前额叶-颞叶-边缘脑区。     

Segregated neural representation of distinct emotion dimensions in the prefrontal cortex-an fMRI study

Emotions are frequently characterized by distinct dimensions such as valence, intensity, and recognition. However, the exact neural representation of these dimensions in different prefrontal cortical regions remains unclear. One of the problems in revealing prefrontal cortical representation is that the very same regions are also involved in cognitive functions associated with emotion processing. We therefore conducted an fMRI study involving the viewing of emotional pictures (using the International Affective Picture System; IAPS) and controlled for associated cognitive processing like judgment and preceding attention. Functional activation was correlated with subjective post-scanning ratings of valence, intensity, and recognition. Valence significantly correlated with the functional response in ventromedial prefrontal cortex (VMPFC) and dorsolateral prefrontal cortex (DLPFC), intensity with activation in ventrolateral prefrontal cortex (VLPFC) and dorsomedial prefrontal cortex (DMPFC), and recognition with the functional response in perigenual anterior cingulate cortex (PACC). In conclusion, our results indicate segregated neural representation of the different emotion dimensions in different prefrontal cortical regions.     

Dissociation of working memory processing associated with native and second languages: PET investigation

Verbal working memory plays a significant role in language comprehension and problem-solving. The prefrontal cortex has been suggested as a critical area in working memory. Given that domain-specific dissociations of working memory may exist within the prefrontal cortex, it is possible that there may also be further functional divisions within the verbal working memory processing. While differences in the areas of the brain engaged in native and second languages have been demonstrated, little is known about the dissociation of verbal working memory associated with native and second languages. We have used H2(15)O positron emission tomography in 14 normal subjects in order to identify the neural correlates selectively involved in working memory of native (Korean) and second (English) languages. All subjects were highly proficient in the native language but poorly proficient in the second language. Cognitive tasks were a two-back task for three kinds of visually presented objects: simple pictures, English words, and Korean words. The anterior portion of the right dorsolateral prefrontal cortex and the left superior temporal gyrus were activated in working memory for the native language, whereas the posterior portion of the right dorsolateral prefrontal cortex and the left inferior temporal gyrus were activated in working memory for the second language. The results suggest that the right dorsolateral prefrontal cortex and left temporal lobe may be organized into two discrete, language-related functional systems. Internal phonological processing seems to play a predominant role in working memory processing for the native language with a high proficiency, whereas visual higher order control does so for the second language with a low proficiency.     

Distinguishing specific sexual and general emotional effects in fMRI-subcortical and cortical arousal during erotic picture viewing

Sexual activity involves excitement with high arousal and pleasure as typical features of emotions. Brain activations specifically related to erotic feelings and those related to general emotional processing are therefore hard to disentangle. Using fMRI in 21 healthy subjects (11 males and 10 females), we investigated regions that show activations specifically related to the viewing of sexually intense pictures while controlling for general emotional arousal (GEA) or pleasure. Activations in the ventral striatum and hypothalamus were found to be modulated by the stimulus' specific sexual intensity (SSI) while activations in the anterior cingulate cortex were associated with an interaction between sexual intensity and emotional valence. In contrast, activation in other regions like the dorsomedial prefrontal cortex, the mediodorsal thalamus and the amygdala was associated only with a general emotional component during sexual arousal. No differences were found in these effects when comparing females and males. Our findings demonstrate for the first time neural differentiation between emotional and sexual components in the neural network underlying sexual arousal.     

An fMRI study of differential neural response to affective pictures in schizophrenia

Although emotional dysfunction is considered a fundamental symptom of schizophrenia, studies investigating the neural basis of emotional dysfunction in schizophrenia are few. Using functional magnetic resonance imaging (fMRI) and a task viewing affective pictures, we aimed to examine automatic emotional response and to elucidate the neural basis of impaired emotional processing in schizophrenia. Fifteen healthy volunteers and 15 schizophrenics were studied. During the scans, the subjects were instructed to indicate how each of the presented pictures made them feel. Whole brain activities in response to the affective pictures were measured by fMRI. Controls recruited the neural circuit including amygdaloid-hippocampal region, prefrontal cortex, thalamus, basal ganglia, cerebellum, midbrain, and visual cortex while viewing unpleasant pictures. Despite an equal behavioral result to controls, the patients showed less activation in the components of the circuit (right amygdala, bilateral hippocampal region, medial prefrontal cortex (MPFC), basal ganglia, thalamus, cerebellum, midbrain, and visual cortex). This study demonstrated functional abnormalities in the neural circuit of emotional processing in schizophrenia. In particular, decreased activation in the right amygdala and MPFC appears to be an important finding related to dysfunctional emotional behavior in schizophrenia.     

Facial expressions and complex IAPS pictures: common and differential networks

Neuroimaging studies investigating emotion have commonly used two different visual stimulus formats, facial expressions of emotion or emotionally evocative scenes. However, it remains an important unanswered question whether or not these different stimulus formats entail the same processes. Facial expressions of emotion may elicit more emotion recognition/perception, and evocative pictures may elicit more direct experience of emotion. In spite of these differences, common areas of activation have been reported across different studies, but little work has investigated activations in response to the two stimulus formats in the same subjects. In this fMRI study, we compared BOLD activation patterns to facial expression of emotions and to complex emotional pictures from the International Affective Picture System (IAPS) to determine if these stimuli would activate similar or distinct brain regions. Healthy volunteers passively viewed blocks of expressive faces and IAPS pictures balanced for specific emotion (happy, sad, anger, fear, neutral), interleaved with blocks of fixation. Eye movement, reaction times, and off-line subjective ratings including discrete emotion, valence, and arousal were also recorded. Both faces and IAPS pictures activated similar structures, including the amygdala, posterior hippocampus, ventromedial prefrontal cortex, and visual cortex. In addition, expressive faces uniquely activated the superior temporal gyrus, insula, and anterior cingulate more than IAPS pictures, despite the faces being less arousing. For the most part, these regions were activated in response to all specific emotions; however, some regions responded only to a subset.     

The roles of timing and task order during task switching

The neural bases of the different processes involved in task switching remain poorly identified. Whether distinct brain regions are involved according to the overall structure of the task sequence and the predictability of task timing during task switching is unknown. To address this question, we used functional magnetic resonance imaging and a 2 x 2 factorial design varying timing (fixed/random) and task order (predictable/unpredictable). We hypothesized that predictable task order should activate brain regions involved in long-term memory retrieval because retrieving which task has to be performed constitutes the essential part of what subjects can do to prepare before stimulus presentation. When examining the "pure" main effects of task order/timing predictability/ unpredictability, we found that anticipating task order activated the right hippocampus, the anterior medial prefrontal cortex, and the posterior cingulate cortex, while anticipating task onset timing activated the left middle and superior frontal gyrus. Furthermore, task order unpredictability activated the intraparietal cortex bilaterally while random relative to fixed timing activated the right cerebellum. Interactions between task order and timing were found in a network, which included the left frontopolar cortex and the lateral prefrontal cortex bilaterally. Specifically, the left frontopolar cortex was more activated when both timing and task order were predictable, while the lateral prefrontal cortices were more activated when both task order and timing were unpredictable. These results indicate a hierarchic organization of the prefrontal cortex along a posterioanterior axis as the task becomes more endogenously guided. Finally, we found no evidence for specific brain regions involved in task switching because a bilateral prefronto-parietal network, which was activated in task switching relative to performing each task separately, was no longer activated relative to a control condition, which required subjects to maintain two tasks in memory without switching between them.     

Emotion suppression reduces hippocampal activity during successful memory encoding

People suppressing their emotions while facing an emotional event typically remember it less well. However, the neural mechanisms underlying the impairing effect of emotion suppression on successful memory encoding are not well understood. Because successful memory encoding relies on the hippocampus and the amygdala, we hypothesized that memory impairments due to emotion suppression are associated with down-regulated activity in these brain areas. 59 healthy females were instructed either to simply watch the pictures or to down-regulate their emotions by using a response-focused emotion suppression strategy. Brain activity was recorded using functional magnetic resonance imaging (fMRI), and free recall of pictures was tested afterwards. As expected, suppressing one's emotions resulted in impaired recall of the pictures. On the neural level, the memory impairments were associated with reduced activity in the right hippocampus during successful encoding. No significant effects were observed in the amygdala. In addition, functional connectivity between the hippocampus and the right dorsolateral prefrontal cortex was strongly reduced during emotion suppression, and these reductions predicted free-recall performance. Our results indicate that emotion suppression interferes with memory encoding on the hippocampal level, possibly by decoupling hippocampal and prefrontal encoding processes, suggesting that response-focused emotion suppression might be an adaptive strategy for impairing hippocampal memory formation in highly arousing situations.