Misleading postevent information and memory for events: arguments and evidence against memory impairment hypotheses

Mediators and Moderators of Reinforced Self-Affirmation as a Method for Reducing the Memory Misinformation Effect

The misinformation effect occurs when an eyewitness includes information in his or her account that is incongruent with the event he or she witnessed, and stems from being exposed to incorrect external sources. This is a serious threat to the quality of witness testimony and to the correctness of decisions reached by courts. However, few methods have been developed to reduce the vulnerability of witnesses to misinformation. This article presents such a method, namely, reinforced self-affirmation (RSA), which, by increasing memory confidence of witnesses, makes them less inclined to rely on external sources of information and more on their own memory. The effectiveness of this method was confirmed in three experiments. It was also found that memory confidence, but not general self-confidence, is a mediator of the impact of RSA on misinformation effect (ME), and that contingent self-esteem and feedback acceptance, but not sense of self-efficacy or general self-esteem, are moderators of this impact. It is concluded that RSA may be a promising basis for constructing methods, which can be used by forensic psychologists in real forensic settings.

Misinformation effects in an online sample: results of an experimental study with a five day retention interval

Traditional face-to-face laboratory studies have contributed greatly to our understanding of how misinformation effects develop. However, an area of emerging concern that has been relatively under-researched is the impact of misinformation following exposure to traumatic events that are viewed online. Here we describe a novel method for investigating misinformation effects in an online context. Participants (N = 99) completed the study online. They first watched a 10-min video of a fictional school shooting. Between 5 and 10 days later, they were randomly assigned to receive misinformation or no misinformation about the video before completing a recognition test. Misinformed participants were less accurate at discriminating between misinformation and true statements than control participants. This effect was most strongly supported by ROC analyses (Cohen's d = 0.59, BF10 = 8.34). Misinformation effects can be established in an online experiment using candid violent viral-style video stimuli.

False memory in nonhuman animals

This paper examines recent evidence from behavioral and neuroscience research with nonhuman animals that suggests the intriguing possibility that they, like their human counterparts, are vulnerable to creating false memories. Once considered a uniquely human memory phenomenon, the creation of false memories in lower animals can be seen especially readily in studies involving memory for source, or contextual attributes. Furthermore, evidence of "implanted" misinformation has also been obtained. Here, we review that research and consider its relevance to our empirical understanding of false memories, as well as speculate about its potential clinical implications for trauma memory.

Inducing resistance to the misinformation effect by means of reinforced self-affirmation: The importance of positive feedback

The misinformation effect is one of the major threats for the quality of witness testimony. It involves including of information that is inconsistent with the course of an event, and which originates from sources other than the event itself, into a witness's report of the event. In the present article research is presented aiming at reducing the tendency to rely on misinformation. After viewing a video clip, participants received a post-event narrative describing the events in the film which in the misled group included some incorrect information about the clip. They were then administered reinforced self-affirmation (RSA), a technique aiming at boosting self-confidence in order to increase the tendency to rely on own memory instead of external cues. This technique consists of self-affirmation by means of writing down one's greatest achievements in life and manipulated positive feedback. Feedback about memory, perception and independence of judgements was analyzed. All types of feedback effectively reduced the misinformation effect. Mediation analyzes confirmed that RSA operates via increased self-confidence or self-independence.

Self-delivered misinformation - Merging the choice blindness and misinformation effect paradigms

Choice blindness is the failure to detect a discrepancy between a choice and its outcome. The misinformation effect occurs when the recollection of an event changes because new, misleading information about the event is received. The purpose of this study was to merge the choice blindness and misinformation effect paradigms, and thus examine whether choice blindness can be created for individuals’ recollections of a witnessed event, and whether this will affect their later recollections of the event. Thus, as a way of delivering misinformation the participants ostensibly became their own source of the misleading information. The participants watched a short film and filled out a questionnaire about events shown in the film. Some of their answers were then manipulated using reattachable stickers, which allowed alteration of their original answers. The participants gave justifications for their manipulated choices, and later their recollection of the original event was tested through another questionnaire. Choice blindness was created for a majority of the participants. A majority of the choice blind participants later changed their reported recollection of the event in line with the manipulations, whereas only a small minority of the participants in the control condition changed their recollection. This study provides new information about the misinformation effect, suggesting that this effect also can occur when misinformation is given immediately following presentation of the original stimuli, and about choice blindness and its effects on the recollections of events. The results suggest that memory blindness can be created when people inadvertently supply themselves with misleading information about an event, causing a change in their recollection.

Reducing the Misinformation Effect Through Initial Testing: Take Two Tests and Recall Me in the Morning?

Initial retrieval of an event can reduce people's susceptibility to misinformation. We explored whether protective effects of initial testing could be obtained on final free recall and source-monitoring tests. After studying six household scenes (e.g., a bathroom), participants attempted to recall items from the scenes zero, one, or two times. Immediately or after a 48-hour delay, non-presented items (e.g., soap and toothbrush) were exposed zero, one, or four times through a social contagion manipulation in which participants reviewed sets of recall tests ostensibly provided by other participants. A protective effect of testing emerged on a final free recall test following the delay and on a final source-memory test regardless of delay. Taking two initial tests did not increase these protective effects. Determining whether initial testing will have protective (versus harmful) effects on memory has important practical implications for interviewing eyewitnesses.

Recognition performance level and the magnitude of the misinformation effect in eyewitness memory

The issue of whether misleading postevent information affects performance on the modified recognition test introduced by McCloskey and Zaragoza (1985) was examined in a meta-analysis. Results indicated that a misinformation effect can be obtained with the modified test. The meta-analysis also revealed that recognition hit rates are higher in studies that yield a misinformation effect than in studies in which the misinformation effect is not significant. The data from the meta-analysis were also used to assess whether the misinformation effect is related to the length of the retention interval. Results showed that a misinformation effect is more likely to be obtained with long retention intervals, although in the available data there is a confound between the length of the retention interval and the recognition level obtained.

The neuroscience of memory: implications for the courtroom

Although memory can be hazy at times, it is often assumed that memories of violent or otherwise stressful events are so well encoded that they are effectively indelible and that confidently retrieved memories are almost certainly accurate. However, findings from basic psychological research and neuroscience studies indicate that memory is a reconstructive process that is susceptible to distortion. In the courtroom, even minor memory distortions can have severe consequences that are partly driven by common misunderstandings about memory--for example, that memory is more veridical than it may actually be.

Individual differences in shifting decision criterion: a recognition memory study

An ability to flexibly shift a decision criterion can be advantageous. For example, a known change in the base rate of targets and distractors on a recognition memory test will lead optimal decision makers to shift their criterion accordingly. In the present study, 95 individuals participated in two recognition memory tests that included periodic changes in the base rate probability that the test stimulus had been presented during the study session. The results reveal a wide variability in the tendency to shift decision criterion in response to this probability information, with some appropriately shifting and others not shifting at all. However, participants were highly reliable in their tendency to shift criterion across tests. The goal of the present study was to explain what factors account for these individual differences. To accomplish this, over 50 variables were assessed for each individual (e.g., personality, cognitive style, state of mind). Using a regression model that incorporated different sets of factors, over 50% of the variance was accounted for. The results of the analysis describe the total, direct, and mediating effects on criterion shifting from factors that include memory strength, strategy, and inherent characteristics such as a fun-seeking personality, a negative affect, and military rank. The results are discussed with respect to understanding why participants rarely chose an optimal decision-making strategy and provide greater insight into the underlying mechanisms of recognition memory.

Susceptibility to long-term misinformation effect outside of the laboratory

OBJECTIVE

To test the effect of misinformation outside of the laboratory and to explore correlates of the effect, including arousal, cognitive ability, and neuroticism.

METHOD

About 2 months before deployment to Afghanistan, 249 soldiers enrolled in this study, which was embedded in a larger project. Two months after deployment, participants were interviewed about stressors on deployment and they received subtle misinformation about a fictional event on deployment. Seven months later, they were retested, and completed a questionnaire about events on deployment.

RESULTS

At 9 months, a total of 26% of participants reported that they had experienced the fictional event, although 7 months earlier they said they had not experienced it. Logistic regression analyses revealed that lower cognitive ability and a combination of high arousal and more stressors on deployment were related to higher susceptibility to the misinformation effect.

CONCLUSIONS

Results suggest that information provided by another source may be incorporated into related autobiographical memory, particularly for individuals with lower cognitive ability, high arousal at the time of encoding the information and more related experiences.

Priming correct information reduces the misinformation effect

The misinformation effect is a well-established phenomenon in the false memory literature, although the mechanisms that underlie it are debated. In the present study, we explored one aspect of the controversy, the fate of the original memory. We began from an activation-based view of memory, capitalizing on the well-understood processes of associative priming and spreading activation, to test the hypothesis that true and suggested information can coexist in memory. After exposure to misinformation, participants were unknowingly primed with associates of either the true or a suggested item. Misled participants who were primed for the true item performed better on a final memory test than did misled participants primed for neutral information. The results indicated that true and suggested information coexist and that retrieval is influenced by each concept's activation level at test. Implications for theories of the misinformation effect were discussed.

Overcoming the effects of intentional forgetting

The long-term effects of the compartmentalization of task-irrelevant memories were investigated using a directed forgetting procedure. Many models tacitly assume the persistence of the costs and benefits of directed forgetting or otherwise fail to predict what factors might reduce or eliminate them. In contrast, a retrieving effectively from memory model (REM; Lehman & Malmberg, 2009) predicts that intentional forgetting should only be observed for free recall when temporal context is used to probe memory. By manipulating whether study lists were constructed from category exemplars or from a random set of words, and by either providing temporal or category cues at test, we tested the prediction. The effects of directed forgetting were eliminated when categorized lists were studied and category cues were provided. When categorized lists were used but category cues were not provided, the usual costs and benefits of directed forgetting were observed. These results specify the conditions under which the consequences of intentional forgetting can be overcome.

Inoculating against eyewitness suggestibility via interpolated verbatim vs. gist testing

In real-life situations, eyewitnesses often have control over the level of generality in which they choose to report event information. In the present study, we adopted an early-intervention approach to investigate to what extent eyewitness memory may be inoculated against suggestibility, following two different levels of interpolated reporting: verbatim and gist. After viewing a target event, participants responded to interpolated questions that required reporting of target details at either the verbatim or the gist level. After 48 hr, both groups of participants were misled about half of the target details and were finally tested for verbatim memory of all the details. The findings were consistent with our predictions: Whereas verbatim testing was successful in completely inoculating against suggestibility, gist testing did not reduce it whatsoever. These findings are particularly interesting in light of the comparable testing effects found for these two modes of interpolated testing.

Does reconsolidation occur in humans?

Evidence for reconsolidation in non-human animals has accumulated rapidly in the last decade, providing compelling` demonstration for this phenomenon across species and memory paradigms. In vast contrast, scant evidence exists for human reconsolidation to date. A major reason for this discrepancy is the invasive nature of current techniques used to investigate reconsolidation, which are difficult to apply in humans. Pharmacological blockade of reconsolidation, for example, has been typically used in animals as a proof of concept. However, most compounds used in these studies are toxic for humans, and those compounds that are safe target related, but not direct mechanisms of reconsolidation. Thus, although human reconsolidation has been hypothesized, there is limited evidence it actually exists. The best evidence for human reconsolidation emerges from non-invasive techniques that “update” memory during reconsolidation rather than block it, a technique only rarely used in animal research. Here we discuss the current state of human reconsolidation and the challenges ahead. We review findings on reconsolidation of emotional associative, episodic, and procedural memories, using invasive and non-invasive techniques. We discuss the possible interpretation of these results, attempt to reconcile some inconsistencies, and suggest a conceptual framework for future research.

False rumors and true belief: memory processes underlying children's errant reports of rumored events

Previous research has shown that overhearing an errant rumor--either from an adult or from peers--about an earlier experience can lead children to make detailed false reports. This study investigates the extent to which such accounts are driven by changes in children's memory representations or merely social demands that encourage the reporting of rumored information. This was accomplished by (a) using a warning manipulation that eliminated social pressures to report an earlier heard rumor and (b) examining the qualitative characteristics of children's false narratives of a rumored-but-nonexperienced event. Findings indicated that overheard rumors can induce sensory and contextual characteristics in memory that can lead children to develop genuine false beliefs in seeing rumored-but-nonexperienced occurrences. Such constructive tendencies were especially likely among 3- and 4-year-olds (relative to 5- and 6-year-olds) and when rumors were picked up from peers during natural social interactions (relative to when they were planted by an adult).

Source monitoring in eyewitness memory: implicit associations, suggestions, and episodic traces

Both the distinctiveness heuristic and discrepancy detection hypotheses were investigated by independently manipulating both schema consistency and incidental suggestion in an eyewitness memory paradigm. A sequence of slides was shown, followed by a postevent questionnaire that contained both schema-typical and schema-atypical information. Fifteen minutes later, a source-monitoring task was administered. In Experiment 1, the proportion of source misattribution errors was greater for schema-typical items than for schema-atypical items, and the proportion of errors on suggested items was greater than that on control items. Suggestion affected schema-typical and schema-atypical items equally, providing no support for the predictions of either hypothesis. In Experiment 2, the interval between the questionnaire and the source test was manipulated. The results of Experiment 1 were replicated under the short delay, whereas the proportion of errors increased under the long delay. An associative network model involving two types of episodic traces was used to account for the results.

Suggestibility, social support, and memory for a novel experience in young children

This study examined 5- and 6-year-olds' suggestibility and interviewer demeanor as joint predictors of their memory for a novel experience. Session 1 consisted of children taking part in a novel laboratory event. Session 2 took place after approximately a 1-week delay and consisted of children completing both a memory test concerning what happened during the prior event and the Video Suggestibility Scale for Children (VSSC). During the second session, the interviewer behaved either supportively or nonsupportively. Greater acquiescence on the VSSC was associated with fewer correct responses to misleading questions about the laboratory event in the supportive and nonsupportive conditions and with more errors in response to specific questions in the nonsupportive condition. Results indicate that individual differences in children's suggestibility are related to the accuracy of their memory for separate events, although some of these relations may vary depending on the context in which children are interviewed.

Reconceptualizing Children's Suggestibility: Bidirectional and Temporal Properties

Forty-one children (3 to 7 years) were exposed to a staged event and later interviewed by 1 of 41 professional interviewers. All interviews were coded with a detailed, mutually exclusive, and exhaustive coding scheme capturing adult behaviors (leading questions vs. neutral) and child behaviors (acquiescence vs. denial) in a temporally organized manner. Overall, interviewers' use of leading questions did not result in increased acquiescence as previously found. However, one specific type of leading question (i.e., inaccurate misleading) was followed by acquiescence. Lagged sequential analyses showed that it was possible to predict directly from child-to-child behavior, effectively skipping the intervening adult behavior. This result raises questions about the current conceptualization that suggestibility is driven by adult behaviors.

Which Route to Recovery?: Controlled Retrieval and Accessibility Bias in Retroactive Interference

New learning often interferes with the production of older, previously learned responses. However, the original responses usually appear to spontaneously recover and regain their dominance after a delay. This article takes a new approach to questions of interference and recovery by examining performance on immediate and delayed tests using direct or indirect instructions. Direct instructions asked participants to deliberately retrieve the original responses, and indirect instructions allowed them to respond on a more automatic basis, using whatever response came to mind first. Results suggest that interference and recovery may have their largest effects via relatively automatic influences on memory, such as the accessibility of new versus original information. This finding adds a new perspective to classic theories of interference and recovery, and may also inform current understanding of performance in populations (e.g., older adults) that often rely predominantly on automatic memory processing.

The cognitive neuroscience of constructive memory

Numerous empirical and theoretical observations point to the constructive nature of human memory. This paper reviews contemporary research pertaining to two major types of memory distortions that illustrate such constructive processes: (a) false recognition and (b) intrusions and confabulations. A general integrative framework that outlines the types of problems that the human memory system must solve in order to produce mainly accurate representations of past experience is first described. This constructive memory framework (CMF) emphasizes processes that operate at encoding (initially binding distributed features of an episode together as a coherent trace; ensuring sufficient pattern separation of similar episodes) and also at retrieval (formation of a sufficiently focused retrieval description with which to query memory; postretrieval monitoring and verification). The framework is applied to findings from four different areas of research: cognitive studies of young adults, neuropsychological investigations of brain-damaged patients, neuroimaging studies, and studies of cognitive aging.

The verbal overshadowing effect: why descriptions impair face recognition

Three experiments explored the verbal overshadowing effect, that is, the phenomenon that describing a previously seen face impairs recognition of this face. There were three main results: First, a verbal overshadowing effect was obtained both when subjects were provided with and when they generated a description of an earlier seen face. Second, instructing subjects at the time of test to be aware of potentially competing memories did not improve, and may even have worsened, recognition performance when the subjects had generated a description of the target face. However, these instructions improved performance and eliminated the verbal overshadowing effect when subjects were provided with someone else's description of the target face. Third, recognition of the target face was disrupted when subjects described a completely different face, such as their parent's face or a face of the opposite sex. The results are discussed in relation to two potential mechanisms: source confusion between previously encoded visual and verbal representations of the face and a shift in processing of the test faces at recognition.

"I hardly cried when I got my shot!" Influencing children's reports about a visit to their pediatrician

We examined, in 2 phases, the influence of postevent suggestions on children's reports of their visits to a pediatrician. Phase 1 examined the effect of giving one of 3 types of feedback to 5-year-old children immediately following their Diphtheria Pertussis Tetanus (DPT) inoculation. Children were given pain-affirming feedback (the shot hurt), pain-denying feedback (the shot did not hurt), or neutral feedback (the shot is over). 1 week later, they did not differ in their reports concerning how much the shot hurt or how much they cried. In Phase 2, the same children were visited approximately 1 year after their inoculation. During 3 separate visits, they were either given additional pain-denying or neutral feedback. They were also given misleading or nonmisleading information about the actions of the pediatrician and the assistant. Children given pain-denying feedback reported that they cried less and that the shot hurt less than did children given neutral feedback. Those who were given misleading information about the actions of the assistant and the pediatrician made more false allegations about their actions than did children who were not given this information. These results challenge the view that suggestibility effects are confined to peripheral, nonaction events; in this study children's reports about salient actions involving their own bodies in stressful conditions were influenced.

Memory impairment and source misattribution in postevent misinformation experiments with short retention intervals

The four experiments reported here provide evidence that (1) misleading postevent suggestions can impair memory for details in a witnessed event and (2) subjects sometimes remember suggested details as things seen in the event itself. All four experiments used recall tests in which subjects were warned of the possibility that the postevent information included misleading suggestions and were instructed to report both what they witnessed in the event and what was mentioned in the postevent narrative. Recall of event details was poorer on misled items than on control items, and subjects sometimes misidentified the sources of their recollections. Our results suggest that these findings are not due to guessing or response biases, but rather reflect genuine memory impairment and source monitoring confusions.