Abducted by a UFO: prevalence information affects young children's false memories for an implausible event

Implanting rich autobiographical false memories: Meta-analysis for forensic practice and judicial judgment making

Objective

The implanting of rich autobiographical false memories is crucial for judicial decision-making, and the forensic evaluation of a testimony. In order to assess this issue, a meta-analytical review of the probability of implanting rich autobiographical false memories was performed.

Method

A total of 30 primary studies analysing the probability of implanting rich autobiographical false memories were retrieved. Random-effects meta-analyses correcting the effect size for sampling error were performed.

Results

The results revealed a significant, positive, generalizable (the lower limit for the 80% credibility value was d = 1.13), and more than large mean effect size (d = 1.43[1.33, 1.53]) for the implanting of false memory. The moderating effects of stimulus type showed that the effect of the probability of implanted false memory was significantly higher in experienced events (d = 2.03[1.63, 2.43]) than in false narratives (d = 1.35[1.23, 1.47]), and in doctored photographs (d = 1.29[1.06, 1.52]). A similar effect for memory implantation was observed in both the underage (d = 1.44[1.29, 1.59]), and in adults (d = 1.36[1.22, 1.50]). The moderator techniques for implanting false memories revealed a significantly lower probability of implanting false rich memory with non-directive instructions (d = 0.90[0.53, 1.27]) than with guided imagery (d = 1.45[1.32, 1.58]), or with pressure to answer (d = 1.56[1.17, 1.95]) instructions. The event emotional valence moderator exhibited the same effect for positive (d = 1.27[1.09, 1.45]) and negative valence events (d = 1.30[1.17, 1.43]).

Conclusions

The implications of the results for forensic testimony evaluation, police interrogations, and judicial cross-examination are discussed.

Lost in the mall again: a preregistered replication and extension of Loftus & Pickrell (1995)

The seminal Lost in the Mall study has been enormously influential in psychology and is still cited in legal cases. The current study directly replicated this paper, addressing methodological weaknesses including increasing the sample size fivefold and preregistering detailed analysis plans. Participants (N = 123) completed a survey and two interviews where they discussed real and fabricated childhood events, based on information provided by an older relative. We replicated the findings of the original study, coding 35% of participants as reporting a false memory for getting lost in a mall in childhood (compared to 25% in the original study). In an extension, we found that participants self-reported high rates of memories and beliefs for the fabricated event. Mock jurors were also highly likely to believe the fabricated event had occurred and that the participant was truly remembering the event, supporting the conclusions of the original study.

What happens after debriefing? The effectiveness and benefits of postexperimental debriefing

After participating in an experiment, people are routinely debriefed. How effective is debriefing when the experiments involve deception, as occurs in studies of misinformation and memory? We conducted two studies addressing this question. In Study 1, participants (N = 373) watched a video, were exposed to misinformation or not, and completed a memory test. Participants were either debriefed or not and then were interviewed approximately one week later. Results revealed that, after debriefing, some participants continued to endorse misinformation. Notably, however, debriefing had positive effects; participants exposed to misinformation reported learning significantly more from their study participation than control participants. In Study 2 (N = 439), we developed and tested a novel, enhanced debriefing. The enhanced debriefing included more information about the presence of misinformation in the study and how memory errors occur. This enhanced debriefing outperformed typical debriefing. Specifically, when the enhanced debriefing explicitly named and described the misinformation, the misinformation effect postdebriefing was eliminated. Enhanced debriefing also resulted in a more positive participant experience than typical debriefing. These results have implications for the design and use of debriefing in deception studies.

Rich false memories of autobiographical events can be reversed

False memories of autobiographical events can create enormous problems in forensic settings (e.g., false accusations). While multiple studies succeeded in inducing false memories in interview settings, we present research trying to reverse this effect (and thereby reduce the potential damage) by means of two ecologically valid strategies. We first successfully implanted false memories for two plausible autobiographical events (suggested by the students' parents, alongside two true events). Over three repeated interviews, participants developed false memories (measured by state-of-the-art coding) of the suggested events under minimally suggestive conditions (27%) and even more so using massive suggestion (56%). We then used two techniques to reduce false memory endorsement, source sensitization (alerting interviewees to possible external sources of the memories, e.g., family narratives) and false memory sensitization (raising the possibility of false memories being inadvertently created in memory interviews, delivered by a new interviewer). This reversed the false memory build-up over the first three interviews, returning false memory rates in both suggestion conditions to the baseline levels of the first interview (i.e., to ∼15% and ∼25%, respectively). By comparison, true event memories were endorsed at a higher level overall and less affected by either the repeated interviews or the sensitization techniques. In a 1-y follow-up (after the original interviews and debriefing), false memory rates further dropped to 5%, and participants overwhelmingly rejected the false events. One strong practical implication is that false memories can be substantially reduced by easy-to-implement techniques without causing collateral damage to true memories.

Hazy memories in the courtroom: A review of alcohol and other drug effects on false memory and suggestibility

Alcohol and other psychoactive drugs are oftentimes implicated in legal cases. A pertinent question herein is whether such substances might adversely affect testimonies of victims, eyewitnesses, or suspects by propelling the formation of false memory and increasing susceptibility to suggestion. In the current review, we amassed all available evidence on the effects of intoxication on false memory formation and suggestibility, including the substances alcohol, benzodiazepines, cannabis, stimulants, hallucinogens, and antipsychotics. Our review indicated that alcohol and cannabis under certain conditions increased the susceptibility to false memories and/or suggestion with effect sizes ranging from medium to large. When intoxicated during an event, alcohol is most likely to increase this susceptibility at high intoxication levels or after a delay, whereas cannabis exerts detrimental effects during acute intoxication but not necessarily once sober. For other substances, ecologically valid research separating different memory phases is needed. Overall, differences between substances regarding false memory effects exist, suggesting that a nuanced approach is needed when dealing with intoxicated individuals in a legal context.

What science tells us about false and repressed memories

What does science tell us about memory phenomena such as false and repressed memories? This issue is highly pressing as incorrect knowledge about these memory phenomena might contribute to egregious effects in the courtroom such as false accusations of abuse. In the current article, we provide a succinct review of the scientific nature of false and repressed memories. We demonstrate that research has shown that about 30% of tested subjects formed false memories of autobiographical experiences. Furthermore, this empirical work has also revealed that such false memories can even be implanted for negative events and events that allegedly occurred repeatedly. Concerning the controversial topic of repressed memories, we show that plausible alternative explanations exist for why people claim to have forgotten traumatic experiences; explanations that do not require special memory mechanisms such as the unconscious blockage of traumatic memories. Finally, we demonstrate that people continue to believe that unconscious repression of traumatic incidents can exist. Disseminating scientifically articulated knowledge on the functioning of memory to contexts such as the courtroom is necessary as to prevent the occurrence of false accusations and miscarriages of justice.

Fool me twice: how effective is debriefing in false memory studies?

Deception is often necessary in false memory studies, especially when the study aims to explore the effect of misinformation on memory. At the end of the study, participants are debriefed, but does this eliminate the influence of misinformation? In the current study, we followed up 630 participants six months after they participated in a study in which they were exposed to fabricated political news stories. We compared the memories of these "continuing participants" for both novel and previously seen news stories to the memories of 474 newly recruited participants. Relative to new recruits, continuing participants were less likely to report a false memory for a story that they had been previously exposed to, and they were also less likely to report a false memory for a novel fake news story. Continuing participants were more likely to report a memory for previously seen true events than novel true events. Both groups of participants reported enjoying the experience and feeling confident that they understood which stories were fabricated. Importantly, this study did not find any negative long-term effects of participating in our false memory experiment, and even exhibited some positive effects.

Believing does not equal remembering: The effects of social feedback and objective false evidence on belief in occurrence, belief in accuracy, and recollection

We examined the impact of social feedback and objective false evidence on belief in occurrence, belief in accuracy, and recollection of an autobiographical experience. Participants viewed six virtual scenes (e.g., park) and were tested on their belief/recollection. After 1-week, participants were randomly assigned to four groups. One group received social feedback that one scene was not experienced. A second group received objective false evidence that one of the scenes was not shown. A third group received both social feedback and objective false evidence and the control group did not receive any manipulation. Belief in occurrence dropped considerably in the social feedback group and in the combined group. Also, nonbelieved memories were most likely to occur in participants receiving both social feedback and objective false evidence. We show that social feedback and objective false evidence undermine belief in occurrence, but that they leave belief in accuracy and recollection unaffected.

Who Is the Better Eyewitness? Sometimes Adults but at Other Times Children

Suggestibility is regarded as a major issue when children testify in court. Many legal professionals and memory researchers view children as inferior witnesses. Although differences in suggestibility exist between children and adults, they are much more complex than is usually assumed. We show that under certain conditions, adults are more susceptible than children to suggestion and false memories. We provide evidence that age-related shifts in suggestibility and false memory appear contingent on how quickly and automatically children and adults make associations when experiencing events. Specifically, when confronted with suggestive information about a related but nonexperienced detail, adults more frequently automatically generate links between items experienced and those already in memory, making them more susceptible to suggestion than children.

Positive events protect children from causal false memories for scripted events

Adults produce fewer inferential false memories for scripted events when their conclusions are emotionally charged than when they are neutral, but it is not clear whether the same effect is also found in children. In the present study, we examined this issue in a sample of 132 children aged 6-12 years (mean 9 years, 3 months). Participants encoded photographs depicting six script-like events that had a positively, negatively, or a neutral valenced ending. Subsequently, true and false recognition memory of photographs related to the observed scripts was tested as a function of emotionality. Causal errors-a type of false memory thought to stem from inferential processes-were found to be affected by valence: children made fewer causal errors for positive than for neutral or negative events. Hypotheses are proposed on why adults were found protected against inferential false memories not only by positive (as for children) but also by negative endings when administered similar versions of the same paradigm.

A Case Concerning Children's False Memories of Abuse: Recommendations Regarding Expert Witness Work

Expert witnesses can play a major role in legal cases concerning the reliability of statements. Abuse cases frequently contain only the memories of eyewitnesses/victims without the presence of physical evidence. Here, it is of the utmost importance that expert witnesses use scientific evidence for their expert opinion. In this case report, a case is described in which 20 children reported being sexually abused by the same teachers at their elementary school. The investigative steps that were taken by the police and school authorities are reviewed, including how they probably affected memory. In order to provide a sound expert opinion regarding the reliability of these statements, three recommendations are proposed. To reduce the effect of confirmation bias and increase objectivity, it is argued that expert witnesses' reports should contain alternative scenarios, be checked by another expert, and focus on the origin and context of the first statement.

Developmental Differences across Middle Childhood in Memory and Suggestibility for Negative and Positive Events

In the present study, we investigated age differences in children's eyewitness memory and suggestibility for negative and positive events that children often experience during middle childhood. We first examined 216 ratings by children aged 8-12 years of the frequency and intensity of personal negative and positive experiences (Study 1). Based on those ratings, videotapes depicting the most frequent and intense negative (an accident) and positive (a family excursion) events were developed. A new sample of 227 children aged 8-12 years was tested for recognition memory of the videotapes using the three-stage post-event misinformation procedure (Study 2). Compared with 8- to 9-year-olds, 10- to 12-year-olds exhibited less memory malleability and less compliance with false information. Age improvements in recognition accuracy were also evident for children who watched the negative event, but not for those who watched the positive event. Compliance predicted misinformation effects, particularly in regard to peripheral details. Thus, using ecologically representative emotional events, age differences in suggestibility and memory accuracy emerged, especially for negative events.Theoretical and forensic implications concerning children's eyewitness memory and suggestibility are discussed. Copyright © 2016 John Wiley & Sons, Ltd.

On the adaptive function of children's and adults' false memories

Recent research has shown that memory illusions can successfully prime both children's and adults' performance on complex, insight-based problems (compound remote associates tasks or CRATs). The current research aimed to clarify the locus of these priming effects. Like before, Deese–Roediger–McDermott (DRM) lists were selected to prime subsequent CRATs such that the critical lures were also the solution words to a subset of the CRATs participants attempted to solve. Unique to the present research, recognition memory tests were used and participants were either primed during the list study phase, during the memory test phase, or both. Across two experiments, primed problems were solved more frequently and significantly faster than unprimed problems. Moreover, when participants were primed during the list study phase, subsequent solution times and rates were considerably superior to those produced by those participants who were simply primed at test. Together, these are the first results to show that false-memory priming during encoding facilitates problem-solving in both children and adults.

Occurrence, plausibility, and desirability for 124 Life Events Inventory items

Imagination inflation is where imaginative elaboration of possible childhood experiences inflates (increases) participants' estimation that these events actually occurred, as indicated by pre- to post-manipulation ratings changes. This research primarily uses the Life Events Inventory (LEI), listing possible experiences that could have happened during childhood (Garry, Manning, Loftus, & Sherman, Psychonomic Bulletin & Review, 3, 208-214, 1996). Although imagination inflation research has spawned more than 50 investigations, no normative ratings exist on individual items contained in the LEI. To address this, we present descriptive statistics (mean, median, standard deviation, confidence interval) for 124 LEI items on occurrence (how likely is it that this experience happened to you), plausibility (how plausible is it that this event could have happened to someone), and desirability (how desirable is this experience). Occurrence and plausibility showed similar patterns of mean item ratings and were highly correlated, whereas desirability was moderately correlated with plausibility and unrelated to occurrence. These data should facilitate a more informed selection of specific LEI items to use in further research and can assist in clarifying the contributions of normative occurrence, plausibility, and desirability to imagination inflation effects.

Developmental trends in different types of spontaneous false memories: implications for the legal field

In an emerging area of memory research, it is becoming apparent that one particular type of false memory, called spontaneous false memory, follows a developmental trajectory that is the opposite of what is commonly assumed in false memory research - that is, spontaneous false memories are more likely to occur in adults than in children. The present study focused on developmental trends of different types of spontaneous false memories. Specifically, in the current study, 6-8 year-olds, 10-12 year-olds, and adults were presented with two methods to induce spontaneous false memories: (i) semantically related word lists that are commonly used to evoke spontaneous false memories [i.e, Deese-Roediger-McDermott (DRM) paradigm]; and (ii) a video in which related details were not shown but were presented during a recognition task. The results showed that children were more likely to form false memories than adults in the video false memory paradigm, whereas DRM false memories were more evident in adults than in children. Furthermore, we found that on a general level, DRM false memories were positively related to video spontaneous false memories. We explain that stimuli that contain obvious themes attenuate or even reverse developmental trends in spontaneous false memories.

Novel shifts in memory research and their impact on the legal process: introduction to the special issue on memory formation and suggestibility in the legal process

The functioning and frailties of memory are frequently at the centerpiece of much expert testimony about the reliability of eyewitness accounts. Although we have much knowledge about how false memories and suggestibility can affect testimonies, the contributions in this special issue show that when using a sound theoretical framework, novel directions in this field can surface. The papers in this issue can broadly be divided into contributions that are related to: (1) the exact determinants of false memory and suggestibility; (2) new paradigms in legal psychology; (3) positive consequences of memory illusions; and (4) developmental false memory research. Collectively, these contributions have the potential to provide novel shifts in memory research and push this field beyond its current boundaries.

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.

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.

The origin of children's implanted false memories: memory traces or compliance?

A longstanding question in false memory research is whether children's implanted false memories represent actual memory traces or merely result from compliance. The current study examined this question using a response latency based deception task. Forty-five 8-year-old children received narratives about a true (first day at school) and false event (hot air balloon ride). Across two interviews, 58/32% of the participants developed a partial/full false memory. Interestingly, these children also showed higher false recall on an unrelated DRM paradigm compared to children without a false memory. The crucial finding, however, was that the results of the deception task revealed that children with partial and full false memories were faster to confirm than to deny statements relating to the false event. This indicates that children's implanted false memories reflect actual memory traces, and are unlikely to be explained by mere compliance.

Script knowledge enhances the development of children's false memories

We examined whether script knowledge contributes to the development of children's false memories. Sixty 7-year-old and 60 11-year-old children listened to false narratives describing either a high-knowledge event (i.e., fingers being caught in a mousetrap) or a low-knowledge event (i.e., receiving a rectal enema) that were similar in terms of plausibility and pleasantness. Moreover, half of the children in each condition received additional suggestive details about the false events. Across two interviews, children had to report everything they remembered about the events. Script knowledge affected children's false memories in that both younger and older children developed more false memories for the high-knowledge event than for the low-knowledge event. Moreover, at the first interview, additional suggestive details inhibited the development of children's images into false memories.

Children's suggestion-induced omission errors are not caused by memory erasure

We explored whether children's suggestion-induced omission errors are caused by memory erasure. Seventy-five children were instructed to remove three pieces of clothing from a puppet. Next, they were confronted with evidence falsely suggesting that one of the items had not been removed. During two subsequent interviews separated by one week, children had to report which pieces of clothing they had removed. Children who during both interviews failed to report that they had removed the pertinent item (i.e., omission error; n=24) completed a choice reaction time task. In this task, they were presented with different clothing items. For each item, children had to indicate whether or not they had removed it. Significantly more errors were made for those removed items that children failed to report than for those they had not removed. This indicates that children's suggestion-based omission errors are not due to erasure of memories.

Children's false memories: easier to elicit for a negative than for a neutral event

The present study examined the role of valence in the development of children's implanted false memories. Seventy-six 7-year-old children listened to two true and one false narrative. The false narrative was either neutral ("moving to another classroom") or emotional negative ("being accused by the teacher for copying off your neighbor"). In addition, half of the children were presented with their class photograph while listening to the narratives. During two interviews, children recalled as many details as possible from the true and false events. Results showed that the negative event elicited more false memories than the neutral event. The presentation of a true photograph did not promote the development of false memories.