边缘刺激条件下错误记忆的实验研究

随着研究的深入,研究者越来越关注错误记忆中的无意识成分。本研究试图采用边缘刺激这一方法研究错误记忆中的意识-无意识机制。结果发现,边缘刺激会引发错误记忆,但它不受刺激知觉时的意识-无意识水平限制;而且这种错误记忆-经发生便很稳定,不随测量时间间隔的延长而改变。另外。研究还发现材料这一因素往往会和其他因素交融在一起共同作用于错误记忆。     

错误记忆研究范式评介

文章概括评介了当前错误记忆研究的几种主要范式及其各自可能的认知机制。联想研究范式(包括集中联想研究范式与类别联想研究范式)和无意识知觉范式描述了人们对单词的错误记忆,而误导信息干扰范式和KK研究范式则描述了人们对持续事件的错误记忆。这两类不同的研究范式证实了可能存在不同类型的错误记忆,且可能具有不同的认知加工机制。它们都从一定层面上揭示了错误记忆现象的本质和特征,并为人们进行更深入的研究提供了有效的方法。     

错误记忆影响因素的实验研究

本研究采用DRM范式,考察了关联性、学习程度和时间间隔对错误记忆的影响,结果表明:(1)低学习程度和中学习程度下的再认错误率显著高于高学习程度下的再认错误率,说明错误记忆随着学习程度的增加而降低;(2)低关联程度下的再认错误率显著低于中关联程度和高关联程度下的再认错误率,说明关联性高低是引发错误记忆的重要变量;(3)时间间隔对错误再认率没有影响,说明错误记忆不具有时间上的衰退效应,一旦产生后极其顽固,不容易消退,可能更多地受无意识加工的影响。实验结果揭示了错误记忆与真实记忆之间存在着较为复杂的关系。真实记忆可能是错误记忆的根源,而二者的关系在不同影响因素条件下则既有共变又有分离。     

错误记忆的产生是否依赖对词表的有意加工：无意识激活的证据

使用DRM范式考察了错误记忆产生过程中无意识激活的存在与否。通过操纵实验任务和呈现方式,导致被试对学习词表的无意加工和不同水平的有意加工。结果发现,无意加工时所产生的对关键诱饵的无意识激活足以导致错误记忆效应,说明对词表的有意加工并非错误记忆产生所必需。随着对词表有意加工水平的提高,多次无意识激活的累积可导致增强的错误记忆效应,且表现出与真实记忆的共变,而阻断连续激活累积的因素可有效降低错误记忆     

DRM范式下心境一致性错误记忆的认知机制

本研究以自编情绪DRM词表为实验材料, 用音乐诱发正常大学生被试正性、负性和中性心境, 探讨在被试处于某种心境下时是否产生心境一致性错误记忆现象、预警能否减少心境一致性错误记忆的发生。结果表明, 正性关键诱饵在正性心境下的错误再认率显著高于中性和负性心境, 负性关键诱饵在负性心境下的错误再认率显著高于中性和正性心境, 说明正常被试也会产生心境一致性错误记忆; 预警和无预警条件下被试对关键诱饵和心境一致性关键诱饵的错误再认率无显著差异, 说明外显的预警提示并不能消除部分由无意识产生的错误记忆和心境一致性错误记忆。研究结果支持记忆的扩散激活理论和情感的联想网络理论。     

无意识信息引发的认知控制及其神经机制

对无意识信息引发的认知控制的研究是揭示意识的功能与局限的重要方法和步骤.在无意识认知控制研究中主要采用模式掩蔽和偏对比掩蔽创设无意识条件,使用客观测量方法对意识状态进行测量.作者从无意识抑制控制、无意识冲突控制和无意识错误加工三个方面回顾了近年对无意识认知控制及其神经机制的研究.已有研究从行为和认知神经研究两个方面强有力地证明了无意识认知控制的存在,揭示了其神经机制.这些研究拓展了人们对意识信息广度和深度的认识,也为未来进一步揭示意识的起源等问题奠定了一定的基础.未来的研究可以从无意识认知控制和有意识认知控制的相互转化等方面进行进一步研究.     

联系可觉察度对错误记忆的影响

本研究采用DRM词表学习法和图片刺激对学习法两种研究范式考察了关键诱饵与学习项目间联系可觉察度对错误记忆的影响。结果显示,学习项目与关键诱饵的联系可觉察度对错误记忆起重要作用:在词表学习范式中,随着联系可觉察度的提高,被试觉察到的词表的关联性更高,错误记忆就更容易发生;在刺激对学习范式中,随着联系可觉察度的提高,学习项目和关键诱饵间的差异区分性提高,导致二者间的关联性降低,从而减少错误记忆。本研究为进一步揭示错误记忆的机制、更好地理解记忆及其机制提供了新的证据,并对如何提高记忆效率具有一定的实际应用价值。     

误导信息干扰引发的错误记忆研究

本研究借鉴GSS的测验程序,以学习材料视觉呈现、团体实验的形式,在人工条件下模拟了目击者记忆过程．通过操纵材料呈现时间（20秒、40秒）与测验次数（初测、重测）两个变量,考察了该情境下错误记忆的内在机制及其动态变化特点。并进一步研究该情境下受暗示性与社会期望、自尊、心理控制源以及视觉想象生动性的关系。实验发现,40秒比20秒条件下,真实记忆效果更好,错误记忆效果更少;重测比初测时错误记忆更多。可见,真实记忆量的差异是影响错误记忆的主要因素：错误记忆较为顽固,产生后呈增加趋势。相关分析还发现,受暗示性的各种指标（yiddl、yidd2、yidd3和shift）与社会期望、自尊、心理控制源、视觉想象生动性等因素均无显著相关．与桔试的自由回忆成绩成显著负相关。     

加工分离说的发展述评

0引言九十年代初之前,关于意识与无意识记忆加工的分离研究大多基于这样一个前提：一些记忆任务反映了意识加工而另外一些记忆任务反映了无意识加工。比如,外显记忆任务如回忆与再认被认为反映了有意识的控制加工,而内障记忆任务如词干补笔测验,反映了记忆的无意识影响。尽管记忆研究者们经常认识到这个前提过于简单,但是由这一前提而发展的任务分离说,在整个八十年代由于其能较好地反映出内隐记忆加工特点,从而引发了众多研究者的兴趣。然而,随着研究的逐步深入,大量经验事实表明意识加工可能影响内隐记忆任务,同样无意识加工可…     

想象膨胀范式下错误记忆的老化效应

通过2个实验探究想象膨胀范式下老年人的错误记忆特点及其认知机制。实验1采用经典想象膨胀实验范式, 考察老年人是否会产生比年轻人更大的想象膨胀错误记忆效应; 实验2引入情景特异性诱导技术, 进一步考察老年人的想象膨胀错误记忆可能的认知机制。研究结果表明：(1)老年人与年轻人均表现出显著的想象膨胀错误记忆, 但老年人并没有比年轻人产生更多的错误记忆; (2)当通过情景特异性诱导技术有效增加了老年人在事件想象过程中的内在细节数量后, 老年人的错误记忆显著上升。该结果揭示对事件情景的想象过程是想象膨胀错误记忆发生的关键环节, 老年人没有表现出明显的老化效应, 主要是由于该群体随年龄增长表现出在回忆/想象情景事件时内部细节缺乏这一特征所致。研究结果支持了建构性情景模拟假说和激活/监测理论。     

Comparing recollective experience in true and false autobiographical memories

This study investigated whether true autobiographical memories are qualitatively distinct from false autobiographical memories using a variation of the interview method originally reported by E. F. Loftus and J. Pickrell (1995). Participants recalled events provided by parents on 3 separate occasions and were asked to imagine true and false unremembered events. True memories were rated by both participants and observers as more rich in recollective experience and were rated by participants as more important, more emotionally intense, as having clearer imagery, and as less typical than false memories. Rehearsal frequency was used as a covariate, eliminating these effects. Imagery in true memories was most often viewed from the field perspective, whereas imagery in false memories was most often viewed from the observer perspective. More information was communicated in true memories, and true memories contained more information concerning the consequences of described events. Results suggest repeated remembering can make false memories more rich in recollective experience and more like true memories. Differences between true and false memories suggest some potentially distinct characteristics of false memories and provide insight into the process of false memory creation.     

False memories for aggressive acts

Can people develop false memories for committing aggressive acts? How does this process compare to developing false memories for victimhood? In the current research we used a simple false feedback procedure to implant false memories for committing aggressive acts (causing a black eye or spreading malicious gossip) or for victimhood (receiving a black eye). We then compared these false memories to other subjects' true memories for equivalent events. False aggressive memories were all too easy to implant, particularly in the minds of individuals with a proclivity towards aggression. Once implanted, the false memories were indistinguishable from true memories for the same events, on several dimensions, including emotional content. Implications for aggression-related memory more generally as well as false confessions are discussed.     

Distinguishing between memory illusions and actual memories using phenomenological measurements and explicit warnings

Previous research has demonstrated that the false memory effect is robust and that false memories are essentially indistinguishable from memories for events that actually occurred. The current study used several techniques intended to eliminate false memories (source monitoring decisions, confidence ratings, remember/know judgments, and explicit warnings). A robust false memory effect was found in each experiment. However, participants were able to differentiate false memories and actual memories when using specific phenomenological tasks. The current findings provide insight into basic human memory processes.     

Memory illusions and consciousness: Examining the phenomenology of true and false memories

Several recent false memory studies have addressed the question of how false memories are experienced phenomenologically. In this article we argue that it is not only possible to address questions of this sort, but it is necessary for a full understanding of memory illusions. We define memory illusions as false beliefs about the past that are experienced as memories. We then review a corpus of evidence that addresses the phenomenological experience of false memories. None of this evidence is perfect, but taken in its totality it suggests that false memories are similar to true memories but are also subtly different. We conclude with several recommendations for how the phenomenology of false memories can be fruitfully explored.     

Neural correlates underlying true and false associative memories

Despite the fact that associative memory studies produce a large number of false memories, neuroimaging analyses utilizing this paradigm typically focus only on neural activity mediating successful retrieval. The current study sought to expand on this prior research by examining the neural basis of both true and false associative memories. Though associative false memories are substantially different than those found in semantic or perceptual false memory paradigms, results suggest that associative false memories are mediated by similar neural mechanisms. Specifically, we found increased frontal activity that likely represents enhanced monitoring and evaluation compared to that needed for true memories and correct rejections. Results also indicated that true, and not false associative memories, are mediated by neural activity in the MTL, specifically the hippocampus. Finally, while activity in early visual cortex distinguished true from false memories, a lack of neural differences between hits and correct rejections failed to support previous findings suggesting that activity in early visual cortex represents sensory reactivation of encoding-related processing.     

Neural processing associated with true and false memory retrieval

We investigated the neural bases for false memory with fMRI by examining neural activity during retrieval processes that yielded true or false memories. We used a reality monitoring paradigm in which participants saw or imagined pictures of concrete objects. (A subsequent misinformation task was also used to increase false memory rates.) At test, fMRI data were collected as the participants determined whether they had seen or had only imagined the object at study. True memories were of seen pictures accurately endorsed as seen, and for false memories were of imagined pictures falsely endorsed as seen. Three distinct patterns of activity were observed: Left frontal and parietal activity was not different for true and for false memories, whereas activity was greater for true than for false memories in occipital visual regions and posterior portions of the parahippocampal gyrus, and activity was greater for false than for true memories in right anterior cingulate gyrus. Possible interpretations are discussed.     

Assessing the effectiveness of warnings and the phenomenological characteristics of false memories

The phenomenology of false memories was investigated in three experiments in which participants heard two experimenters read lists of items that were related to critical nonpresented items. In Experiments 1, following a recognition memory test, participants rated the phenomenological characteristics of their memories immediately and after a 48-hour delay. False recognition was prevalent and on several dimensions participants rated their true memories as more vivid than their false memories. In Experiments 2 and 3, following the study phase, participants were warned about the phenomenological differences between true and false memories and were instructed to use this information to avoid reporting nonpresented items. This type of warning was ineffective at reducing false recall (Experiment 2) and false recognition (Experiment 3) relative to unwarned participants. Importantly, the inability of explicit warnings to impact illusory recollections demonstrates that the false memories cannot be attributed simply to a criterion shift.     

Assessing the effectiveness of warnings and the phenomenological characteristics of false memories

The phenomenology of false memories was investigated in three experiments in which participants heard two experimenters read lists of items that were related to critical nonpresented items. In Experiments 1, following a recognition memory test, participants rated the phenomenological characteristics of their memories immediately and after a 48-hour delay. False recognition was prevalent and on several dimensions participants rated their true memories as more vivid than their false memories. In Experiments 2 and 3, following the study phase, participants were warned about the phenomenological differences between true and false memories and were instructed to use this information to avoid reporting nonpresented items. This type of warning was ineffective at reducing false recall (Experiment 2) and false recognition (Experiment 3) relative to unwarned participants. Importantly, the inability of explicit warnings to impact illusory recollections demonstrates that the false memories cannot be attributed simply to a criterion shift.     

Affect influences false memories at encoding: evidence from recognition data

Memory is susceptible to illusions in the form of false memories. Prior research found, however, that sad moods reduce false memories. The current experiment had two goals: (1) to determine whether affect influences retrieval processes, and (2) to determine whether affect influences the strength and the persistence of false memories. Happy or sad moods were induced either before or after learning word lists designed to produce false memories. Control groups did not experience a mood induction. We found that sad moods reduced false memories only when induced before learning. Signal detection analyses confirmed that sad moods induced prior to learning reduced activation of nonpresented critical lures suggesting that they came to mind less often. Affective states, however, did not influence retrieval effects. We conclude that negative affective states promote item-specific processing, which reduces false memories in a similar way as using an explicitly guided cognitive control strategy.     

Can false memories spontaneously recover?

Can false memories that were suppressed at one time spontaneously recover at a later time? Fuzzy trace theory and activation-monitoring theory predict that false memories in the Deese, Roediger, and McDermott (DRM) procedure become substantially reduced as list learning progresses because participants employ a memory-editing process. It follows that if the editing process is rendered less effective, false memories should spontaneously recover. We found that after DRM lists were well learned and false recognition to critical words was substantially reduced by multiple study-test trials, those false memories spontaneously recovered when participants were either rushed or delayed on a retest. We attributed the reduction in false recognition over trials to a memory-editing process that suppresses false recognition as participants gradually learn which words were in the lists and which words, though similar, were not. Rushing or delaying the participants on a retest made it more difficult for them to edit their memory, and false memories spontaneously returned.