社会比较对象对后悔情绪波动性的影响:一项静息态fMRI研究

目的采用连续风险决策任务范式,通过功能核磁共振技术来探究在静息状态下脑区之间功能连接对于不同社会比较对象所引起的后悔情绪波动性的影响。材料与方法共有38名健康大学生被试参与本研究。实验中,被试需要假想有两个不同的对手(亲密好友与陌生人),他们会和自己同时完成连续风险决策任务,双方的结果会同时呈现在一起,被试根据双方结果进行情绪评分。所采集到的静息态数据通过功能磁共振静息态数据处理助手(data processing assistant for resting-state fMRI,DPARSF)来处理并计算脑岛(insula)与眶额叶皮层(orbital frontal cortex)等其他脑区的功能连接值,最后进一步将功能连接值与情绪评分指标(情绪波动性)及社会比较量表进行相关分析。结果在收益情境下,个体的结果比陌生人差时,脑岛与眶额叶皮层的功能连接与被试的情绪波动性呈负相关(r=-0.399,P0.05),该功能连接也与个体的社会比较能力呈负相关(r=-0.472,P0.01)。结论个体在静息状态下,脑岛与眶额叶皮层的功能连接与个体在面对陌生人时的情绪波动性及社会比较能力有关。     

经济状况对不公平感相关决策的影响:基于静息态的fMRI研究

目的使用最后通牒博弈任务,通过静息态功能磁共振成像技术探究功能连接对于提议者经济状况对回应者不公平感相关决策产生影响的预测作用。材料与方法 30名健康被试参与本研究。在任务中,被试首先会得知提议者的经济状况(好或差),之后会得知来自提议者的分配方案,他们可以选择接受或拒绝该分配。本研究采用被试的拒绝率和公平感评分来衡量提议者经济状况对回应者进行决策的影响。通过静息态功能磁共振数据处理助手(data processing assistant for resting-state fMRI,DPARSF)处理采集到的静息态数据并计算右侧背外侧前额叶皮层及右侧丘脑与全脑体素的功能连接值,进一步将功能连接值与拒绝率和公平感评分进行相关分析。结果当不公平分配来自于经济状况较好提议者时,右侧背外侧前额叶皮层和右侧内侧前额叶皮层的功能连接与拒绝率之间呈负相关(r=-0.80,P0.01),右侧丘脑与左侧内侧前额叶皮层的功能连接与公平感评分之间呈负相关(r=-0.59,P0.01)。结论在静息状态下背外侧前额叶皮层、丘脑及内侧前额叶皮层间的功能连接对于经济状况对不公平感相关决策的影响具有一定的预测作用。     

帕金森病患者静息态下脑活动的局部一致性

目的 利用fMRI局部一致性(ReHo)方法探测帕金森病(PD)在静息状态下是否存在脑活动异常。 方法 对16例PD患者(PD组)和12名正常对照者(对照组)进行静息状态fMRI,应用ReHo方法处理fMRI数据,得出PD患者ReHo异常的脑区,并对存在组间差异的脑区ReHo与PD综合评分分数(UPDRS)进行相关分析。 结果 ①PD组ReHo显著增高的脑区包括双侧小脑前叶、右侧颞下回、双侧豆状核、双侧丘脑、左侧尾状核、右侧辅助运动区和双侧中央前回;ReHo显著降低的脑区为左侧小脑后叶、右侧前额叶背外侧皮层、左侧楔前叶和右侧顶下小叶;②多处PD组与对照组存在差异的脑区ReHo与UPDRS得分呈显著正相关。 结论 PD患者在静息状态下即存在脑功能异常;ReHo方法可能有助于研究PD患者静息状态脑活动。     

封闭隔离环境暴露对海员脑功能影响的静息态fMRI研究

目的 探讨海上封闭隔离环境及暴露年限对海员脑功能活动的影响,为预防职业环境暴露对海员脑功能损伤提供依据。方法 于2023年8月招募30名长期从事海上作业的男性职业海员作为海员组,年龄19～29岁,工作年限1～11年,在三亚市人民医院采用Magneton Skyra 3.0 T磁共振扫描仪进行静息态脑功能磁共振成像;匹配无海上作业经历的普通被试30名作为对照组,年龄18～28岁,Magneton Skyra 3.0 T静息态磁共振数据从OpenNeuro公共数据库下载。计算两组静息态ALFF、fALFF和ReHo指标,采用双样本t检验比较两组间脑区ALFF、fALFF和ReHo的差异,进一步采用偏相关分析法分析ALFF、fALFF和ReHo值与海员工作年限和出海年限的相关性。结果 与对照组相比,海员组右侧中央后回和右侧小脑脚1区的ALFF值较高,左侧嗅皮质的ALFF值较低;左内侧和旁扣带脑回以及右颞级颞上回的fALFF值较高,右侧枕中回、左侧顶下缘角回、左侧中央前回和右侧中央前回的fALFF值较低;右侧海马旁回ReHo值增高,右侧颞下回、右侧眶部额中回、左侧顶下缘角回、左侧角回、右侧颞中...     

难治性抑郁症患者静息状态默认网络的改变

目的 探索难治性抑郁症(TRD)患者脑静息状态默认网络与正常对照组间的差异.方法 10例TRD患者和12名对照者接受440 s的静息脑功能扫描.运用功能连接分析得出个体的静息状态默认网络并进行组间比较.结果 与对照组比较,TRD组双侧颞中回、直回、楔前回、左侧眶回、右侧顶下小叶与后扣带回的连接功能减弱.结论 TRD患者的静息默认网络连接中多个脑区活动减弱,可能导致患者自我控制和情感行为功能异常.     

静息态功能磁共振成像观察正常人听觉皮层功能

目的 探讨正常人听觉皮层与全脑的正相关及负相关的功能连接.方法 采用静息态下平面回波成像技术采集44名健康受试者fMRI数据,分别以左侧及右侧AⅠ区为种子点,用功能连接的方法观察左、右大脑初级听觉皮层与全脑的正相关及负相关功能连接脑图.结果 分别以双侧AⅠ区为种子点时,正激活的脑网络主要包含双侧AⅠ、AⅡ、岛叶、辅助运动区及扣带回,以同侧为主;与右侧AⅠ区相关的正激活脑区还包括同侧背侧丘脑.与双侧AⅠ区相关的负激活脑网络与脑默认网络大体一致,主要包括双侧后扣带回/楔前叶、额叶内侧回、顶下小叶,双侧小脑半球可见明显激活.结论 静息态磁共振功能连接可满意显示听觉皮层的连接脑图.正相关功能连接主要局限在听觉系统内,负相关功能连接类似于默认网络.     

2型糖尿病患者下丘脑功能连接的静息态功能磁共振研究

目的利用静息态功能磁共振技术探索2型糖尿病(T2DM)患者下丘脑与其他脑区功能连接的改变,明确T2DM是否损伤下丘脑的相关功能连接。材料与方法本研究共纳入59名T2DM患者及49名对照组志愿者,通过德国西门子MR仪采集T1WI、T2WI、T2压水序列、高分辨率3D T1WI结构像和静息态功能数据,计算下丘脑与全脑体素的功能连接值并进行组间比较,然后提取组间存在显著差异脑区的功能连接平均值并对其与临床数据进行相关性分析。结果 T2DM患者左、右侧下丘脑与右侧桥脑、左背外侧前额叶、眶额皮层、左顶下小叶、右侧枕中回间的功能连接强度均低于正常组(P0.05)。除此之外,左侧下丘脑与左侧梭状回、右侧颞下回、左侧楔前叶间的功能连接强度显著减低,左侧下丘脑与左侧岛叶间的功能连接强度显著增高(P0.05);右侧下丘脑与左侧舌回、右侧中央前回/右侧中央后回间的功能连接强度显著减低(P0.05)。相关性分析结果显示左侧下丘脑-左背外侧前额叶间功能连接强度的减低与糖化血红蛋白值存在负相关性(r=–0.24,P=0.04)。结论 T2DM损害了下丘脑与多个脑区的功能连接,其中同侧下丘脑与背外侧前额叶间功能连接减低与糖尿病严重程度相关。静息态功能磁共振能够反映2型糖尿病的严重程度。     

帕金森病静息态脑默认状态网络的观察

目的 应用功能连接MR成像技术观察帕金森病(PD)患者静息态脑默认状态网络的改变.方法 选择14例PD患者和14名健康志愿者,以双侧后扣带回作为种子点,分别进行静息态脑功能磁共振扫描,分析PD患者与健康志愿者的脑功能连接情况和差异. 结果与健康志愿组相比,PD患者的一些脑区存在异常功能连接,具体表现为:左顶下小叶、右侧楔前叶、前额叶中内侧、左侧颞上回等脑区与后扣带回功能连接减低;左侧小脑半球、左侧中央后回、左侧顶上小叶、左侧楔前叶、右侧颞下回、右侧楔叶、右侧舌回、左侧颞中回等脑区与后扣带回功能连接增强. 结论 静息态下帕金森病患者默认状态网络内脑区间的连接功能存在异常.     

皮质下脑卒中对运动想象有关脑区功能连接的影响

目的:本研究拟运用静息态功能磁共振成像探讨皮质下脑卒中患者运动想象有关脑区功能连接状况。方法:对24例病灶位于左侧运动通路的皮质下脑卒中患者和年龄、性别相匹配的24例正常对照进行静息态脑功能磁共振成像扫描,以病变侧(左侧)顶下小叶为种子点,计算它与其他脑区的功能连接,利用双样本t检验对比分析两组受试者静息态功能连接差异。结果:与正常对照比较,脑卒中组的运动想象相关脑区之间功能连接发生显著变化。脑卒中组病变侧顶下小叶与病变对侧脑功能连接显著下降,涉及的脑区(顶下小叶、辅助运动皮质、运动前区、额下回岛盖部和枕中回)多于病变同侧(辅助运动皮质和运动前区);顶下小叶与病变同侧的额下回岛盖部和双侧小脑外侧部的功能连接显著增加。结论:静息态磁共振成像功能连接分析成功显示皮质下脑卒中导致运动想象相关脑区功能连接受损的客观存在。     

2型糖尿病患者眶额皮层相关功能连接的功能MRI研究

目的探索2型糖尿病对眶额皮层与其它脑区之间的相关功能连接是否存在异常。材料与方法对27名不伴有脑血管病变影像征象的2型糖尿病患者及21名正常志愿者进行常规MRI及静息态功能MRI扫描,计算双侧眶额皮层与全脑其它体素间的功能连接值,并进行组间比较,选取组间具有显著差异的脑区,并计算其功能连接的平均值,与临床指标做相关性分析。结果与正常对照组相比,2型糖尿病患者左侧眶额皮层内侧后部与左侧中脑、右侧下丘脑、双侧丘脑的功能连接强度显著减低。其中2型糖尿病患者左侧眶额皮层内侧后部与左侧中脑之间的功能连接平均值与空腹血糖值存在正相关(t=2.3727,P=0.028)。结论 2型糖尿病患者眶额皮层与多个脑区的功能连接存在异常,其中左侧眶额皮层内侧后部与左侧中脑之间的功能连接异常与血糖控制的好坏程度相关。说明2型糖尿病可能损伤了奖赏系统的相关通路,从而导致摄食紊乱。     

社会评价威胁对社会困境中决策行为的影响:基于静息态fMRI的研究

目的采用囚徒困境任务,通过静息态功能磁共振成像技术研究社会评价威胁对社会困境中决策行为(特别是合作行为)个体差异的神经机制。材料与方法共计60名健康受试者参与本研究,受试者被随机分为威胁组(30名)和非威胁组(30名)。实验前获取受试者照片并告知受试者会有陌生人对此照片进行评价,威胁组获得的社会评价多为负性,非威胁组获得的社会评价多为正性。实验任务分为三个组块,在每个组块,受试者首先会得知社会评价反馈的情况,然后与多人分别完成单次囚徒困境任务。在囚徒困境任务中,受试者需要选择是否与对方进行合作,所获报酬与由选择结果决定。本研究采用受试者在囚徒困境中的合作率作为衡量社会评价威胁对决策行为产生的影响的指标。通过分析工具(a toolbox for data processinganalysis for brain imaging,DPABI)处理采集到的静息态数据,并将合作率分别与静息状态下大脑的局部一致性(regional homogeneity,Re Ho)以及低频振幅(amplitude of low-frequency fluctuation,ALFF)做相关分析。结果右侧眶额叶皮层的Re Ho值、ALFF值与社会评价威胁条件下社会困境中的总合作率以及受到多次威胁后的合作率呈负相关;纹状体的ALFF值与社会评价威胁条件下社会困境中的总合作率以及受到多次威胁后的合作率呈负相关。结论静息状态下眶额叶皮层和纹状体的活动情况与社会评价威胁后社会困境中的合作行为有关。     

动机对反应攻击的调制作用--基于静息态fMRI的个体差异研究

目的采用泰勒范式并结合静息态功能磁共振成像技术研究他人动机对反应攻击调制的个体差异的神经机制。材料与方法共计30名健康男性被试参与本研究。在任务中,被试与4个对手轮流进行竞争反应时比赛,输的人被赢的人惩罚。这4个对手分别设置为:故意的高、低攻击对手和无意的高、低攻击对手。本研究采用被试给故意和无意高攻击对手惩罚强度的差值来量度动机对个体反应攻击的调制效应(动机效应)。使用DPARSF处理采集到的静息态数据,并将动机效应与静息状态下大脑的局部一致性(regional homogeneity,Re Ho)做相关分析。结果右侧颞顶联合区的Re Ho值与动机效应呈正相关;右侧纹状体的Re Ho值与动机效应呈负相关。结论这些数据表明颞顶联合区和纹状体与动机对反应攻击的调制作用有关。     

静息态fMRI评价脑瘫患儿手术前后的脑功能

目的联合静息态功能磁共振成像(resting-state functional MRI,rs-fMRI)中较常用的低频振幅(amplitude of low-frequency fluctuation,ALFF)及局部一致性(regional homogeneity,ReHo)两种分析方法探讨颈总动脉交感神经网剥脱术对单侧痉挛型脑瘫患儿脑功能的影响。材料与方法对21例单侧痉挛型脑瘫患儿手术前1周及手术后14d分别进行常规序列及rs-fMRI检查。利用静息态脑功能数据辅助处理(data processing assistant for resting-state fMRI,DPARSF)软件对图像进行预处理并获取ALFF及ReHo值。采用配对样本t检验比较21例单侧例痉挛型患儿手术前和手术后ALFF及ReHo值差异。结果术后14 d脑瘫患儿患侧大脑半球多个脑区ALFF值和(或)ReHo升高,健侧小脑前叶ALFF值升高(P<0.05);术后14 d脑瘫患儿健侧多个脑区的ALFF值和(或)ReHo降低,患侧额上回ALFF及ReHo值降低(P<0.05)。结论rs-fMRI结果表明,颈总动脉交感神经网剥脱术主要提高单侧痉挛型脑瘫患儿患侧与运动以及认知功能相关脑区区域神经元自发低频振荡活动强度,加强脑区的功能联系。     

Different neural systems adjust motor behavior in response to reward and punishment

Individuals use the outcomes of their actions to adjust future behavior. However, it remains unclear whether the same neural circuits are used to adjust behavior due to rewarding and punishing outcomes. Here we used functional magnetic resonance imaging (fMRI) and a reward-providing reaction time task to investigate the adaptation of a simple motor response following four different outcomes (delivery versus omission and monetary gain versus loss). We found that activation in the thalamus and insula predicted adjustments of motor responses due to outcomes that were cued and delivered, whereas activation in the ventral striatum predicted such adjustments when outcomes were cued but omitted. Further, activation of OFC predicted improvement after all punishing outcomes, independent of whether they were omitted rewards or delivered punishments. Finally, we found that activity in anterior cingulate predicted adjustment after delivered punishments and activity in dorsal striatum predicted adaptation after delivered rewards. Our results provide evidence that different but somewhat overlapping circuits mediate the same behavioral adaptation when it is driven by different incentive outcomes.     

Functional neuroanatomy of different olfactory judgments

Humans routinely make judgments about olfactory stimuli. However, few studies have examined the functional neuroanatomy underlying the cognitive operations involved in such judgments. In order to delineate this functional anatomy, we asked 12 normal subjects to perform different judgments about olfactory stimuli while regional cerebral blood flow (rCBF) was measured with PET. In separate conditions, subjects made judgments about the presence (odor detection), intensity, hedonicity, familiarity, or edibility of different odorants. An auditory task served as a control condition. All five olfactory tasks induced rCBF increases in the right orbitofrontal cortex (OFC), but right OFC activity was highest during familiarity judgments and lowest during the detection task. Left OFC activity increased significantly during hedonic and familiarity judgments, but not during other odor judgments. Left OFC activity was significantly higher during hedonicity judgments than during familiarity or other olfactory judgments. These data demonstrate that aspects of odor processing in the OFC are lateralized depending on the type of olfactory task. They support a model of parallel processing in the left and right OFC in which the relative level of activation depends on whether the judgment involves odor recognition or emotion. Primary visual areas also demonstrated a differential involvement in olfactory processing depending on the type of olfactory task: significant rCBF increases were observed in hedonic and edibility judgments, whereas no significant rCBF increases were found in the other three judgments. These data indicate that judgments of hedonicity and edibility engage circuits involved in visual processing, but detection, intensity, and familiarity judgments do not.     

Neurocircuits underlying cognition-emotion interaction in a social decision making context

Decision making (DM) in the context of others often entails complex cognition-emotion interaction. While the literature suggests that the ventromedial prefrontal cortex (vmPFC), striatum, and amygdala are involved in valuation-based DM and hippocampus in context processing, how these neural mechanisms subserve the integration of cognitive and emotional values in a social context remains unclear. In this study we addressed this gap by systematically manipulating cognition-emotion interaction in a social DM context, when the participants played a card game with a hypothetical opponent in a behavioral study (n=73) and a functional magnetic-resonance-imaging study (n=16). We observed that payoff-based behavioral choices were influenced by emotional values carried by face pictures and identified neurocircuits involved in cognitive valuation, emotional valuation, and concurrent cognition-emotion value integration. Specifically, while the vmPFC, amygdala, and ventral striatum were all involved in both cognitive and emotional domains of valuation, these regions played dissociable roles in social DM. The payoff-dependent responses in vmPFC and amygdala, but not ventral striatum, were moderated by the social context. Furthermore, the vmPFC, but not amygdala, not only encoded the opponent's gains as if self's losses, but also represented a "final common currency" during valuation-based decisions. The extent to which emotional input influenced choices was associated with the functional connectivity between the value-signaling amygdala and value integrating vmPFC, and also with the functional connectivity between the context-setting hippocampus and value-signaling amygdala and ventral striatum. These results identify brain pathways through which emotion shapes subjective values in a social DM context.     

Reduced resting-state functional connectivity between amygdala and orbitofrontal cortex in social anxiety disorder

Social anxiety disorder patients suffer from excessive anxious responses in social interaction leading to avoidance behavior and social impairment. Although the amygdala has a central role in perception and processing of threatening cues, little is known about the involved networks and corresponding dysfunctions in social anxiety. Therefore, this study aims to investigate the functional connectivity network of the amygdala in patients with social anxiety disorder and to identify regions that might influence amygdalar reactivity via modulatory pathways. Ten patients with anxiety disorders (social and/or panic) and 27 healthy controls underwent a facial emotion processing task as well as 6-min functional MRI at resting state. Individual voxel-wise functional connectivity maps were calculated using the amygdala as seed region. Group comparisons were done by random-effects analysis in SPM. Patients exhibited an amygdala hyperactivation during the emotional task and decreased functional coupling of the left amygdala with the medial orbitofrontal cortex and the posterior cingulate cortex/precuneus. The strength of this functional connectivity showed a negative association with the severity of state anxiety. In addition, an exploratory analysis revealed further reduced functional connectivity and a marked functional separation between the medial orbitofrontal and anterior cingulate cortices in the patient group. Our results suggest alterations within the amygdalar functional connectivity network in social anxiety disorder. Combined with the amygdalar hyperactivation our findings corroborate the proposed dysfunction of the fronto-amygdalar inhibition in anxiety disorders and indicate a modulatory influence of the anterior and posterior cingulate cortices on threat perception and processing.     

功能磁共振成像观察复发缓解型多发性硬化患者运动相关脑区的局部一致性

目的采用静息态功能磁共振(rs-fMRI)区域局部一致性(ReHo)技术,观察复发缓解型多发性硬化(RRMS)患者脑局部ReHo值。方法收集19例RRMS患者(RRMS组)与19名年龄、性别相匹配的健康对照者(对照组)行rsfMR和常规MR检查。分别提取两组左、右侧运动相关脑区ReHo值行两样本t检验分析,对RRMS组双侧运动相关脑区ReHo值与患者EDSS评分行相关性分析。结果与正常对照组相比,RRMS患者双侧运动相关脑区ReHo值降低(P<0.05,经AlphaSim校正,体素>20),患者双侧运动相关脑区ReHo值与EDSS评分均呈负相关(右侧:r=-0.819,P<0.05;左侧:r=-0.871,P<0.05)。结论 RRMS患者运动相关脑区神经元活动一致性存在减低改变,这种改变可能是患者运动功障碍形成的相关因素之一。     

Implicit motivational value and salience are processed in distinct areas of orbitofrontal cortex

Recent studies have shown that motivational stimulus information is represented in the brain even in situations where the individual is not actively engaged in stimulus evaluation. However, it has remained unclear whether neural representations of such implicit motivational information reflect the motivational value or motivational salience of stimuli. While motivational values correspond to the desirability of stimuli, motivational salience is related to the arousal elicited by the stimulus. Here we aimed at disentangling the neural representation of both motivational dimensions. In the first part, participants learned the association of face stimuli with monetary reward and punishment. The same face stimuli were presented in a subsequent fMRI experiment, during which participants either performed a gender discrimination task on the faces or an orientation discrimination task on two simultaneously presented bars. Importantly, faces only differed regarding their implicit motivational information as acquired in the previous learning task, as participants neither received monetary reinforcement during the fMRI experiment nor were they asked to explicitly judge their face preferences. We found that neural responses in lateral OFC were modulated by implicit motivational value, whereas the faces' implicit motivational salience was coded in medial OFC. While the value-related responses in lateral OFC decreased over time, the salience-related modulation of medial OFC activity remained stable over the duration of the fMRI experiment. Neural responses to both motivational dimensions were observed independent of whether participants' attention was directed to the faces or to the surrounding bars, suggesting an automatic processing of implicit motivational value and salience. The functional dissociation within the OFC suggests that this region is critically involved in distinct motivation-related processes: In medial OFC, a representation of salient items may be maintained in order to facilitate responses towards behaviourally relevant stimuli in the future; in contrast the temporary value effect in lateral OFC might reflect decreasing stimulus valuation in the absence of explicit motivational stimulus differences.     

基于rs-fMRI技术探讨臭氧水对膝骨性关节炎疼痛患者镇痛作用的中枢机制

目的利用静息态功能磁共振成像(resting state functional magnetic resonance imaging,rs-fMRI)技术探讨臭氧水对慢性疼痛的膝骨性关节炎(knee osteoarthritis,KOA)患者镇痛作用的中枢效应机制,为临床臭氧水治疗KOA提供理论依据。材料与方法将符合纳入标准的18名KOA患者进行臭氧水关节腔冲洗治疗,每周1次,共治疗3次。分别在治疗前、治疗后行疼痛视觉评分(visual analog scale,VAS)和rs-fMRI扫描;采用局部一致性(regional homogeneity,ReHo)的数据分析方法,分析臭氧水治疗后ReHo显著变化的脑区;并将ReHo与VAS评分变化进行Pearson相关性分析。结果臭氧水治疗后,KOA患者的VAS评分显著降低(P=0.000),枕上回(t=3.69)、枕中回、楔叶、角回等脑区不同区域ReHo值增高(t=4.89),中央沟盖(t=-4.19)、颞上回、中央前回等脑区不同区域ReHo值降低(t=-5.45)。相关性分析结果显示臭氧水治疗后,右岛叶(r=-0.657)ReHo变化与VAS变化呈负相关。结论臭氧水可能是通过调节颞叶、顶叶、额叶、枕叶等脑区的功能达到治疗KOA患者疼痛的作用;而岛叶可能是臭氧水镇痛作用的关键脑区。