Nicotinic cholinergic synaptic mechanisms in the ventral tegmental area contribute to nicotine addiction

Tobacco use is a major health problem that is estimated to cause 4 million deaths a year worldwide. Nicotine is the main addictive component of tobacco. It acts as an agonist to activate and desensitize nicotinic acetylcholine receptors (nAChRs). A component of nicotine's addictive power is attributable to actions on the mesolimbic dopaminergic system, which serves a fundamental role in the acquisition of behaviors that are inappropriately reinforced by addictive drugs. Here we show that nicotine, in the same concentration and time ranges as obtained from tobacco, has three main actions that regulate the activity of midbrain dopamine (DA) neurons. Nicotine first activates and then desensitizes nAChRs on the DA neurons. This process directly excites the DA neurons for a short period of time before the nAChRs desensitize. Nicotine also enhances glutamatergic excitation and decreases GABAergic inhibition onto DA neurons. These events increase the probability for synaptic plasticity, such as long-term potentiation. The short-lived direct excitation of the DA neurons coupled with the enhanced glutamatergic afferent activity provides the presynaptic and postsynaptic coincidence necessary to initiate synaptic potentiation. In total, these synaptic events lead to a relatively long-lasting heightened activity of midbrain DA neurons. Consistent with other summarized studies, this work indicates that the synaptic changes normally associated with learning and memory can be influenced and commandeered during the nicotine addiction process.     

Prosodic phrasing and attachment preferences

The attachment of a relative clause (RC) has been found to differ across languages when its head noun is a complex NP. One attempt to explain the attachment differences is the Implicit Prosody Hypothesis (IPH) proposed by Fodor (1998, 2002). The goal of this paper is to show how the default phrasing of a sentence (explicit prosody), defined phonologically, differs across seven languages (English, Greek, Spanish, French, Farsi, Japanese, and Korean), and how the prosodic phrasing of a sentence in each language, both default and nondefault, matches the interpretation of RC attachment by individual speakers. Observed tendencies show that there is a direct relationship between the prosodic phrasing and the interpretation of RC attachment, strongly supporting the IPH. In addition, the paper discusses the status of default phrasing and the factors affecting the default phrasing, including rhythmic and syntactic factors and their interactions.     

Connectedness and part-relation integration in shape category learning

We investigated the role of connectedness in the use of part-relation conjunctions for object category learning. Participants learned categories of two-part objects defined by the shape of one part and its location relative to the other (part-relation conjunctions). The topological relationship between the parts (connected, separated, or embedded) varied between participants but was invariant for any given participant. In Experiment 1, category learning was faster and more accurate when an object’s parts were connected than when they were either separated or embedded. Subsequent experiments showed that this effect is not due to conscious strategies, differences in the salience of the individual attributes, or differences in the integrality/separability of dimensions across stimuli. The results suggest that connectedness affects the integration of parts with their relations in object category learning.     

焦虑对重量感知判断的影响

行动经济理论认为个体对物理环境的感知与其具备的资源有关,而焦虑与资源不足有关。基于此,本研究通过3个实验来探讨3种不同性质的焦虑对重量感知判断的影响。实验1通过身体姿势诱发焦虑,结果发现同放松的身体姿势相比,焦虑的身体姿势能诱发出焦虑且此姿势下个体会认为背包的重量更重。实验2通过具有压力性的外部任务诱发焦虑,结果显示同奇偶判断任务相比,心算任务能诱发出明显的焦虑且此任务下个体将背包的重量判断为更重。实验3探讨特质焦虑的影响,结果发现高特质焦虑个体同低特质焦虑者相比会认为背包的重量更重。本研究表明焦虑会影响个体对物体物理属性的感知。     

The effect of the physical versus mental presence of a high-powered person on consumers' healthy food choices

Consumers make distinct food choices when they see versus when they think about a powerful person. This research identifies two scenarios involving the presence of a high-powered other, physical presence versus mental presence, and examines the effect of the physical and mental presence of a high-powered other on consumers' healthy food choices. Conducting six experiments, we show that the physical presence of a high-powered other increases one's self-enhancement motivation and leads to healthier food choices, while the mental presence of a high-powered other increases one's perceived constraints and leads to unhealthy food choices. We also find that interpersonal closeness moderates the positive effect of the physical presence of a high-powered other on healthy food choices but does not moderate the negative effect of the mental presence of a high-powered other on healthy food choices.     

体悟:道德知行转化的基础

道德主体的知而不行是当今中国道德建设面临的症结之一。本文从知这一环节入手,认为当主体参与道德知识的生产,即从体悟中获得道德认识时,这种知对行最具影响力。体悟是道德知行转化的基础,它不是脱离实践的内求静悟,而是个体理性、情感和实践的有机结合,它重视亲身经验但不排斥他人经验。     

社会认同对抑郁的影响及其理论解释

社会认同作为个体在群际和内群体层面的社会联结,总体上对抑郁产生了积极影响,表现为认同程度、认同重要性、认同群体数量以及认同变化的影响等4个方面。现有研究从需求、认知和行为层面探讨了社会认同影响抑郁的中介因素,并检验了身份认同动机和消极群体评价两个调节因素。社会认同视角下的4种理论分别从社会医治、心理资源、认同变化以及认同层次等不同角度解释了社会认同影响抑郁的心理机制。未来应厘清社会认同对抑郁的深层影响机制,重视社会认同影响抑郁的调节因素,及建构社会认同影响抑郁的能动-共生模型。     

提取干扰对不同类型内隐记忆的影响

以往研究关于提取阶段的干扰是否会影响内隐记忆存在着异义, 其中一个重要因素可能源于所采用的内隐记忆测验类型的差异。本研究采用学习-测验范式, 通过4个实验, 分别考察了提取干扰对识别式知觉内隐测验、识别式概念内隐测验、产生式知觉内隐测验和产生式概念内隐测验的影响, 以期对提取干扰和内隐记忆之间的关系有着更全面的了解。结果表明: (1)词汇判断任务(识别式知觉)和语义分类任务(识别式概念)的启动效应在提取干扰下消失了, (2)而产生式词汇判断任务(产生式知觉)和产生式语义分类任务(产生式概念)在提取干扰下仍发现了明显的启动效应, 但与无干扰条件相比, 启动效应量也有着明显的减少。由此可见, 不同类型的内隐记忆都会受到提取干扰的影响, 相比于产生式启动, 识别式启动更容易受到提取干扰的破坏。     

社会行为的效价信息对注意捕获的影响：基于帮助和阻碍行为的探讨

采用学习-测验两任务范式, 通过3项实验探讨了社会行为的效价信息对注意捕获的影响。在学习阶段, 被试观看具有积极效价的帮助行为(某智能体帮助另一智能体爬山)和消极效价的阻碍行为(某智能体阻碍另一智能体爬山), 以及与各自运动特性匹配的无社会交互行为, 其目的为建立不同智能体颜色与社会行为效价信息的联结关系。在测验阶段, 则分别检验社会行为中的施动方(帮助者和阻碍者)颜色和受动方(被帮助者和被阻碍者)颜色的注意捕获效应。结果发现, 消极社会行为中施动方颜色和受动方颜色均更容易捕获注意, 而积极社会行为效价信息并没有改变联结特征值的注意捕获效应; 且相比于受动方, 与消极社会行为效价建立联结的施动方颜色的注意捕获效应更强。该结果提示, 存在消极社会行为效价驱动的注意捕获, 且消极的效价信息与卷入社会行为所有个体的特征建立联结, 但该联结中施动方物理特征具有更高的注意优先性。这一发现暗示, 声誉信息与对社会交互行为的整体表征可能综合作用于对社会交互事件的注意选择。