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自闭症谱系障碍(ASD)是一种心理状况的谱系障碍,其症状是社交及沟通上的广泛性异常、异常局限性的兴趣和高度重复性的刻板行为。包括自闭症、亚斯伯格症候群和待分类的广泛性发展障碍3类。研究主要以事件相关电位和功能性磁共振成像两种技术为线索,通过深入分析ASD患者在面孔识别认知过程中脑的异常变化,探讨其面孔识别障碍的神经机制问题。研究表明,ASD患者面孔识别能力的损伤主要与N170、N300、P400和Nc等ERPs成份异常及梭状回面孔区和杏仁核的低激活有关。研究推论ASD患者面孔识别障碍是多个异常脑区联合作用的结果,且主要受异常脑区的数量和损伤程度的影响。 相似文献
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后悔是基于对不利或相对不利行为结果的反事实思维诱发的一种复杂的负性社会情绪,对我们日常生活的决策和身心健康具有重大的影响。与失望情绪相比,后悔在现象学、产生条件以及评价方式等方面具有明显的差异。后悔不仅会受到个体的行为方式、人格特征、归因等因素的影响,而且还会受到结果信息属性的影响。后悔的预期和体验涉及的功能性脑区主要包括:眶额皮层、扣带前回、海马、杏仁核。研究后悔的实验方法和技术手段有待于进一步拓展,后悔的认知机制和神经基础还有待于进一步探讨和完善 相似文献
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发展性协调障碍是一种特殊的发育障碍, 它的一个显著特征是动作协调困难, 这种障碍影响着5%~8%学龄儿童的学业成绩和日常生活。发展性协调障碍常常与其他类型的学习困难并存。发展性协调障碍的病因非常复杂, 这种障碍与一定程度的视觉空间认知能力受损有关, 早期精细运动技能发育与脑神经发育进程可能存在时间的重合。近年来, 研究者们试图探索影响发展性协调障碍的神经基础, 并先后提出不同的神经关联假说。这些理论假说主要涉及到小脑、顶叶、胼胝体、基底神经节和大脑白质等脑区。本文全面回顾了该领域研究的最新进展, 并提出未来研究应该关注的方向与问题。 相似文献
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拖延是指尽管预见到拖延会带来不利后果, 人们仍自愿推迟开始或完成某一计划好的任务。研究表明, 不同文化背景下有15%~20%的成年人存在慢性拖延, 超过70%的学生承认自己存在学业拖延, 部分学生还会形成特质性拖延。严重的拖延不仅影响人们的学业、工作和生活, 甚至还会危害到人们的身心健康。鉴于目前对于拖延产生的核心机制、形成的关键期以及发展认知神经机制还不是很清楚, 本项目拟从拖延的时间决策理论出发, 首先系统探明拖延决策的核心机制, 尤其是远期价值评估、延迟折扣和自我控制能力等在拖延决策过程中的认知加工机制和神经基础; 其次结合行为-环境变量-脑的多模态数据, 从发展角度探究拖延形成的关键期(敏感期)、影响因素以及发展认知神经机制; 最后从行为干预和脑的可塑性角度出发, 试图制定各关键年龄阶段拖延预防与干预的临床方案。本研究的开展对于把握拖延形成的认知机制、神经基础及其发展规律具有重要的科学价值, 对于拖延行为的预防和干预也具有直接的现实意义。 相似文献
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拖延行为常常阻碍个人、企业和政府按时完成既定任务,妨害了人们的工作、学业以及疾病防治等方方面面。自我控制是自主减少拖延行为的主要能力,但却是一种相对有限的认知资源。探明自我控制的作用机制有助于更高效地减少拖延行为。然而,由于缺乏合适的认知机制理论和脑成像实验范式,国内外研究多从现象层面探索自我控制、拖延行为和神经指标之间的关系。研究团队提出的“时间决策模型”通过揭示人们如何做出拖延决策,为认知机制的研究和脑成像实验范式的设计提供了理论支持。基于时间决策模型中“现在做还是以后做”的决策机制,本项目拟:(1)结合横向和纵向研究,考察自我控制作用的认知机制及其稳定性;(2)开发拖延的脑成像实验范式,结合多模态MRI技术,揭示自我控制减少拖延决策的神经基础;(3)利用神经刺激技术,考察“基于自我控制脑区的神经干预”的效果及作用机制。研究成果有望为拖延行为提供更加综合的理论框架和新的干预方案。 相似文献
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Grapheme–color synesthesia is a neurological phenomenon where visual perception of letters and numbers stimulates perception of a specific color. Grapheme–color correspondences have been shown to be systematically associated with grapheme properties, including visual shape difference, ordinality, and frequency. However, the contributions of grapheme factors differ across individuals. In this study, we applied multilevel analysis to test whether individual differences in regularities of grapheme–color associations could be explained by individual styles of processing grapheme properties. These processing styles are reflected by the type of synesthetic experience. Specifically, we hypothesized that processing focusing on shape differences would be associated with projector synesthetes, while processing focusing on ordinality or familiarity would be associated with associator synesthetes. The analysis revealed that ordinality and familiarity factors were expressed more strongly among associators than among projectors. This finding suggests that grapheme–color associations are partly determined by the type of synesthetic experience. 相似文献
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大脑梭状回中部被认为是视觉词形加工区(Visual Word Form Area, VWFA)。近年来的研究对VWFA的功能提出了质疑, 研究者开始关注VWFA作为复杂阅读网络的一部分与其它脑区的动态联结机制, 主要集中在三个方面:一是梭状回中部对于视觉词形选择性敏感的本质; 二是它在词汇阅读的神经网络中的作用; 最后是语言经验对于VWFA认知神经功能的塑造作用。结合以上研究的最新进展, 文中指明从动态神经网络的角度揭示大脑功能成为今后认知神经科学研究的最新取向。 相似文献
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与个体做出错误反应相伴的错误相关ERP成分叫错误相关负波 (error-related negativity, ERN),当前冲突监控理论、表征失匹配理论和强化学习理论从不同的角度对ERN的神经机制进行解释,各理论间并非完全相互排斥。目前大部分研究认为ERN定位于扣带回,部分研究则出现其它脑区的激活,然而,扣带回与其它脑区存在复杂的神经功能联系,ERN 电位很可能是多个脑区电活动在头颅的综合表现,而非某一脑区的单独表现。ERN的神经机制受到实验任务、被试年龄及其意识水平等因素的影响。未来要推动实验室研究走向临床应用,发现与诊断脑电波异常的病人和毒品易复吸人群。 相似文献
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The nature of obsessions has led researchers to try to determine if the main problem in obsessive-compulsive disorder (OCD) is impaired inhibitory control. Previous studies report that the effort to suppress is one of the factors that increase the frequency of obsessive thoughts. Based on these results and those of the present study that suggest inferior parietal lobe (IPL) abnormality in OCD and findings of a recent study that reported the importance of the right posterior parietal cortex in cognitive control of a simple mental image, the present cognitive control paradigm study aimed to determine whether there is a difference in brain dynamics between OCD patients and non-obsessive controls while performing tasks that necessitate cognitive control of a simple mental image, and whether the right posterior parietal region is one of the regions in which a difference in activity between the OCD patients and controls would be observed. Functional brain imaging was performed while the participants attempted to suppress, imagine, or manipulate a mental image. The general linear model showed that there was a main effect of group and main effect of task. Accordingly, in all contrasts (suppression minus free-imagination, erasing minus free-imagination, and imagination minus free-imagination), the right IPL, right posterior cingulate cortex, and right superior frontal gyrus activity were lower in the OCD patients than in the healthy controls. These results and the observed correlations between activity levels, and symptom and subjective performance scores are discussed. In conclusion, the results of the present study and those of previous studies suggest that the main problem in OCD might be difficulty activating the right frontoparietal networks during tasks that require cognitive control, which might result in the intrusiveness of obsessive thoughts. 相似文献
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The neuropsychological phenomenon of blindsight has been taken to suggest that the primary visual cortex (V1) plays a unique role in visual awareness, and that extrastriate activation needs to be fed back to V1 in order for the content of that activation to be consciously perceived. The aim of this review is to evaluate this theoretical framework and to revisit its key tenets. Firstly, is blindsight truly a dissociation of awareness and visual detection? Secondly, is there sufficient evidence to rule out the possibility that the loss of awareness resulting from a V1 lesion simply reflects reduced extrastriate responsiveness, rather than a unique role of V1 in conscious experience? Evaluation of these arguments and the empirical evidence leads to the conclusion that the loss of phenomenal awareness in blindsight may not be due to feedback activity in V1 being the hallmark awareness. On the basis of existing literature, an alternative explanation of blindsight is proposed. In this view, visual awareness is a “global” cognitive function as its hallmark is the availability of information to a large number of perceptual and cognitive systems; this requires inter-areal long-range synchronous oscillatory activity. For these oscillations to arise, a specific temporal profile of neuronal activity is required, which is established through recurrent feedback activity involving V1 and the extrastriate cortex. When V1 is lesioned, the loss of recurrent activity prevents inter-areal networks on the basis of oscillatory activity. However, as limited amount of input can reach extrastriate cortex and some extrastriate neuronal selectivity is preserved, computations involving comparison of neural firing rates within a cortical area remain possible. This enables “local” read-out from specific brain regions, allowing for the detection and discrimination of basic visual attributes. Thus blindsight is blind due to lack of “global” long-range synchrony, and it functions via “local” neural readout from extrastriate areas. 相似文献