Dopamine D1 receptors are responsible for stress-induced emotional memory deficit in mice

It is established that stress impairs spatial learning and memory via the hypothalamus-pituitary-adrenal axis response. Dopamine D1 receptors were also shown to be responsible for a stress-induced deficit of working memory. However, whether stress affects the subsequent emotional learning and memory is not elucidated yet. Here, we employed the well-established one-trial step-through task to study the effect of an acute psychological stress (induced by tail hanging for 5, 10, or 20?min) on emotional learning and memory, and the possible mechanisms as well. We demonstrated that tail hanging induced an obvious stress response. Either an acute tail-hanging stress or a single dose of intraperitoneally injected dopamine D1 receptor antagonist (SCH23390) significantly decreased the step-through latency in the one-trial step-through task. However, SCH23390 prevented the acute tail-hanging stress-induced decrease in the step-through latency. In addition, the effects of tail-hanging stress and/or SCH23390 on the changes in step-through latency were not through non-memory factors such as nociceptive perception and motor function. Our data indicate that the hyperactivation of dopamine D1 receptors mediated the stress-induced deficit of emotional learning and memory. This study may have clinical significance given that psychological stress is considered to play a role in susceptibility to some mental diseases such as depression and post-traumatic stress disorder.     

Distinct processing for pictures of animals and objects: evidence from eye movements

Many studies have suggested that emotional stimuli orient and engage attention. There is also evidence that animate stimuli, such as those from humans and animals, cause attentional bias. However, categorical and emotional factors are usually mixed, and it is unclear to what extent human context influences attentional allocation. To address this issue, we tracked participants' eye movements while they viewed pictures with animals and inanimate images (i.e., category) as focal objects. These pictures had either negative or neutral emotional valence, and either human body parts or nonhuman parts were near the focal objects (i.e., context). The picture's valence, arousal, position, size, and most of the low-level visual features were matched across categories. The results showed that nonhuman animals were more likely to be attended to and to be attended to for longer times than inanimate objects. The same pattern held for the human contexts (vs. nonhuman contexts). The effects of emotional valence, category, and context interacted. Specifically, in images with a negative valence, focal animals and objects with human context had comparable numbers of gaze fixations and gaze duration. These results highlighted the attentional bias to animate parts of a picture and clarified that the effects of category, valence, and picture context interacted to influence attentional allocation.     

Exposure to severe urban air pollution influences cognitive outcomes, brain volume and systemic inflammation in clinically healthy children

Exposure to severe air pollution produces neuroinflammation and structural brain alterations in children. We tested whether patterns of brain growth, cognitive deficits and white matter hyperintensities (WMH) are associated with exposures to severe air pollution. Baseline and 1 year follow-up measurements of global and regional brain MRI volumes, cognitive abilities (Wechsler Intelligence Scale for Children-Revised, WISC-R), and serum inflammatory mediators were collected in 20 Mexico City (MC) children (10 with white matter hyperintensities, WMH⁺, and 10 without, WMH⁻) and 10 matched controls (CTL) from a low polluted city. There were significant differences in white matter volumes between CTL and MC children - both WMH⁺ and WMH⁻ - in right parietal and bilateral temporal areas. Both WMH⁻ and WMH⁺ MC children showed progressive deficits, compared to CTL children, on the WISC-R Vocabulary and Digit Span subtests. The cognitive deficits in highly exposed children match the localization of the volumetric differences detected over the 1 year follow-up, since the deficits observed are consistent with impairment of parietal and temporal lobe functions. Regardless of the presence of prefrontal WMH, Mexico City children performed more poorly across a variety of cognitive tests, compared to CTL children, thus WMH⁺ is likely only partially identifying underlying white matter pathology. Together these findings reveal that exposure to air pollution may perturb the trajectory of cerebral development and result in cognitive deficits during childhood.     

分段是视频学习的有效方式吗?

教育心理学中的分段原则认为,将视频学习材料分割成几个小片段进行学习的效果更好。以往关于分段的研究通过两个角度的操纵考察了分段在学习中的作用,一方面是交互性角度,学习者自己控制的分段及系统分段;另一方面是结构性角度,分段是在任意时间点划分和有意义时间点上划分。通过对以往研究结果的整理发现,大部分研究证明分段学习相较于连续学习的成绩更好,并且能降低学习者在学习过程中的感知难度, 提高积极的情感状态,但是对心理努力的影响比较微弱。研究者们从事件分割理论和认知负荷理论的视角对分段的效果做出了解释。未来研究需要继续关注分段的边界条件、拓宽研究的范围、探究分段的认知神经基础等不断完善分段原则在教学中的应用。     

负性情绪在冲突适应中的作用机制：分离与整合视角

负性情绪如何影响冲突适应一直以来受到领域内研究者们的广泛关注。根据负性情绪产生的源头(冲突外部操纵vs.冲突内部固有), 对于该问题的论述可以分别从认知与情绪的分离与整合视角展开。分离视角下, 操纵于冲突之外的负性情绪(外部负性情绪)独立于冲突加工过程, 通过情绪加工系统或个体自身的动机/唤醒水平影响冲突适应。近些年来的研究发现冲突加工自动产生负性情绪(固有负性情绪), 寓示着认知冲突与负性情绪间的内在关联, 固有负性情绪因此可被视作诱发冲突适应的另一个有效来源。整合视角下, 操纵于冲突内部的(固有)负性情绪高度整合于冲突加工过程, 其功能与冲突信息类似, 通过内在地促进目标导向行为直接诱发冲突适应。对这一主题的论述加深了我们对负性情绪如何作用于冲突适应过程的理解, 也为探索认知与情绪系统的整合过程及作用机制提供了一个全新的视角, 在此基础上, 我们也提出一些未来可行的研究方向。     

居危思变?工作不安全感对创新行为的差异化影响?

企业往往在员工管理和组织创新上处于“两难困境”——难以提供稳定工作但又不得不依赖员工实现组织创新, 这就使得研究员工工作不安全感对创新行为的影响至关重要。企业员工遭遇不同环境威胁带来的工作不安全感时, 创新行为存在差异。本文在威胁焦点下深化工作不安全感概念, 并基于“以变量为中心”和“以人为中心”的研究思路, 探讨其对创新行为的差异化影响过程。首先, 结合环境威胁来源与主观感知, 把工作不安全感分为岗位焦点工作不安全感和人员焦点工作不安全感两个维度, 并将编制测量量表。其次, 期望运用纵向研究设计, 通过分析多时点的员工-主管配对数据, 基于情境调节焦点和工作激情的链式中介作用, 来揭示岗位焦点工作不安全感对创新行为的负向影响, 以及人员焦点工作不安全感对创新行为的倒U型影响。最后, 将采取“以人为中心”的研究思路, 运用潜在剖面分析方法探讨工作不安全感潜在类型及其对创新行为的影响。研究结果将有助于推进工作不安全感的概念和效用研究, 也为企业如何有效促进创新提供对策建议。     

老年人群的韵律感知

老龄化导致听觉系统、认知功能有所衰退。老年人群的言语理解能力减弱, 韵律信息解析存在困难。老年人对重音、语调、语速等语言韵律感知能力退化, 对情感韵律的加工也出现问题, 特别是消极情绪韵律加工减退较快。老年疾病进一步加深韵律加工难度, 韵律感知呈现出与特定疾病的相关性。未来研究需考察不同语言背景老年人群的韵律感知表现与机制、复杂交流环境的影响、韵律感知障碍对老年疾病的预测、韵律感知的早期干预与复健等问题。     

The Impact of Perceived Discrimination on Mental Health Among Chinese Migrant and Left-Behind Children: A Meta-analysis

In China, rural–urban migration is one of major influences on the mental health of migrant and left-behind children. Literature suggests that the perception of discrimination is an important factor that influences the mental health of these children. The present research explores (1) whether migrant children and left-behind children are different in the relationship between the perception of discrimination and mental health, and (2) whether the relationship between the perception of discrimination and mental health of these children is moderated by gender and age. Using a meta-analytic technique, the authors included 26 studies (generating 48 independent samples) with a total sample size of 28,883 participants. Results showed that the perception of discrimination of migrant children was negatively correlated with positive indicators of mental health, and it has a stronger effect than left-behind children; the perception of discrimination of migrant children was positively correlated with negative indicators of mental health, and it has a weaker effect than left-behind children. Additionally, gender moderated the relationship between the perception of discrimination and the positive indicators of mental health among left-behind children, while age moderated such relationship among migrant children.

     

难治性丙型肝炎研究新进展

随着聚乙二醇化干扰素(IFN)的普及应用和慢性丙型肝炎规范化治疗的开展,其治愈率不断提高.但疗效不佳的慢性丙型肝炎患者不断积累,难治性慢性丙型肝炎患者成为临床医生必须面对的挑战.难治性丙型肝炎患者应当分为两类,第一类为“难治疗”性慢性丙型肝炎患者,该类患者由于宿主条件限制,不能耐受IFN联合利巴韦林(RBV)的标准治疗,如儿童和老年人、慢性肾功能衰竭患者等.第二类为“难治愈”性慢性丙型肝炎患者,该类患者可以耐受标准治疗方案,但按照应答指导的治疗原则(RGT)治疗后,效果仍然不佳或复发.本文就近年关于难治性丙型肝炎的研究进展,从难治性丙型肝炎的定义、机制、治疗诸方面作一综述.     

根据血压昼夜节律选择服药时间控制血压晨峰

根据血压昼夜节律,观察给药时间对血压晨峰的影响。256例原发性高血压患者,经24h动态血压监测分为超杓型（n＝49）、杓型（n＝127）和非杓型（n＝80）3组;各组再分为清晨服药组和晚上服药组。用药6周,比较用药前后血压昼夜节律及血压晨峰的变化,发现在改变血压昼夜节律及降低血压晨峰方面,超杓型组清晨服药优于晚上服药,非杓型组晚上服药优于清晨服药;杓型组清晨服药与晚上服药均能降低晨峰值,提示根据个体血压昼夜节律选择服药时间能更好地控制血压晨峰。