大脑电刺激在听觉语言加工研究中的应用

大脑电刺激是历史悠久但近年来才广泛应用在人类被试上的实验技术。通过对颅内刺激位点进行电刺激, 并分析引发的暂时性行为功能变化和记录位点的电位活动, 大脑电刺激技术可以揭示认知加工过程中脑区内的功能作用与脑区间的有效连接。通过对听觉语言加工过程相关的丘脑、听觉皮层、高级语言皮层进行电刺激, 现有研究发现了各个脑区的不同功能特点以及不同脑区间的信息传递机制, 为进一步探索听觉语言加工的神经机制提供了新的视角。     

比喻性语言加工的脑机制

早期观点认为比喻性语言加工主要依赖右脑, 随着研究的深入, 右脑假说受到许多研究结果的挑战, 左脑参与比喻性语言的加工。同时, 左右脑语言区发挥各自不同的作用, 新的研究证实, 前额前部皮层同样参与比喻性语言的加工。比喻性语言的理解需要左右半球及前额皮层的共同激活, 同时对其加工还依赖左右半球的联合作用, 比喻性语言理解神经网络的建立需要新证据。     

数字加工的脑功能成像研究进展及其皮层定位

数字加工是人类最重要的认知功能之一。当前的脑功能成像研究有助于对数字加工与皮层之间的联系进行更精确的定位。基于对上世纪80年代来有关数字加工脑功能成像研究的主要成果的回顾,尤其是一些重要区域,如双侧顶叶与前额叶等在数字加工中的地位与作用,以及不同脑区之间的关系进行了探讨,并对一个广泛运用的数字加工神经机制模型进行了简要评述。在此基础上,对数字加工的皮层定位问题进行了简要的总结。     

弥散张量成像在语言认知神经科学研究中的应用

人类的语言功能不仅仅基于以额叶、颞叶为代表的语言脑区灰质皮层的激活, 更重要的是基于这些脑区之间白质纤维束的连接。随着各种脑成像技术的逐渐成熟, 基于核磁共振的弥散张量成像技术在语言认知领域展现出越来越重要的作用。弥散张量成像在语言认知研究上的应用, 可以将其与行为测查、功能定位成像、功能连接、全脑网络等多种分析方法结合来共同研究语言认知, 进而从脑结构的角度来探究语言与脑的关系。     

药物成瘾者决策缺陷的特征、机制及干预

药物成瘾者存在决策缺陷, 并表现出冲动性、风险寻求、奖赏失调、躯体内感信号缺失等特征。神经影像学研究表明药物滥用导致成瘾者背外侧前额皮层、前扣带回、眶额叶皮层、腹内侧前额皮层、杏仁核、脑岛等脑区受损, 这些损伤是引发其决策缺陷的主要原因。认知训练有利于提高个体的决策能力, 如目标管理训练和正念冥想等可以增强个体工作记忆、促进自我觉察和以目标为导向的行为; 而非侵入性脑刺激则可以直接改变与成瘾者决策相关脑区的激活状态, 从而提升与决策相关的认知功能。总体而言, 未来认知训练和非侵入性脑刺激在成瘾干预方面仍有广阔的拓展空间。     

双语脑的研究:不同的语言是否有不同的皮层机制?

随着认知神经科学技术的发展,研究者对“不同语言是否有不同的大脑皮层机制?”这个问题的研究也进一步深入。一系列的神经心理学和脑成像研究表明,语言获得的时问、流利程度、获得方式等都可能成为影响语言的皮层机制的因素。     

言语学习引起的脑功能和结构变化

文章系统介绍了言语学习引起的脑功能和结构可塑性变化研究的最新进展,例如：第二语言的词汇——语义学习引起的脑功能变化主要受熟练程度的影响,而句法学习引起的脑功能变化主要受获得年龄的影响;实验室言语训练可以引起语言加工相关区域激活增强或减弱,以及出现新的激活区域;第二语言学习导致了左侧顶下皮层灰质密度增加。此外,文章还总结了言语学习的脑成像研究中常用的实验范式,并提出了有待于进一步解决的关键问题     

刻板印象的认知神经机制

刻板印象是大脑对社会信息的一种自动的类别化加工过程。近期脑成像的研究表明, 刻板印象的注意编码、语义表征以及抑制控制等认知成分可以分别通过相应的ERP成分表现出来; 而基于ERP源定位以及fMRI的研究表明, 杏仁核、前扣带回、大脑前额皮层以及外侧顶叶皮层附近的颞顶联结区可能参与到了它们的认知加工。最后结合已有的研究, 提出了刻板印象可能的认知通道, 并简要分析了当前研究的不足与今后的发展方向。     

基于双加工理论解释下信念偏差效应的神经机制

信念偏差效应是指人们已有的知识信念对逻辑推理的影响现象.对此,双加工理论认为这是由于信念偏向系统和逻辑分析系统之间的冲突所导致的.近年来,该理论得到来自认知神经科学证据的有力支持:一方面,基于功能磁共振成像(fMRI)、近红外光谱(NIRS)以及重复性经颅磁刺激(rTMS)等技术的研究从不同角度证实右侧前额皮层与信念偏差抑制有关;另一方面,基于脑电(ERP)的研究表明,晚期正成分和晚期负成分可能参与了不同推理类型下信念偏差效应的认知加工.未来的研究可以从工作记忆、不同加工阶段、推理前提本身可信度、实验分析、实验材料生态学效度以及思维训练等方面对信念偏差效应作进一步探索.     

前额皮层肾上腺素能受体在工作记忆中的作用

前额皮层去甲肾上腺素能神经支配主要来自脑干蓝斑核。前额皮层存在不同类型的肾上腺素能受体。其中突触后α2及β2肾上腺素能受体的激活提高工作记忆;α1及β1肾上腺素能受体的激活损害工作记忆。不同受体是通过激活不同的信号通路发挥对工作记忆的调节作用。来自人类被试的研究结果与对动物的研究结果之间尚存在不一致。了解前额皮层不同肾上腺素受体的作用为开发治疗与前额皮层功能失调相关疾病的药物提供了新的方向。     

前额叶损害对个体一般智力、认知策略与自我监控能力影响的研究

本研究随机挑选了15名因外伤而造成的前额叶损害者和15名正常成人,采用韦氏成人智力量表和自编的图片分类作业,考查了他们在一般智力、认知策略与自我监控能力方面的差异,研究结果表明:(1)前额叶损害对个体的一般智力产生显著的影响,但是其智力仍然处于正常范围,可见智力的脑结构范围极为广泛,智力是一个具有多重性的系统。(2)前额叶损害者对无关刺激的抑制,对有效信息的提取与加工放大的心理活动受到极大影响,认知策略转换能力明显低于正常人,表现出了明显的认知不随意性,额叶可能更多的与个体的计划、认知策略选择、自我监控密切相关;(3)前额叶损害者对具体概念与抽象概念的自我监控能力表现出了不同的影响,对前者的损害显著大于后者,这表明个体依据具体概念进行的形象思维与凭借抽象概念进行的逻辑思维有不同的脑机制。     

语言的群体间偏差研究

个体在用语言来描述他人的行为时,会因为描述对象的群体种类不同而有偏差,具体表现为在描述群体内成员的积极行为和群体外成员的负向行为时,会使用较高抽象水平的词;在描述群体外成员的积极行为和群体内成员的负向行为时,会使用较低抽象水平的词。这种抽象水平的差异由语言范畴模型来具体表明。Maass等人把这种描述上的偏差命名为语言的群体间偏差。并认为在这一现象下有两种机制：动机机制和认知机制,研究表明认知机制能解释大部分语言的群体间偏差现象,而动机机制会在群体内形象受到威胁时发挥作用。     

Cognition Without Control: When a Little Frontal Lobe Goes a Long Way

ABSTRACT— The prefrontal cortex is crucial for the ability to regulate thought and control behavior. The development of the human cerebral cortex is characterized by an extended period of maturation during which young children exhibit marked deficits in cognitive control. We contend that prolonged prefrontal immaturity is, on balance, advantageous and that the positive consequences of this developmental trajectory outweigh the negative. Particularly, we argue that cognitive control impedes convention learning and that delayed prefrontal maturation is a necessary adaptation for human learning of social and linguistic conventions. We conclude with a discussion of recent observations that are relevant to this claim of evolutionary trade-offs in a wide range of research areas, including attention-deficit hyperactivity disorder, autism spectrum disorders, creativity, and sleep.     

认知重评和表达抑制情绪调节策略的脑网络分析：来自EEG和ERP的证据

本文旨在对认知重评和表达抑制两种常用情绪调节策略的自发脑网络特征及认知神经活动进行深入探讨。研究采集36名在校大学生的静息态和任务态脑电数据, 经过源定位和图论分析发现节点效率与两种情绪调节显著相关的脑区, 以及脑区之间的功能连接。研究结果表明, 在使用认知重评进行情绪调节时会激活前额叶皮质、前扣带回、顶叶、海马旁回和枕叶等多个脑区, 在使用表达抑制进行情绪调节时会激活前额叶皮质、顶叶、海马旁回、枕叶、颞叶和脑岛等多个脑区。因此, 这些脑区的节点效率或功能连接强度可能成为评估个体使用认知重评和表达抑制调节情绪效果的指标。     

Linguistic and cognitive prominence in anaphor resolution: topic,contrastive focus and pronouns

This paper examines the role that linguistic and cognitive prominence play in the resolution of anaphor–antecedent relationships. In two experiments, we found that pronouns are immediately sensitive to the cognitive prominence of potential antecedents when other antecedent selection cues are uninformative. In experiment 1, results suggest that despite their theoretical dissimilarities, topic and contrastive focus both serve to enhance cognitive prominence. Results from experiment 2 suggest that the contrastive prosody appropriate for focus constructions may also play an important role in enhancing cognitive prominence. Thus different types of linguistic prominence (topic, contrastive focus) appear to have the common effect of increasing the cognitive prominence of the discourse referent. For pronouns with two possible antecedents, the cognitive prominence of an antecedent aids in anaphor resolution, immediately biasing selection towards the more prominent (and ultimately preferred) antecedent.

Upper processing stages of the perception-action cycle

The neural substrate for behavioral, cognitive and linguistic actions is hierarchically organized in the cortex of the frontal lobe. In their methodologically impeccable study, Koechlin et al. reveal the neural dynamics of the frontal hierarchy in behavioral action. Progressively higher areas control the performance of actions requiring the integration of progressively more complex and temporally dispersed information. The study substantiates the crucial role of the prefrontal cortex in the temporal organization of behavior.     

Inhibition and the right inferior frontal cortex

It is controversial whether different cognitive functions can be mapped to discrete regions of the prefrontal cortex (PFC). The localisationist tradition has associated one cognitive function - inhibition - by turns with dorsolateral prefrontal cortex (DLPFC), inferior frontal cortex (IFC), or orbital frontal cortex (OFC). Inhibition is postulated to be a mechanism by which PFC exerts its effects on subcortical and posterior-cortical regions to implement executive control. We review evidence concerning inhibition of responses and task-sets. Whereas neuroimaging implicates diverse PFC foci, advances in human lesion-mapping support the functional localization of such inhibition to right IFC alone. Future research should investigate the generality of this proposed inhibitory function to other task domains, and its interaction within a wider network.     

Linguistic factors in conditional reasoning

An experiment is reported which demonstrates the influence of three cognitive variables on adults' abilities to reason with conditional arguments embedded in either causal-temporal or class inclusion content. The three variables are the linguistic form of the conditional rule, the principle of conditional reasoning, and the order of the components in the conditional rule. The results showed considerable similarity in the effects of these factors for the two types of concrete content, but some interesting differences were found. The findings are discussed in relation to the results of recent investigations which involved abstract content and/or other deductive reasoning paradigms.     

Updating working memory in aircraft noise and speech noise causes different fMRI activations

The present study used fMRI/BOLD neuroimaging to investigate how visual‐verbal working memory is updated when exposed to three different background‐noise conditions: speech noise, aircraft noise and silence. The number‐updating task that was used can distinguish between “substitution processes,” which involve adding new items to the working memory representation and suppressing old items, and “exclusion processes,” which involve rejecting new items and maintaining an intact memory set. The current findings supported the findings of a previous study by showing that substitution activated the dorsolateral prefrontal cortex, the posterior medial frontal cortex and the parietal lobes, whereas exclusion activated the anterior medial frontal cortex. Moreover, the prefrontal cortex was activated more by substitution processes when exposed to background speech than when exposed to aircraft noise. These results indicate that (a) the prefrontal cortex plays a special role when task‐irrelevant materials should be denied access to working memory and (b) that, when compensating for different types of noise, either different cognitive mechanisms are involved or those cognitive mechanisms that are involved are involved to different degrees.     

Shared language: overlap and segregation of the neuronal infrastructure for speaking and listening revealed by functional MRI

Whether the brain's speech-production system is also involved in speech comprehension is a topic of much debate. Research has focused on whether motor areas are involved in listening, but overlap between speaking and listening might occur not only at primary sensory and motor levels, but also at linguistic levels (where semantic, lexical, and syntactic processes occur). Using functional MRI adaptation during speech comprehension and production, we found that the brain areas involved in semantic, lexical, and syntactic processing are mostly the same for speaking and for listening. Effects of primary processing load (indicative of sensory and motor processes) overlapped in auditory cortex and left inferior frontal cortex, but not in motor cortex, where processing load affected activity only in speaking. These results indicate that the linguistic parts of the language system are used for both speaking and listening, but that the motor system does not seem to provide a crucial contribution to listening.