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.     

Semantic short-term memory and its role in sentence processing: a replication

Previous studies have shown that an aphasic patient (AB) with a semantic short-term memory deficit (STM) had difficulties comprehending and producing sentences with structures that demanded the simultaneous retention of several individual word meanings (Martin & Freedman, 2001a, 2001b; Martin & Romani, 1994; Martin, Shelton, & Yaffee, 1994). The present study provides a replication of these findings with an additional case (ML) who shows a striking dissociation between preserved semantic knowledge and disrupted semantic STM. ML performed poorly on comprehension tasks for sentences that required the retention of single word meanings across several intervening words. In contrast, he did not show an effect of intervening words on processing grammatical relations. ML had difficulty producing adjective-noun phrases, though able to produce the individual nouns and adjectives. These findings support the contention that there is a semantic retention capacity, involved in both comprehension and production, that is separate from semantic knowledge representations.     

疾病的进化论解释：——读《我们为什么生病》

现代医学重在对疾病的近因研究,而疾病的进化史原因,像机体设计上的缺陷,遗传基因与新环境因素的冲突,进化过程中病原同宿主的竞争等,却几乎完全被忽视。事实上,人类机体在漫长的进化过程中,每获得一种益处,几乎都要付出相应的代价,这就是相关的疾病。达尔文医学的新科学,这部全新视野的著作,全面地向人们展示了疾病的进化论解释,并正在创造其学术范式迥然不同的医学科学新领域。     

大脑半球损害病人的汉字抄写研究

对３７例左、右半球病变者进行汉字抄写等测查。结果发现：１．大脑半球病变影响汉字抄写,但左和右半球病变者、皮层和皮层下病变者、失语和非失语病人的汉字抄写成绩无明显差异;２．无论有无失语,抄写与听写都无相关;与画图的关系取决于文化背景,即文化水平低者（无读写能力）汉字抄写与临摹画图高度相关,并受半测空间疏忽影响,而有读写能力者汉字抄写不受以上因素影响。由此推测：不同的汉字书写方式有着不同的神经机制;无汉字读写能力者抄写过程主要与右脑有关,而有读写能力者汉字抄写时双脑并用。     

中国人眼光谱相对视亮度函数的研究——Ⅳ.亮度级对光谱相对视亮度的影响

本研究主要采用闪烁光度法得到四个亮度级上的相对视亮度曲线。以此为基准进而又作出了相应亮度级上最小可觉明度差别阈限曲线。所得结果表明随亮度级增高,光谱相对视亮度发生变化:在可见光谱中段,保持不变,两端降低。     

Emotional labour strategies and job burnout: A meta-analysis of Chinese employees

Emotional labour strategies have a significant impact on job burnout. However, current research results are controversial and unclear. A meta-analysis was conducted to explore the relationship between emotional labour strategies (surface acting and deep acting) and job burnout. A total of 84 empirical studies that included 28,242 participants were selected. The meta-analysis of the relationships between job burnout and surface acting and deep acting included 84 and 75 independent samples respectively. The results show that surface acting had a positive association (r = 0.25) with job burnout, whereas deep acting (r = −0.27) had a negative association with job burnout. Occupational types and measures of emotional labour strategies moderated the relationship between emotional labour strategies and job burnout, but this relationship was not moderated by measures of job burnout.     

Heterospecific eavesdropping on disturbance cues of a treefrog

Animal Cognition - Alarm signals and cues are crucial to animal survival and vary greatly across species. Eavesdropping on heterospecific alarm signals and cues can provide eavesdroppers with...     

时间透视的自我整合:I.心理结构方式的投射测验

用画圆测验和完成句子测验,配合时间标定作业,对２０１名大学生被试的时间透视特点作了探讨,结果发现,在时间透视的广度、方向及关联性等方面,高自我认同组被试有着更大的现有广度,更积极而远景开放的未来取向,以及更强的时间整合;低自我认同组则是过去广度更大,其时间分裂及未来中断的现象理易发生。这些结果初步揭示了建立在时间体验与自我概念的整合基础上的时间透视的心理结构方式。     

时间透视的自我整合:Ⅱ.心理功能机制的实验研究

以２４个人格形容词为材料,对１１１名大学生被试进行了“过去的我”、“现在的我”和“将来的我”三择一式的迫选反应实验,再配合时间标定作业。结果不仅验证了前文的研究结论,即不同同一性状态的被试在时间透视的广度、方向及关联性等心理结构特征上存在差异,而已表明了整合自我信息的不同的功能机制。不过,这种差异主要体现在积极词上,在消极词上差异不显著。     

认知负荷取向下基于记忆-反应冲突的欺骗检测

欺骗检测一直是心理学的重要研究问题。基于欺骗理论的认知视角, 研究者提出欺骗检测的认知负荷取向。采用隐瞒信息测试这一测谎范式, 通过操纵认知负荷影响个体在虚假反应时的记忆-反应冲突解决过程, 考察增加认知负荷对欺骗检测的影响, 以期更好地揭示欺骗检测的认知机制。在此基础上, 以普通人群和犯罪嫌疑人为被试探查基于记忆-反应冲突的欺骗检测的行为和生理指标, 并根据获得的行为和生理指标, 采用机器学习方法进行建模, 预测个体的欺骗行为。研究结果将服务于司法、安防和人际交往等领域的欺骗检测。