False claims about false memory research

False memories in cuttlefish

Episodic memory is a reconstructive process per se: during an event, the features composing it are encoded and stored separately in the brain, then reconstructed when the event's memory is retrieved. Even with source monitoring processes (e.g., did I see or did I smell it?), some mistakes can occur. These mnemonic mistakes happen especially when different events share several features, producing overlaps difficult to discriminate, leading to the creation of false memories. The common cuttlefish has the ability to remember specific events about what happened where and when, namely episodic-like memory. In order to investigate whether this memory, such as human episodic memory, is based on reconstructive processes, we elaborated a protocol promoting false memory formation. Our results suggest that cuttlefish do form visual false memories, but not olfactory false memories. These memory errors might be the first indication of the presence of reconstructive processes in the memory of cephalopods.

Proneness to false memory generation predicts pseudoscientific belief endorsement

Among cognitive factors that can influence the endorsement of pseudoscientific beliefs, our study focuses on proneness to false memory generation. In this preregistered study, we presented 170 fluent English speakers residing in the USA with a misinformation task aimed at generating false memories. In this task, they first completed an event encoding stage, in which two events were narrated through sequentially presented pictures. One day later, they read a series of sentences relating the same events but which included several inaccurate descriptions aimed at producing a misinformation effect. Finally, we measured the influence of the misinformation manipulation over false memory generation. After completing the misinformation task, participants responded to a questionnaire measuring pseudoscientific beliefs. Our results showed a positive correlation between pseudoscience endorsement and false memory rates, which indicates that the latter might be a key factor influencing susceptibility to pseudoscience. To our knowledge, this is the first study showing a link between the tendency to believe in pseudoscience and variability regarding proneness to develop false memories. Practical implications for the design of new interventions to effectively reduce pseudoscientific beliefs and their negative impact on our society are discussed.

Highly Superior Autobiographical Memory (HSAM): A Systematic Review

Individuals possessing a Highly Superior Autobiographical Memory (HSAM) demonstrate an exceptional ability to recall their own past, excelling most when dates from their lifetime are used as retrieval cues. Fully understanding how neurocognitive mechanisms support exceptional memory could lead to benefits in areas of healthcare in which memory plays a central role and in legal fields reliant on witnesses' memories. Predominantly due to the rareness of the phenomenon, existing HSAM literature is highly heterogenous in its methodologies used. Therefore, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we performed the first systematic review on this topic, to collate the existing behavioural, neuroanatomical, and functional HSAM data. Results from the 20 experimental selected studies revealed that HSAM is categorised by rapidly retrieved, detailed and accurate autobiographical memories, and appears to avoid the normal aging process. Functional neuroimaging studies showed HSAM retrieval seems characterised by an intense overactivation of the usual autobiographical memory network, including posterior visual areas (e.g., the precuneus). Structural neuroanatomical differences do not appear to characterise HSAM, but altered hippocampal resting-state connectivity was commonly observed. We discuss theories of HSAM in relation to autobiographical encoding, consolidation, and retrieval, and suggest future directions for this research.

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.

How to optimize knowledge construction in the brain

Well-structured knowledge allows us to quickly understand the world around us and make informed decisions to adequately control behavior. Knowledge structures, or schemas, are presumed to aid memory encoding and consolidation of new experiences so we cannot only remember the past, but also guide behavior in the present and predict the future. However, very strong schemas can also lead to unwanted side effects such as false memories and misconceptions. To overcome this overreliance on a schema, we should aim to create robust schemas that are on the one hand strong enough to help to remember and predict, but also malleable enough to avoid such undesirable side effects. This raises the question as to whether there are ways to deliberately influence knowledge construction processes, with the goal to reach such optimally balanced schemas. Here, we will discuss how the mnemonic processes in our brains build long-term knowledge and, more specifically, how different phases of memory formation (encoding, consolidation, retrieval, and reconsolidation) contribute to this schema build-up. We finally provide ways how to best keep a balance between generalized semantic and detailed episodic memories, which can prove very useful in, e.g., educational settings.

Increases of correct memories and spontaneous false memories due to eye movements when memories are retrieved after a time delay

Eye Movement Desensitization and Reprocessing (EMDR) is an effective treatment for post-traumatic stress disorder. However, literature on possible adverse memory effects of EMDR is scarce. Using the Deese/Roediger-McDermott (DRM) false memory paradigm, we examined the susceptibility to spontaneous false memories after performing eye movements, as used in EMDR. In Experiment 1, 72 undergraduates received word lists containing negative and neutral associated words and immediately after this they were given a free recall and recognition test. In Experiment 2, 68 undergraduates underwent the free recall and recognition test 48 h later. During the free recall phase in both experiments, participants either performed eye movements or not (control condition). In Experiment 1, the two conditions did not differ statistically with regard to correct and false recall/recognition. In Experiment 2, correct memory rates were higher in the eye movement than in the control condition and this was accompanied by an increase in spontaneous false memories on both free recall and recognition. Although our experimental approach is far removed from clinical practice, our findings suggest that eye movements as used in EMDR might amplify both correct and false memory rates.

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.

When a child dies of heatstroke after a parent or caretaker unknowingly leaves the child in a car: How does it happen and is it a crime?

It is commonly reported that in the course of a drive, a parent or caretaker loses awareness of the presence of a child in the back seat of the car. Upon arriving at the destination, the driver exits the car and unknowingly leaves the child in the car. This incomprehensible lapse of memory exposes forgotten children to hazards, including death from heatstroke. More than 400 children in the past 20 years have suffered from heatstroke after being unknowingly forgotten in cars. How can loving and attentive parents, with no evidence of substance abuse or an organic brain disorder, have a catastrophic lapse of memory that places a child's welfare in jeopardy? This article addresses this question at multiple levels of analysis. First, it is concluded that the loss of awareness of a child in a car is a failure of a type of memory referred to as prospective memory (PM), that is, failure to remember to execute a plan in the future. Second, factors that increase the likelihood that PM will fail are identified. Third, research on the neurobiology of PM and PM-related memory failures are reviewed, including a discussion of how competition between brain structures contributes to a failure of PM. Finally, the issue of whether a failure of PM that results in harm to a child qualifies as a criminal offence is discussed. Overall, this neuropsychological perspective on how catastrophic memory errors occur should be of value to the scientific community, the public and law-enforcement agencies.

State-Dependent Memory: Neurobiological Advances and Prospects for Translation to Dissociative Amnesia

In susceptible individuals, overwhelming traumatic stress often results in severe abnormalities of memory processing, manifested either as the uncontrollable emergence of memories (flashbacks) or as an inability to remember events (dissociative amnesia, DA) that are usually, but not necessarily, related to the stressful experience. These memory abnormalities are often the source of debilitating psychopathologies such as anxiety, depression and social dysfunction. The question of why memory for some traumatic experiences is compromised while other comparably traumatic experiences are remembered perfectly well, both within and across individuals, has puzzled clinicians for decades. In this article, we present clinical, cognitive, and neurobiological perspectives on memory research relevant to DA. In particular, we examine the role of state dependent memory (wherein memories are difficult to recall unless the conditions at encoding and recall are similar), and discuss how advances in the neurobiology of state-dependent memory (SDM) gleaned from animal studies might be translated to humans.

Everyday false memories in older persons with depressive disorder

Generally we tend to think that memory in daily living is complete and accurate in healthy persons. However, current memory research has revealed inconspicuous memory faults. Rarely omissions and distortions of memory are researched with tasks resembling everyday life. We investigated healthy older control subjects (HC) and patients with depressive disorder (DD). Cognitive function was assessed with a comprehensive neuropsychological test battery and mood with the Montgomery-Asberg Depression Scale (MADRS). We assessed everyday veridical and distorted memories on showing participants original news and commercials. In most aspects of attention, executive functions, and memory, patients with DD performed worse than HC. Regarding memory content on viewing news or commercials the difference between patients with DD and HC was more pronounced for false memory content than for veridical memory content. Linear regression analysis showed the extent of false memory content being associated with mental flexibility as assessed with the Trail Making Test and mood as assessed with the MADRS for both information obtained on viewing news and commercials. Increase of false memories impedes overall accuracy of memory more than decrease of veridical memories in older persons with depressive disorder. Diminished executive functions and depressive mood partly explain these memory distortions.

On the advantage of autobiographical memory pliability: implantation of positive self-defining memories reduces trait anxiety

This paper is devoted to the mechanism of the positive construction of autobiographical memory. Positive construction consists of the spontaneous transformation of memories in the direction of the subjective enhancement of self-competence in past activities to anticipate improvement over time. We speculated that trait anxiety may indicate a failure to exhibit this mechanism that results in a deficit of affirmative self-esteem. We hypothesised that the implantation of positive self-defining memories in anxiety-evoking domains would decrease trait anxiety. One hundred twenty adults recollected three negative self-defining memories. Then, half of the participants imagined episodes of desired behaviour that differed from the originally recollected ones either in discussion or in hypnosis. Thirty participants experienced a hypnotic state without any references to memories, and the rest formed the control group. Subjects from the "Memory Implantation in Hypnosis" group became unable to distinguish the originally reported memories from the imagined ones, exhibited decreased trait anxiety scores after a 4-month delay, and reported enhanced self-esteem. In contrast, the participants from the "Hypnosis with no reference to the past" group exhibited decreased scores at a short delay but later returned to their original scores. These findings highlight the power of cured episodic-like autobiographical memory for updating the self.

What Drives False Memories in Psychopathology? A Case for Associative Activation

In clinical and court settings, it is imperative to know whether posttraumatic stress disorder (PTSD) and depression may make people susceptible to false memories. We conducted a review of the literature on false memory effects in participants with PTSD, a history of trauma, or depression. When emotional associative material was presented to these groups, their levels of false memory were raised relative to those in relevant comparison groups. This difference did not consistently emerge when neutral or nonassociative material was presented. Our conclusion is supported by a quantitative comparison of effect sizes between studies using emotional associative or neutral, nonassociative material. Our review suggests that individuals with PTSD, a history of trauma, or depression are at risk for producing false memories when they are exposed to information that is related to their knowledge base.

Maltreatment increases spontaneous false memories but decreases suggestion-induced false memories in children

We examined the creation of spontaneous and suggestion‐induced false memories in maltreated and non‐maltreated children. Maltreated and non‐maltreated children were involved in a Deese–Roediger–McDermott false memory paradigm where they studied and remembered negative and neutral word lists. Suggestion‐induced false memories were created using a misinformation procedure during which both maltreated and non‐maltreated children viewed a negative video (i.e., bank robbery) and later received suggestive misinformation concerning the event. Our results showed that maltreated children had higher levels of spontaneous negative false memories but lower levels of suggestion‐induced false memories as compared to non‐maltreated children. Collectively, our study demonstrates that maltreatment both increases and decreases susceptibility to memory illusions depending on the type of false memory being induced.

Exploring the consequences of nonbelieved memories in the DRM paradigm

In the current experiments, we attempted to elicit nonbelieved memories (NBMs) using the Deese/Roediger-McDermott (DRM) false memory paradigm. Furthermore, by using this approach, we explored the consequences of nonbelieved true and false memories. In Experiments 1 and 2, participants received several DRM wordlists and were presented with a recognition task. After the recognition task, participants' statements were contradicted by giving them feedback about true and false items. In this way, we succeeded in eliciting nonbelieved true and false memories. In Experiment 2, participants were also involved in a modified perceptual closure task after receiving belief-relevant feedback. In this task, participants received degraded visual representations of words (e.g., false and true) that became clearer over time. Participants had to identify them as fast as possible. We also measured dissociation, compliance, and social desirability. We found that undermining belief had contrasting consequences for true and false memories. That is, nonbelieved true memories were identified more slowly whereas nonbelieved false memories were identified more quickly. We did not find any relation between our individual differences measures and the formation of NBMs.

Cortisol response and psychological distress predict susceptibility to false memories for a trauma film

For eyewitness testimony to be considered reliable, it is important to ensure memory remains accurate following the event. As many testimonies involve traumatic, as opposed to neutral, events, it is important to consider the role of distress in susceptibility to false memories. The aim of this study was to investigate whether cortisol response following a stressor would be associated with susceptibility to false memories. Psychological distress responses were also investigated, specifically, dissociation, intrusions, and avoidance. Participants were allocated to one of three conditions: those who viewed a neutral film (N = 35), those who viewed a real trauma film (N = 35), and a trauma "reappraisal" group where participants were told the film was not real (N = 35). All received misinformation about the film in the form of a narrative. Participants provided saliva samples (to assess cortisol) and completed distress and memory questionnaires. Cortisol response was a significant predictor of the misinformation effect. Dissociation and avoidance were related to confabulations. In conclusion, following a stressor an individual may differ with regard to their psychological response to the event, and also whether they experience a cortisol increase. This may affect whether they are more distressed later on, and also whether they remember the event accurately.

The misinformation effect is unrelated to the DRM effect with and without a DRM warning

The misinformation and Deese-Roediger-McDermott (DRM) paradigms are used to study forms of false memories. Despite the abundance of research using these two paradigms, few studies have examined the relationship between the errors that arise from them. In the present study, 160 participants completed a misinformation task and two DRM tasks, receiving a warning about the effect before the second DRM task. Participants demonstrated misinformation and DRM effects (with and without the warning), but susceptibility to these forms of false memory were not significantly related across individuals. The DRM warning reduced the DRM effect, and signal detection analysis revealed that the DRM warning reduced a liberal response bias in this task. Sensitivity and response bias in both DRM tasks were not significantly related to these measures in the misinformation task. These findings suggest that these two forms of false memories are not interchangeable and they appear to be the result of different cognitive processes.

Sleep Deprivation and False Memories

Many studies have investigated factors that affect susceptibility to false memories. However, few have investigated the role of sleep deprivation in the formation of false memories, despite overwhelming evidence that sleep deprivation impairs cognitive function. We examined the relationship between self-reported sleep duration and false memories and the effect of 24 hr of total sleep deprivation on susceptibility to false memories. We found that under certain conditions, sleep deprivation can increase the risk of developing false memories. Specifically, sleep deprivation increased false memories in a misinformation task when participants were sleep deprived during event encoding, but did not have a significant effect when the deprivation occurred after event encoding. These experiments are the first to investigate the effect of sleep deprivation on susceptibility to false memories, which can have dire consequences.

The relationship between DRM and misinformation false memories

This research investigated the relationship between false memories induced by two different paradigms (misinformation and Deese-Roediger-McDermott [DRM]). The misinformation effect refers to the phenomenon that a person's recollection of a witnessed event can be altered after exposure to misleading information about the event. DRM false memory represents the intrusion of words that are semantically related but not actually presented in the study session. Subjects (N = 432) completed both misinformation and DRM false memory tests. Results showed a small but significant correlation (r = .12, p = .02) between the misinformation and DRM false memories. Furthermore, using signal detection theory, we found that the discrimination ability index (d') was related to both the misinformation and DRM false memories (r = -.12 and -.13, p = .01), while the response bias was related only to DRM false memory (r = -.46, p < .001). These results suggest that misinformation and DRM false memories generally involve different mechanisms and that their shared mechanism may involve the global discrimination ability.

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.

False memory ≠ false memory: DRM errors are unrelated to the misinformation effect

The DRM method has proved to be a popular and powerful, if controversial, way to study 'false memories'. One reason for the controversy is that the extent to which the DRM effect generalises to other kinds of memory error has been neither satisfactorily established nor subject to much empirical attention. In the present paper we contribute data to this ongoing debate. One hundred and twenty participants took part in a standard misinformation effect experiment, in which they watched some CCTV footage, were exposed to misleading post-event information about events depicted in the footage, and then completed free recall and recognition tests. Participants also completed a DRM test as an ostensibly unrelated filler task. Despite obtaining robust misinformation and DRM effects, there were no correlations between a broad range of misinformation and DRM effect measures (mean r  = -.01). This was not due to reliability issues with our measures or a lack of power. Thus DRM 'false memories' and misinformation effect 'false memories' do not appear to be equivalent.

Epilogue: continuing points of contention in the recovered memory debate

Four contentious issues in the recovered memory debate are explored. Volume contributors offer differing perspectives on the generalizability of laboratory research, on the role of emotion in memory, on the prevalence of false recoveries, and on the motivations that underlie differences in opinion, especially with regard to whether the debate ought to be framed within a larger sociopolitical context. The recovered memory debate is argued to center on two ethical concerns that happen to be in conflict, equality among groups on one hand and due process protections on the other. Additional movement toward reconciliation is possible with a fair assessment of all available evidence, with a mutual understanding of differing perspectives, and with civil discourse.

Individual differences in false memory from misinformation: cognitive factors

This research investigated the cognitive correlates of false memories that are induced by the misinformation paradigm. A large sample of Chinese college students (N=436) participated in a misinformation procedure and also took a battery of cognitive tests. Results revealed sizable and systematic individual differences in false memory arising from exposure to misinformation. False memories were significantly and negatively correlated with measures of intelligence (measured with Raven's Advanced Progressive Matrices and Wechsler Adult Intelligence Scale), perception (Motor-Free Visual Perception Test, Change Blindness, and Tone Discrimination), memory (Wechsler Memory Scales and 2-back Working Memory tasks), and face judgement (Face Recognition and Facial Expression Recognition). These findings suggest that people with relatively low intelligence and poor perceptual abilities might be more susceptible to the misinformation effect.

Valence and the development of immediate and long-term false memory illusions

Across five experiments we examined the role of valence in children's and adults' true and false memories. Using the Deese/Roediger-McDermott paradigm and either neutral or negative-emotional lists, both adults' (Experiment 1) and children's (Experiment 2) true recall and recognition was better for neutral than negative items, and although false recall was also higher for neutral items, false recognition was higher for negative items. The last three experiments examined adults' (Experiment 3) and children's (Experiments 4 and 5) 1-week long-term recognition of neutral and negative-emotional information. The results replicated the immediate recall and recognition findings from the first two experiments. More important, these experiments showed that although true recognition decreased over the 1-week interval, false recognition of neutral items remained unchanged whereas false recognition of negative-emotional items increased. These findings are discussed in terms of theories of emotion and memory as well as their forensic implications.

Anchoring effects in the development of false childhood memories

When people receive descriptions or doctored photos of events that never happened, they often come to remember those events. But if people receive both a description and a doctored photo, does the order in which they receive the information matter? We asked people to consider a description and a doctored photograph of a childhood hot air balloon ride, and we varied which medium they saw first. People who saw a description first reported more false images and memories than did people who saw a photo first, a result that fits with an anchoring account of false childhood memories.

Familiarity breeds distortion: the effects of media exposure on false reports concerning media coverage of the terrorist attacks in london on 7 July 2005

The present experiment investigated whether increased media exposure could lead to an increase in memory distortions regarding a traumatic public event: the explosion of the No. 30 bus in Tavistock Square, London on 7 July 2005. A total of 150 Swedish and 150 UK participants completed a series of questionnaires about their memory of either (i) the aftermath of the explosion, (ii) a non-existent computerised reconstruction of the moment of the explosion, or (iii) non-existent closed circuit television footage of the moment of the explosion. In line with the availability heuristic, U.K. participants were more likely than Swedish participants to claim to have seen all three types of footage. Furthermore, a subsample of U.K. participants who appeared to have developed false "memories" of seeing the No. 30 bus explode scored significantly higher on measures of dissociation and fantasy proneness than participants who did not develop false "memories". This experiment provides further support for the role of imaginative processes in the development of false 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.