心理定势现象的认知神经机制

问题解决活动中的心理定势,是指人们固执地沿用熟悉方案、忽略其他方案的反应倾向。它可能源于人们已经掌握的陈述性知识,也可能源于程序性知识,两类不同来源的心理定势的发生条件和影响效果都不尽相同。然而,过往的研究都没有做出严格区分。本文通过梳理相关研究,描述心理定势现象,解释心理定势是怎么发生的,分析心理定势是在什么条件下发生的、会对心理与行为活动造成什么样的影响,从而评述两种来源的心理定势的认知神经机制,指出尚未解决的科学问题。     

Timing without a timer.

Inferred-process theories propose various internal timing mechanisms to provide discriminative stimuli for temporal control of behavior. Biobehaviorally informed computer simulations indicate that timing may emerge from the action of reinforcement on neural circuits without the need to postulate timers of any sort.     

Thurstone's discriminal processes fifty years later

Four issues are discussed concerning Thurstone's discriminal processes: the distributions governing the representation, the nature of the response decision rules, the relation of the mean representation to physical characteristics of the stimulus, and factors affecting the variance of the representation. A neural schema underlying the representation is proposed which involves samples in time of pulse trains on individual neural fibers, estimators of parameters of the several pulse trains, samples of neural fibers, and an aggregation of the estimates over the sample. The resulting aggregated estimate is the Thurstonian representation. Two estimators of pulse rate, which is monotonic with signal intensity, are timing and counting ratios and two methods of aggregation are averaging and maximizing. These lead to very different predictions in a speed-accuracy experiment; data indicate that both estimators are available and the aggregation is by averaging. Magnitude estimation data are then used both to illustrate an unusual response rule and to study the psychophysical law. In addition, the pattern of variability and correlation of magnitude estimates on successive trials is interpreted in terms of the sample size over which the aggregation takes place. Neural sample size is equated with selective attention, and is an important factor affecting the variability of the representation. It accounts for the magical number seven phenomenon in absolute identification and predicts the impact of nonuniform distributions of intensities on the absolute identification of two frequencies. 1977 Psychometric Society Presidential Address. This work was supported in part by a grant of the National Science Foundation to Harvard University. I wish to express my appreciation to S. Burbeck, D. M. Green, M. Shaw, and B. Wandell for their useful comments on an earlier draft of this paper.     

内外动机对青少年记忆的影响及其神经机制

动机是一切行为的核心, 动机可分为外在和内在动机。青少年时期既是记忆的关键期, 也是动机发展的特殊时期。然而, 目前关于内外动机影响青少年记忆的研究才刚刚起步, 尚不清楚外在和内在动机影响青少年记忆的规律和机制是否一致, 也不清楚二者如何交互影响记忆。本研究将结合认知范式和脑成像技术, 考察外在和内在动机如何分别影响以及交互影响青少年记忆。这将有助于更加全面、深刻理解内外动机影响青少年记忆的独特规律和机制, 为科学提升青少年动机和记忆效果提供研究证据。     

Neural fetal tissue transplants: old and new issues

Abstract. Neural fetal tissue transplantation offers promise as a treatment for devasting neurologic conditions such as Parkinson's disease. Two types of issues arise from this procedure: those associated with the use of fetuses, and those associated with the use of neural tissue. The former issues have been examined in many forums; the latter have not. This paper reviews issues and arguments raised by the use of fetal tissue in general, but focuses on the implications of the use of neural tissue for basic concepts of personnood and personal identity.     

从心理理论的脑机制研究看心理理论与执行功能的关系

心理理论发展与执行功能的关系以及心理理论脑机制的研究是近年来心理理论研究中的一个热点。文章首先对心理理论与执行功能关系的研究现状进行了分析与概括,提出了目前研究中的问题;然后从介绍了心理理论脑机制研究现状,并以此为基础探讨了心理理论与执行功能的关系。     

从认知神经的角度看内隐记忆和外显记忆的分离

当前的一些理论观点认为,内隐记忆和外显记忆依赖于两种不同的记忆系统,它们与大脑的不同区域相联系。该文通过回顾以往相关研究,从神经心理学及神经成像两方面对两种记忆系统的分离现象进行概述：在神经心理学领域发现的证据表明内隐记忆在神经解剖上与外显记忆是分离的;使用fMRI和PET技术,研究者观察到与内隐记忆有关的枕颞区及左下前额区中衰减的神经活动,以及与外显记忆有关的内侧颞区、前额皮层和后内侧顶皮层中增强的活动;使用ERP技术,研究也发现了两种记忆神经系统在时空上的不同特征     

语义知识神经表征的fMRI研究：通道特异性或类别特异性？

在同一实验中同时考虑类别与通道二个因素,并采用典型的语义提取任务应用功能磁共振成像技术探讨了语义知识的神经基础,结果发现不同类型的语义知识的脑激活模式（含左梭形回的激活）无论在范围还是强度上存在很大的相似性;而且,在严格的统计阈值下,不存在通道或是类别特异性激活的脑区。结果提示语义知识的神经表征分布于整个大脑皮层;在提取物体语义知识时都会同时激活该物体的视觉表象。另外,研究观察到的语义提取过程中BA9区的激活进一步证实并扩展了关于“汉语和表音文字在皮层组织上存在重要差异的观点”。     

无意识信息引发的认知控制及其神经机制

对无意识信息引发的认知控制的研究是揭示意识的功能与局限的重要方法和步骤.在无意识认知控制研究中主要采用模式掩蔽和偏对比掩蔽创设无意识条件,使用客观测量方法对意识状态进行测量.作者从无意识抑制控制、无意识冲突控制和无意识错误加工三个方面回顾了近年对无意识认知控制及其神经机制的研究.已有研究从行为和认知神经研究两个方面强有力地证明了无意识认知控制的存在,揭示了其神经机制.这些研究拓展了人们对意识信息广度和深度的认识,也为未来进一步揭示意识的起源等问题奠定了一定的基础.未来的研究可以从无意识认知控制和有意识认知控制的相互转化等方面进行进一步研究.