记忆活动中情绪调节的效果和认知神经机制

情绪对记忆的促进作用, 已得到了大量研究的证实。但是, 情绪对记忆的损害作用还没有得到一致的研究结果。情绪诱导的记忆损害的条件和机制还没有得到很好的确认和解释。并且, 在证实了情绪对记忆的影响之后, 一个更具有现实意义的问题是, 人类能够在多大程度上调控情绪对记忆的影响呢？虽然已有的情绪调节研究对一些重要的情绪调节策略如认知重评和抑制进行了较多的探讨, 考察了情绪调节对情绪事件记忆的影响。但是, 关于情绪调节是否可以有效地调整情绪唤醒对中性项目记忆的影响, 目前只有少量的研究。对情绪调节影响记忆的认知神经机制还所知甚少。因此, 本项目拟综合使用行为测量和认知神经科学技术, 在考察情绪唤醒对记忆的损害效应的条件和机制的基础上, 进一步探讨认知重评、抑制和忽视等情绪调节策略调控记忆中的情绪效应的有效性和认知神经机制。研究结果将会有助于对情绪、情绪调节和记忆的关系的理解, 并对促进学生的学习记忆活动有现实意义。     

有意遗忘的脑机制

有意遗忘是指个体主动忘记无用和过时的信息,本质是记忆的主动抑制,包括定向遗忘和压抑遗忘。在定向遗忘中,记忆抑制既发生在编码阶段也发生在提取阶段,脑机制研究支持编码抑制理论和提取抑制理论;在压抑遗忘中,think和No-think所激活的脑区不同,No-think引起前额区域的激活增强和海马的激活减弱。未来应开展定向遗忘和压抑遗忘的脑机制差异研究,注重记忆抑制和其他心理活动抑制之间的差异研究,关注创伤个体的有意遗忘研究,拓展记忆控制神经网络的可塑性研究。     

催产素影响条件化恐惧情绪加工的认知机制及神经基础

恐惧是一种与进化密切相关的情绪,对人类的生存与适应具有重要价值。过度的恐惧可能会导致恐惧症、焦虑症和创伤后应激障碍等病理性恐惧的产生。而催产素对各种病理性恐惧的干预和治疗具有重要的价值。因此,研究拟采用行为和fMRI技术,系统探究催产素影响条件化恐惧情绪加工的认知神经机制。重点关注:(1)催产素影响恐惧习得的认知神经机制;(2)催产素影响恐惧记忆巩固的认知神经机制;(3)催产素影响恐惧记忆再巩固的认知神经机制;(4)催产素影响恐惧消退的认知神经机制。这项研究的开展对于探究催产素影响条件化恐惧情绪加工的认知神经机制具有很高的科学价值,对于各种病理性恐惧的干预与治疗也具有重要的应用价值。     

提取诱发遗忘中的情绪记忆权衡效应

情绪记忆的提取诱发遗忘研究是近年来记忆研究领域的热点问题,但是尚无一致的结果。在现实生活中,我们所面临的情绪事件十分复杂,不仅包含核心的情绪信息,还包括边缘非情绪信息,研究已发现,人们对于这些复杂情绪事件不同成分的记忆效果也不是完全相同的。本研究通过2个实验分别探讨提取练习整张复杂情绪图片和提取练习复杂情绪图片的背景成分时的提取诱发遗忘现象。结果表明:(1)无论提取练习完整信息还是相关的边缘信息,均在提取诱发遗忘中存在显著的情绪记忆权衡效应;(2)消极情绪项目像中性项目一样也能产生提取诱发遗忘效应;(3)不论提取图片的完整信息还是背景信息,都仅在中心项目上表现出提取诱发遗忘,边缘背景没有出现提取诱发遗忘。     

情绪唤醒影响记忆巩固过程的神经生理机制

白鼠和人类都对情绪唤醒的经历有更好的记忆。情绪唤醒影响记忆巩固的神经生理机制主要有以下几种方式:(a)情绪唤醒或急性应激,会引发个体内部应激激素的释放,从而增强其记忆巩固过程。(b1)杏仁核的激活对情绪唤醒影响记忆巩固过程十分重要,杏仁核内部去甲肾上腺素(NE)的释放影响记忆巩固过程。(b2)杏仁核投射到负责不同类型记忆加工的脑区,如海马和皮层,从而影响记忆。(c)应激激素影响记忆巩固的过程中,杏仁核内NE的激活在这一过程中扮演着重要角色。综上,情绪唤醒影响记忆巩固的过程,涉及到激素调节、神经调节及二者的共同作用。     

调控去甲肾上腺素能系统对防治创伤后应激障碍的影响

个体经历严重创伤性事件后可能会形成创伤后应激障碍(posttraumatic stress disorder, PTSD)。在创伤经历中形成的情绪记忆是以后发展为PTSD的重要病理机制。PTSD的形成涉及到情绪记忆的过度巩固, 而去甲肾上腺素能神经信号可增强情绪记忆的巩固和再巩固。因此, 在创伤记忆的巩固和再巩固期间阻断去甲肾上腺素能神经信号, 而在创伤记忆的消退期间增强去甲肾上腺素能神经信号, 可能会破坏和或抑制病理性的情绪记忆, 从而预防或治疗PTSD。     

试论消退抑制能否作为遗忘的神经机制问题

遗忘是与记忆有关的一个重要问题。与记忆相反,遗忘是在识记之后,表现为不能认知或再现,错误的认知或再现。要与遗忘作斗争,必须了解遗忘及其神经机制问题。本文仅就其中关于消退抑制能否作为遗忘的神经机制问题加以论述。一消退抑制,曾被用来解释遗忘发生的神经机制。苏联阿·阿·斯米尔诺夫等主编的《心理学》认为:"首先遗忘的是对人没有最重要意义的、不能引起他的兴趣的、不符合他的需要的、在他的活动中不占据主要地位的,因而没有获得充分强化的那种东西。因为在这些场合,消退抑制就很快地发展起来。"①这种看法,在我国心理学界和生理学界发生丁一定影响。从过去内部交流的一些心理学讲义来看,大多把消退抑制看作某种遗忘的神经机制。即使最近出版的心理学著作,也还有这种看法。例如,供综合性大     

情绪性记忆的定向遗忘效应

刺激的情绪性具有增强记忆的效果,那么,带有情绪信息的刺激对遗忘又会产生怎样的影响？已有研究从行为及认知神经机制层面探讨了情绪性刺激对定向遗忘效应的影响,但结果并不一致。总结已有文献发现,以情绪性刺激的材料类型、情绪效价、唤醒度和熟悉度为主的客观因素和以被试的情绪状态为主的主观因素均为影响定向遗忘效应产生及其稳定性的重要原因。这类研究是对有意遗忘研究领域的重要补充,也加深了人们对有意遗忘机制的理解。     

自豪感的神经基础：比较的视角

自豪感是对自身成就进行评估时产生的积极情绪体验。神经基础研究表明, 心理理论、自我参照、情绪、奖赏和记忆等相关脑区的协同作用构成了自豪感的神经基础, 而神经和生理的比较研究则揭示了自豪感和其他基本情绪以及道德情绪等在神经基础上的异同。以上结果为理解自豪感的复杂神经机制提供了依据。未来研究应对不同种类自豪感以及自豪感与认知过程相互作用的神经机制进行深入探讨。     

情绪汉词的主动遗忘效应:ERP研究

尽管证明人类具有主动遗忘能力的研究比较多,但是,探索情绪汉词主动遗忘效应以及电生理机制的实验却非常少。本研究采用事件相关电位技术、T/NT范式探索情绪汉词主动遗忘效应。实验一(行为研究)的结果显示,在中性和情绪汉词条件下,不回忆组的正确率都显著低于基线组,即得到了主动遗忘效应。同时,情绪汉词的主动遗忘效应量小于中性汉词。实验二(脑电研究)结果显示,在200-300ms,Fz,Cz,Pz电极点,回忆组的P2波幅高于不回忆组。在300-400ms,在Fz,Cz,Pz电极点,不回忆组的N2波幅高于回忆组。N2跟抑制过程高度相关,提示抑制是主动遗忘的一个主要原因。在400-500ms,在Pz电极点,回忆组的LPC波幅高于不回忆组。顶叶LPC跟记忆提取高度相关,提示主动遗忘阻止了回忆,这可能是主动遗忘效应发生的内在机制     

Individual differences in the suppression of unwanted memories: the executive deficit hypothesis

When confronted with reminders to an unpleasant memory, people often try to prevent the unwanted memory from coming to mind. In this article, we review behavioral and neurocognitive evidence concerning the consequences of exerting such control over memory retrieval. This work indicates that suppressing retrieval is accomplished by control mechanisms that inhibit the unwanted memories, making them harder to recall later, even when desired. This process engages executive control mechanisms mediated by the lateral prefrontal cortex to terminate recollection-related activity in the hippocampus. Together, these findings specify a neurocognitive model of how memory control operates, suggesting that executive control may be an important means of down-regulating intrusive memories over time. We conclude by proposing that individual differences in the regulation of intrusive memories in the aftermath of trauma may be mediated by pre-existing differences in executive control ability. In support of this executive deficit hypothesis, we review the recent work indicating links between executive control ability and memory suppression.     

Suppressing Unwanted Memories

ABSTRACT— When reminded of something we would prefer not to think about, we often try to exclude the unwanted memory from awareness. Recent research indicates that people control unwanted memories by stopping memory retrieval, using mechanisms similar to those used to stop reflexive motor responses. Controlling unwanted memories is implemented by the lateral prefrontal cortex, which acts to reduce activity in the hippocampus, thereby impairing retention of those memories. Individual differences in the efficacy of these systems may underlie variation in how well people control intrusive memories and adapt in the aftermath of trauma. This research supports the existence of an active forgetting process and establishes a neurocognitive model for inquiry into motivated forgetting.     

Intentional suppression of unwanted memories grows more difficult as we age

People often encounter reminders to memories that they would prefer not to think about. When this happens, they often try to exclude the unwanted memory from awareness, a process that relies upon inhibitory control. We propose that the ability to regulate awareness of unwanted memories through inhibition declines with advancing age. In two experiments, we examined younger and older adults' ability to intentionally suppress retrieval when repeatedly confronted with reminders to an experience they were instructed to not think about. Older adults exhibited significantly less forgetting of the suppressed items compared to younger adults on a later independent probe test of recall, indicating that older adults failed to inhibit the to-be-avoided memories. These findings demonstrate that the ability to intentionally regulate conscious awareness of unwanted memories through inhibitory control declines with age, highlighting differences in memory control that may be of clinical relevance in the aftermath of unpleasant life events.     

条件性恐惧记忆消退的提取干预范式及其作用的神经机制

基于记忆再巩固理论的恐惧记忆提取干预范式被证明可以有效消退恐惧记忆, 能克服传统消退容易复发的缺点。该范式通过单独呈现条件刺激激活原有恐惧记忆, 使记忆重返不稳定状态, 随后在再巩固时间窗内实施干预则能改写原有记忆。目前该范式起作用的神经机制尚不明确, 本文在现有的人类研究和动物研究基础上, 总结了杏仁核、前额叶和海马三个脑区在提取干预过程中的作用, 以及该领域研究的争议点, 为之后的研究提供思路。     

基于Think/No-think范式的动机性遗忘研究:行为与脑机制

想/不想范式(Think/No-think,TNT)是基于go/no-go范式提出来的用于研究动机性遗忘过程的实验范式,主要过程是指个体对于记忆的提取抑制可以导致随后该记忆的遗忘。近年来TNT范式的大量行为学研究都一致性地发现记忆提取抑制可以产生负性控制效应,验证了在实验室情境下对动机性遗忘进行研究的可行性。其中,负性控制效应指的是压抑条件的项目相对于基线条件的项目的回忆量有显著降低。关于动机性遗忘发生的神经机制的探讨已积累了大量的研究证据,总结脑电(EEG)和功能核磁共振(f MRI)两个模态的研究,我们提出了动机性遗忘发生的多模态功能网络模型。最后,在该模型的基础上,我们展望了TNT范式未来的研究方向,其中特别注意到同步EEG-f MRI技术的应用有望为我们揭示出记忆提取抑制导致的动机性遗忘发生的动态过程。     

自我参照对情绪性记忆定向遗忘的影响

关于自我参照效应的研究大多从信息编码角度考察自我参照的加工优势, 但作为记忆过程的另一重要方面, 自我参照对遗忘影响的研究较少。遗忘自身经历的情绪性记忆是日常生活中的常见现象。研究采用项目法定向遗忘范式(item-method directed forgetting)考察了自我参照对情绪性记忆定向遗忘的影响。实验一和实验二的结果都表明参照方式会影响定向遗忘：自我参照条件下的材料会发生定向遗忘; 而他人参照条件下的材料不会发生定向遗忘, 两种参照方式下材料间区辨性的不同是导致这一现象的原因。此外, 实验二采用回忆测试发现：自我参照对不同效价的情绪性记忆定向遗忘产生了不同影响, 而自我提升(self-enhancement)动机在其中起着重要的调节作用。     

Inhibitory processes and the control of memory retrieval

People are often confronted with reminders of things they would prefer not to think about. When this happens, they often attempt to put the unwanted memories out of awareness. Recent research shows that the capacity to suppress distracting traces is mediated by executive-control processes that are analogous to those involved in overriding prepotent motor responses, and it is these processes that cause persisting memory failures for the suppressed items. There is evidence that memory retrieval and motor tasks that are likely to demand executive control recruit overlapping neural mechanisms, suggesting that a common process mediates control in these domains. Together, these findings indicate that memory failures often arise from the mechanisms that lie at the heart of our capacity to influence the focus of thought.     

Overcoming suppression in order to remember: Contributions from anterior cingulate and ventrolateral prefrontal cortex

The ability to remember is often compromised by competition from irrelevant memories. However, acts of selective remembering can alter the competitive relationship between memories; memories that are selected against are weakened, whereas those that are retrieved are strengthened. Whereas the weakening of selectedagainst memories is typically evidenced by subsequently poorer recall of these memories, the present study tested the hypothesis that when previously selected-against memories can subsequently be successfully retrieved, such acts of successful retrieval are associated with engagement of neurobiological mechanisms that serve to detect and overcome competition. Consistent with this hypothesis, fMRI revealed that anterior cingulate cortex and right ventrolateral prefrontal cortex are differentially engaged during successful retrieval of previously selected-against memories, and that their engagement is directly related to the magnitude of weakening that is induced by prior acts of selecting against these memories.     

Episodic remembering creates access to involuntary conscious memory: Demonstrating involuntary recall on a voluntary recall task

The idea that involuntary memory retrieval might occur during voluntary memory retrieval can be traced back to Ebbinghaus (1885/1964). However, methodological challenges have stood in the way of testing this idea. Recent diary studies of naturally occurring involuntary memories have provided insights into how this idea could be tested (Berntsen, 1998; Mace, 2005b, 2006). These studies have shown that the contents of an involuntary memory sometimes trigger additional involuntary memories, a process called chaining. It was hypothesised that chaining should also occur on autobiographical memory tasks, and this was tested in the present study by asking participants in an autobiographical memory task to report the presence of involuntary memories while they were performing the task. The results showed that involuntary memories did occur when participants were recalling the past. The results also showed involuntary memories dissociating from voluntary memories on two independent measures, thereby enhancing the credibility of the results.     

Episodic remembering creates access to involuntary conscious memory: demonstrating involuntary recall on a voluntary recall task

The idea that involuntary memory retrieval might occur during voluntary memory retrieval can be traced back to Ebbinghaus (1885/1964). However, methodological challenges have stood in the way of testing this idea. Recent diary studies of naturally occurring involuntary memories have provided insights into how this idea could be tested (Berntsen, 1998; Mace, 2005b, 2006). These studies have shown that the contents of an involuntary memory sometimes trigger additional involuntary memories, a process called chaining. It was hypothesised that chaining should also occur on autobiographical memory tasks, and this was tested in the present study by asking participants in an autobiographical memory task to report the presence of involuntary memories while they were performing the task. The results showed that involuntary memories did occur when participants were recalling the past. The results also showed involuntary memories dissociating from voluntary memories on two independent measures, thereby enhancing the credibility of the results.