工作记忆的神经振荡调控：基于神经振荡夹带现象

工作记忆的神经振荡机制研究是当前记忆领域的研究热点之一。那么, 神经振荡仅仅是工作记忆过程的伴随现象, 还是直接参与并调控了工作记忆的加工过程?已有研究发现, 大脑内部的神经振荡活动在外界节律性刺激的驱动下, 逐步与外界刺激节律相位同步化, 这一现象被称为“神经振荡夹带”。重复经颅磁刺激(repetitive Transcranial Magnetic Stimulation, rTMS)和经颅交流电刺激(transcranial Alternating Current Stimulation, tACS)干预研究基于此现象, 对大脑局部脑区施加节律性磁、电刺激, 进而调控工作记忆过程中特定频段的神经振荡活动、跨频段的神经振荡耦合或跨脑区的神经振荡相位同步, 为神经振荡参与工作记忆加工提供较为直接的因果证据。未来研究需考虑从脑网络的角度出发, 调控多个脑区之间的神经振荡活动, 进一步考察神经振荡对工作记忆的影响。此外, 还需注意探索和优化rTMS/tACS调控工作记忆的刺激方案, 并辅以客观的脑电记录, 提高该类研究的有效性和可重复性, 最终达到提高工作记忆能力的目的。     

探究事件相关脑电/脑磁信号中的神经表征模式：基于分类解码和表征相似性分析的方法

探究不同心智活动下的神经表征差异, 是认知神经科学关注的核心问题之一。早期的脑电/脑磁分析方法主要关注组平均后的神经响应水平, 这要求在关注的时间进程上, 各个被试在相同刺激条件下事件相关电位/事件相关磁场的振幅大小和方向、以及地形图分布和极性均要有较高的一致性。近些年来, 研究者们将功能性磁共振成像研究中常用到的两种技术——机器学习中的分类算法(即基于分类的解码)和表征相似性分析——引入到了脑电/脑磁数据分析中。这两种新技术可以克服传统脑电/脑磁数据基于具体电压/磁感应强度波形平均分析的缺点, 具有在个体水平上探究神经表征编码的特点, 为人们探究大脑在不同时间进程上如何对特定的神经表征信息进行动态编码提供了新的思路。两种技术基于不同的方法学原理来抽提个体间一致的脑认知加工机制, 还为脑电/脑磁研究开展跨时域、跨任务、跨模态、跨群体比较不同认知过程中的表征差异提供了更多新颖的途径。我们首先通过与传统的脑电/脑磁分析方法进行比较, 系统性介绍了基于分类的解码和表征相似性分析的原理和操作流程, 之后对两种方法的应用场景进行了梳理, 并在最后对未来可供研究的方向提出了我们的见解。     

认知心理生理学与无创性脑功能成像技术

无创性脑功能成像技术是认知心理生理学研究的重要手段。脑电图、事件相关电位、脑磁图、正电子发射断层摄影术、单光子发射计算机断层摄影术、功能磁共振成像和功能红外线成像等技术通过对人脑的电磁、新陈代谢、血流量、氧消耗、神经元活动等的测量来研究如视觉、注意、记忆、语言等认知活动及其与相关脑机制的相互关系。它们各有优缺点。     

神经元活动的时相同步与脑功能整合

从大脑整合的角度分析心理的神经机制。神经元之间的交互和动态联结而构成神经集合被认为是每一个认知活动的基础。然而这一交互作用的具体性质,即脑整合的机制尚未明确。通过对有关实验结果的分析,认为神经元活动的时相同步可能是脑整合的机制。     

神经振荡影响快速言语识别的时间瓶颈

大脑可以快速地加工信息以应对不断变化的环境,其典型范例之一是快速言语识别。自然言语的瓶颈速率约为8～12音节/秒,与神经振荡的alpha速率相近。此外,已有研究表明alpha振荡可以调控知觉过程的时间分辨率。那么,alpha振荡速率是否影响快速言语识别的时间瓶颈？其作用机制是什么？本研究利用心理物理学方法和认知神经科学方法,从现象和机制两个方面考察alpha振荡如何影响快速言语识别的时间瓶颈。在现象方面,本研究将验证快速言语识别的时间瓶颈与alpha振荡速率的一致性。在机制方面,本研究将研究alpha振荡速率如何影响快速言语识别的行为表现,又如何调控大脑对言语信号的神经加工过程。本研究希望找到快速言语识别的神经机制,从而更深入地理解大脑的快速加工过程,并进一步探讨神经振荡调控大脑时间分辨率的相关机制。     

人类社会认知的神经机制:来自社会脑研究的证据

社会认知是指从环境互动的过程中推测他人意图、情感和思想等内部状态的心理加工过程。社会脑假说认为,包括人类在内的灵长类大脑内肯定存在着一个旨在认识和理解他人表情的神经机制,在社会交往中通过该中枢迅速处理与他人相互作用的各种信息。本文通过回顾社会脑的构成与基本功能,镜像神经元的发现及功能,以及社会脑、镜像神经元对社会认知影响的相关研究,提出了人类社会认知不同于其他物种的三个主要区别。     

镜像神经元系统的研究回顾及展望

镜像神经元系统的发现使得研究者从一个较为统一的神经机制层面了解人类多个层次的社会认知活动。在猕猴大脑F5区发现的镜像神经元可以在抽象的层面上帮助猕猴理解他人行为的意图。利用脑成像技术,研究发现人类的镜像神经元系统能够匹配外界的知觉表征和内在的动作表征从而通过“居身模仿”这一过程来进行模仿、语言理解、理解他人的意图及情绪这些重要的社会认知活动。另外,镜像神经元系统在社会交往中也起着重要作用,最后,就镜像神经元系统在心理理论中的作用、了解自我-他人问题和镜像神经元系统的关系、动机、经验等因素对镜像神经元系统活动的调控等问题对未来的研究方向进行了展望     

触觉-视觉交叉模式工作记忆的研究

目的:探讨触觉-视觉交叉模式工作记忆的大脑神经活动机理.方法:训练11个正常受试者学习交叉模式工作记忆任务,利用Neuroscan EEG系统记录脑电活动,对脑电数据求源分析后,着重考察事件相关脑电成分所处的大脑空间位置.结果发现:在延时过程中的3个主要的脑电成分N40,LPC和LNC的神经活动源分别处于大脑的右侧顶叶,中间后顶叶和前额叶.这提示了交叉模式工作记忆中相继的三个神经认知功能:感知,触觉一视觉模式阃的信息交互,和工作记忆的维持.     

θ频段(4～8Hz)的活动反映了汉语口语产生中音节信息的加工

大脑的神经振荡往往反映了人类的各种认知活动。语言理解的研究发现大脑θ频段的活动与音节的加工密切相关,但目前尚未有研究者探究语言产生过程中大脑特定频段活动与音节加工的联系。我们通过EEG时频分析技术,采用掩蔽启动范式,考察了23名健康被试在图片命名过程中θ频段的活动与音节加工过程的关系。行为结果发现,当启动词和目标图名称之间存在音节相关时,个体的命名反应时快于音节无关的条件,而音素相关条件的命名反应时慢于音素无关条件。时频结果发现,在刺激出现后的270～460ms,音节相关条件下个体θ频段神经振荡的能量显著低于音节无关条件,音素相关与音素无关之间无显著差异。综上,我们认为汉语口语产生中大脑θ频段的活动反映了对音节的加工,从神经振荡指标上为音节是汉语口语词汇产生中音韵编码的单元提供了证据。     

脑内乙酰胆碱与认知活动的关系

脑内细胞外乙酰胆碱（ACh）的变化主要反映胆碱能神经元的活动,皮层和海马等脑区的ACh主要来源于基底前脑胆碱能神经元的纤维投射。应用微透析等技术在体检测清醒、自由活动动物认知过程中脑内乙酰胆碱的含量,可以研究ACh与特定行为反应和认知活动之间的关系。研究发现当机体需要对新刺激进行分析时,在学习与记忆、空间工作记忆、注意、自发运动和探究行为等认知活动中,基底前脑胆碱能神经元被激活,脑内ACh的释放也随之改变。结果提示脑内胆碱能递质系统活动与认知过程密切相关     

品牌消费旅程中消费者的认知心理过程——神经营销学视角

品牌消费旅程通常指的是对于品牌消费服务的多维度(包括认知, 情绪, 感觉, 行为和品牌关系)响应。揭示品牌消费旅程的认知心理过程是目前营销学领域之中研究的重点与热点。在梳理当前神经营销领域内有关功能性核磁共振(fMRI)、事件相关电位(ERP)、事件相关震荡(ERO)的相关研究成果后, 将消费者在品牌消费旅程之中的认知心理进程划分为注意吸引、决策形成、消费体验和品牌忠诚四个阶段, 并系统阐述了每个阶段之中消费者心理进程的神经机制与脑区活动, 进而全面立体地揭示消费心理的全貌。未来研究可以进一步探索不同神经指标在具体营销情境下的表征意义, 并结合超扫描技术进一步解析多个被试间的神经耦合情况。     

情景记忆成功年老化的神经机制

随着年龄的增长, 大部分老年人的情景记忆会出现衰退, 但也会有一部分老年人的情景记忆表现出成功的年老化, 即记忆成绩较好或随增龄的衰退程度较小。脑保持理论、神经去分化理论、认知储备理论以及神经补偿理论分别从不同角度解释了情景记忆成功年老化的神经机制。基于选择性优化与补偿模型对现有理论进行整合, 发现情景记忆成功年老化可能与个体的认知储备水平直接相关：高认知储备的老年人能够对情景记忆相关的脑区和脑网络进行优化且具备更强的神经补偿能力, 因而其脑功能(比如, 神经表征和神经加工通路的特异性)可能会保持地更好。未来研究需要更多地采用纵向设计来考察各理论之间的关系及其影响因素, 从而更好地解释记忆成功年老化的神经机制并为提升老年人的脑与认知健康提供支持。     

Connecting the Dots: A Review of Resting Connectivity MRI Studies in Attention-Deficit/Hyperactivity Disorder

Psychopathology is increasingly viewed from a circuit perspective in which a disorder stems not from circumscribed anomalies in discrete brain regions, but rather from impairments in distributed neural networks. This focus on neural circuitry has rendered resting state functional connectivity MRI (rs-fcMRI) an increasingly important role in the elucidation of pathophysiology including attention-deficit/hyperactivity disorder (ADHD). Unlike many other MRI techniques that focus on the properties of discrete brain regions, rs-fcMRI measures the coherence of neural activity across anatomically disparate brain regions, examining the connectivity and organization of neural circuits. In this review, we explore the methods available to investigators using rs-fcMRI techniques, including a discussion of their relative merits and limitations. We then review findings from extant rs-fcMRI studies of ADHD focusing on neural circuits implicated in the disorder, especially the default mode network, cognitive control network, and cortico-striato-thalamo-cortical loops. We conclude by suggesting future directions that may help advance subsequent rs-fcMRI research in ADHD.     

Social outcomes in childhood brain disorder: a heuristic integration of social neuroscience and developmental psychology

The authors propose a heuristic model of the social outcomes of childhood brain disorder that draws on models and methods from both the emerging field of social cognitive neuroscience and the study of social competence in developmental psychology/psychopathology. The heuristic model characterizes the relationships between social adjustment, peer interactions and relationships, social problem solving and communication, social-affective and cognitive-executive processes, and their neural substrates. The model is illustrated by research on a specific form of childhood brain disorder, traumatic brain injury. The heuristic model may promote research regarding the neural and cognitive-affective substrates of children's social development. It also may engender more precise methods of measuring impairments and disabilities in children with brain disorder and suggest ways to promote their social adaptation.     

Synchronous neural oscillations and cognitive processes

The central problem for cognitive neuroscience is to describe how cognitive processes arise from brain processes. This review summarizes the recent evidence that synchronous neural oscillations reveal much about the origin and nature of cognitive processes such as memory, attention and consciousness. Memory processes are most closely related to theta and gamma rhythms, whereas attention seems closely associated with alpha and gamma rhythms. Conscious awareness may arise from synchronous neural oscillations occurring globally throughout the brain rather than from the locally synchronous oscillations that occur when a sensory area encodes a stimulus. These associations between the dynamics of the brain and cognitive processes indicate progress towards a unified theory of brain and cognition.     

The Implications of Brain Connectivity in the Neuropsychology of Autism

Autism is a neurodevelopmental disorder that has been associated with atypical brain functioning. Functional connectivity MRI (fcMRI) studies examining neural networks in autism have seen an exponential rise over the last decade. Such investigations have led to the characterization of autism as a distributed neural systems disorder. Studies have found widespread cortical underconnectivity, local overconnectivity, and mixed results suggesting disrupted brain connectivity as a potential neural signature of autism. In this review, we summarize the findings of previous fcMRI studies in autism with a detailed examination of their methodology, in order to better understand its potential and to delineate the pitfalls. We also address how a multimodal neuroimaging approach (incorporating different measures of brain connectivity) may help characterize the complex neurobiology of autism at a global level. Finally, we also address the potential of neuroimaging-based markers in assisting neuropsychological assessment of autism. The quest for a neural marker for autism is still ongoing, yet new findings suggest that aberrant brain connectivity may be a promising candidate.     

Neurological knowledge and complex behaviors

Some scholars believe thot Cognitive Science is the attempt to achieve in artificial systems what has already been achieved in the brain. Others, by contrast, argue that the study of ideal adaptive mechanisms could go on without reference to the brain. The author points out that the brain may not be the ideal cognitive device because of biological limitotions on its capacity. Although it may not be ideal, it is still of major interest to cognitive scientists because of the great interest in the human mind, and, in addition, because at this moment the brain is the most important single reservoir of odoptive mechanisms. The paper discusses several areas of neuroscience which are likely to shed light on mechanisms of adaptation. The study of simple nervous systems is likely to reveal important design principles of cognitive devices. The study of complex nervous systems will, of course, exert a major influence. The study of such systems leads to certain general principles concerning the neural circuits involved in complex odoptive behaviors: (1) There exist innate specialized systems for the learning of many specific behaviors that at first might appeor to be purely cultural. (2) There is no evidence for the existence of any all-purpose computer in the brain. (3) There are many surprising dissociations manifested by the specialized systems in the brain, e.g., a special system for recognition of faces as against other visual patterns. (4) The study of the nervous system enables one to formulate more precise mechanisms for the role of emotion in cognitive function.(5) Some human behoviors con probably be understood poorly or not at all if the neural substrate is not considered. (6) The cognitive systems designed for dealing with ottentionol processes may be among the most complex neural structures which underlie behavior. There are certain other properties of brains that should be kept in mind by the cognitive scientists who are studying human behovior: (1) Brains differ from each other in structure, and it is very likely that the strategy for the solution of certain problems differs from person to person. (2) The presence of certain innate cognitive strategies in the brain may prevent that organism from employing other strategies which might be optimal for other problems. (3) Any theory about a particular cognitive strategy will have implications as to the particular mode of breakdown that might be expected after brain lesions. The study of disordered function from brain disease may thus be a valuable way to test certain cognitive theories.     

The Basics of Brain Development

Over the past several decades, significant advances have been made in our understanding of the basic stages and mechanisms of mammalian brain development. Studies elucidating the neurobiology of brain development span the levels of neural organization from the macroanatomic, to the cellular, to the molecular. Together this large body of work provides a picture of brain development as the product of a complex series of dynamic and adaptive processes operating within a highly constrained, genetically organized but constantly changing context. The view of brain development that has emerged from the developmental neurobiology literature presents both challenges and opportunities to psychologists seeking to understand the fundamental processes that underlie social and cognitive development, and the neural systems that mediate them. This chapter is intended to provide an overview of some very basic principles of brain development, drawn from contemporary developmental neurobiology, that may be of use to investigators from a wide range of disciplines.     

第二语言学习与脑可塑性

脑可塑性指人脑会因为环境刺激、认知需求和行为经验而产生功能或结构改变。近10年来的单双语者对比和语言训练研究结果表明, 不论儿童、青年或老年人, 第二语言学习和使用都能改变其脑运行模式并带来相应结构变化, 包括灰质(GM)体积和白质(WM)密度增加, 且长期持续的双语经验还能形成认知优势, 帮助抵制由老化导致的负面认知影响。基于脑可塑性概念及其研究证据, 从双语经验与语言训练两方面, 对比分析了长期和短期第二语言学习引起脑功能或结构变化及其内在机制, 并对未来相关研究进行了展望。     

Stuttering: a dynamic motor control disorder

The purpose of this review is to determine what neural mechanisms may be dysfunctional in stuttering. Three sources of evidence are reviewed. First, studies of dynamic inter-relationships among brain regions during normal speech and in persons who stutter (PWS) suggest that the timing of neural activity in different regions may be abnormal in PWS. Second, the brain lesions associated with acquired stuttering are reviewed. These indicate that in a high percentage of cases, the primary speech and language regions are not affected but lesions involve other structures, such as the basal ganglia, which may modulate the primary speech and language regions. Third, to characterize the motor control disorder in stuttering, similarities and differences from focal dystonias such as spasmodic dysphonia (SD) and Tourette’s syndrome (TS) are reviewed. This review indicates that the central control abnormalities in stuttering are not due to disturbance in one particular brain region but rather a system dysfunction that interferes with rapid and dynamic speech processing for production.

Educational objectives: The reader will be able to describe: (1) the similarities and differences between stuttering and other speech motor control disorders, (2) which brain lesions are most likely to produce acquired stuttering in adults, and (3) what type of brain abnormality most likely underlies stuttering.