Basolateral amygdala inactivation impairs learned (but not innate) fear response in rats

Numerous studies have suggested that the amygdala is involved in the formation of aversive memories, but the possibility that this structure is merely related to any kind of fear sensation or response could not be ruled out in previous studies. The present study investigated the effects of bilateral inactivation of the amygdaloid complex in rats tested in the plus-maze discriminative avoidance task. This task concomitantly evaluates aversive memory (by discrimination of the two enclosed arms) and innate fear (by open-arm exploration). Wistar rats (3-5 months-old) were implanted with bilateral guide cannulae into basolateral amygdala. After surgery, all subjects were given 1 week to recover before behavioral experiments. Afterwards, in experiment 1, 15 min prior to training, 0.5 μl of saline or muscimol (1 mg/ml) was infused in each side via microinjection needles. In experiment 2 the animals received injections immediately after the training session and in experiment 3 rats were injected prior to testing session (24 h after training). The main results showed that (1) pre-training muscimol prevented memory retention (evaluated by aversive arm exploration in the test session), but did not alter innate fear (evaluated by percent time in open arms); (2) post-training muscimol impaired consolidation, inducing increased percent in aversive arm exploration in the test session and (3) pre-testing muscimol did not affect retrieval (evaluated by aversive enclosed arm exploration in the test session). The results suggest that amygdala inactivation specifically modulated the learning of the aversive task, excluding a possible secondary effect of amygdala inactivation on general fear responses. Additionally, our data corroborate the hypothesis that basolateral amygdala is not the specific site of storage of aversive memories, since retention of the previously learned task was not affected by pre-testing inactivation.     

评价恐惧理论及相关研究述评

社交焦虑认知行为模型将负面评价恐惧作为社交焦虑的核心特征, Weeks和Heimberg提出评价恐惧概念并认为, 无论是正面评价恐惧还是负面评价恐惧, 都是社交焦虑的核心特征。Watson和Friend提出负面评价恐惧至今已有40年, 负面评价恐惧的测量工具、遗传特质、注意偏向及其在学习等领域中的应用已有相关研究。而正面评价恐惧的研究才刚刚开展。评价恐惧测量工具的完善、研究内容的拓展、临床干预的充实、跨文化研究的加强等都是未来的研究方向。     

研究生对导师负面评价的恐惧与师徒文化内隐观的关系

本研究旨在探索“怕导师”现象的文化原因,从师徒关系内隐观分析“怕导师”的影响因素。采用问卷调查和启动实验的研究方法,结果表明：（1）“怕导师”现象是存在的,即研究生害怕来自导师的负面评价。相比女性导师,研究生更害怕男性导师;导师的职称会影响研究生的害怕程度,当导师是教授时,研究生更为害怕。（2）研究生的师徒关系内隐观与其负面评价恐惧有关,越具有“学从师教”观念的人越害怕来自导师的负面评价。（3）“学从师教”文化观的启动会影响研究生对导师负面评价的恐惧程度。     

长期双酚A暴露对成年小鼠恐惧记忆的影响

双酚A (bisphenol, BPA)是一种广泛应用于塑料制品的环境内分泌干扰物, 具有弱雌激素和抗雄激素活性, 与雌激素受体有一定的亲和力。本实验探讨长期BPA暴露对成年小鼠恐惧记忆的影响及其神经机制。将9周龄雄性小鼠暴露于BPA (0.4、4、40 mg/kg/d) 90 d, 建立小鼠亚慢性BPA暴露模型后, 进行场景性条件恐惧训练, 然后分别在电击后1 hr及24 hr检测小鼠的僵立时间, 同时在电击前、电击后1 hr及24 hr检测海马相关蛋白表达变化。结果表明, BPA (4、40 mg/kg/d)暴露延长小鼠场景性条件恐惧训练后1 hr及24 hr的僵立时间。Western blot蛋白检测结果显示, 行为训练前, BPA降低了小鼠NMDA受体NR1亚基表达水平, 上调组蛋白去乙酰化酶2表达。行为训练后1 hr及24 hr, BPA促进海马NMDA受体亚基NR1和组蛋白H3乙酰化表达, 抑制组蛋白去乙酰化酶2表达, 同时促进ERK1/2磷酸化水平。以上结果表明, 长期BPA暴露提高成年小鼠恐惧记忆获得的同时延长恐惧记忆的保持; 该作用可能通过激活海马的ERK1/2通路而改变核内组蛋白乙酰化和NMDA受体水平进行。     

基于知觉的恐惧泛化的认知神经机制

恐惧泛化是条件性恐惧反应转移到另一个相似但安全的刺激的现象。适当的恐惧泛化对人类有积极意义, 而过度的恐惧泛化则不利于个体有效地适应环境。基于知觉的恐惧泛化研究揭示了恐惧泛化的规律, 因而被广泛应用。本文首先梳理了对知觉恐惧泛化的相关研究, 介绍恐惧泛化的经典理论基础—巴普洛夫条件反射以及恐惧泛化梯度; 其次简要回顾基于多个感觉通道(即视觉、听觉、情景)的知觉恐惧泛化研究现状; 再次, 分别对海马、杏仁核、脑岛和前额叶等脑区在恐惧泛化中的作用进行回顾, 进一步总结出恐惧泛化的神经环路结构模型。最后, 简要区分了基于知觉的恐惧泛化和正在兴起的基于概念的恐惧泛化, 进而指出未来研究需要结合基于概念的恐惧泛化、区分被试对刺激的辨别力、增加恐惧刺激材料的准确性及多样化、结合激素等个体差异和多模态脑成像数据来展开。     

厌恶与恐惧情绪习得的性别差异研究:一项ERP研究

采用事件相关电位技术（ERPs）,用条件性习得范式探讨厌恶与恐惧情绪习得的性别差异。行为结果表明,在成功习得厌恶、恐惧和中性情绪之后,男女性在唤醒度维度上,性别差异显著;脑电结果表明,在早期N1和P2成分,厌恶情绪与恐惧情绪的习得无显著性别差异;但男女不同性别在N2成分上差异显著,主要表现为女性在厌恶、恐惧、中性这三类CS的N2成分均差异显著,但男性仅厌恶与中性情绪的CS差异显著。结果表明在负性情绪的习得中,女性比男性更敏感。     

Fear Appeals Revisited: Testing a Unique Anti-smoking Film

Past research has found that fear-arousing persuasive messages can significantly affect attitudes, intentions, and behaviors. In this study, participants in high and low threat conditions viewed appropriately edited versions of a unique fear appeal video used in the American Lung Association’s anti-smoking campaign, while control condition participants viewed no film. Threat condition participants expressed stronger anti-smoking behavioral intentions than did control condition participants. These results represent the first effectiveness test of this widely used film.     

Living up to high standards and psychological distress

We argue and demonstrate that setting high standards, an essential aspect of perfectionism, is not associated with maladaptive responses in and of itself. Rather, our findings suggest that people's responses to their perceptions that they consistently fail to meet their own standards are maladaptive. More importantly, in the present survey study (n = 293), we extend previous research by showing that low personal standards and the perception that others are imposing high standards on the self operate in concert to strengthen the link between perceived discrepancy and psychological distress. Furthermore, in support of our moderation‐mediation model, regression analyses provided evidence for the mediating role of generalised self‐efficacy beliefs. Copyright © 2008 John Wiley & Sons, Ltd.     

An examination of message-relevant affect in road safety messages: Should road safety advertisements aim to make us feel good or bad?

Drawing upon the multiple roles of affect posited by Elaboration Likelihood Model, the current paper examines the effectiveness of message-relevant affect. Specifically, humourous and fear-evoking anti-drink driving messages are examined in terms of perceptions of relative influence on self and others (i.e., the third-person effect) and their performance on a range of persuasion outcomes. The influence of involvement, response efficacy, and gender on persuasion outcomes is also examined. Participants (N = 201) viewed two advertisements and completed two questionnaires: the first, assessed pre-exposure attitudes and behaviour and immediate-post exposure attitudes and intentions; the second, 2–4 weeks later, assessed attitudes and behaviour. The results revealed, as predicted, interactions of the key variables and evidence of the greater persuasiveness of negative appeals immediately after exposure whilst greater improvement of positive appeals over time. The findings highlight the importance of continuing the exploration of positive appeals as a persuasive alternative to negative appeals.     

Beyond Fear Emotional Memory Mechanisms in the Human Brain

ABSTRACT— Neurobiological accounts of emotional memory have been derived largely from animal models investigating the encoding and retention of memories for events that signal threat. This literature has implicated the amygdala, a structure in the brain's temporal lobe, in the learning and consolidation of fear memories. Its role in fear conditioning has been confirmed, but the human amygdala also interacts with cortical regions to mediate other aspects of emotional memory. These include the encoding and consolidation of pleasant and unpleasant arousing events into long-term memory, the narrowing of focus on central emotional information, the retrieval of prior emotional events and contexts, and the subjective experience of recollection and emotional intensity during retrieval. Along with other mechanisms that do not involve the amygdala, these functions ensure that significant life events leave a lasting impression in memory.