Strategies for verifying false autobiographical memories

This study examined the types of strategies people use to verify putative childhood memories and the degree to which their preferred strategies are restricted in typical memory implantation studies. We asked subjects to describe a situation in which they recalled a false childhood experience and a hypothetical situation in which they pretended to have developed a false memory after taking part in a memory implantation study. We also asked them how they did (or would) determine the source of the event. We found that subjects relied primarily on other people and cognitive strategies to verify their experiences. These results suggest that laboratory situations cultivate false memories in part because they prevent people from talking to others about the false event, which causes them to rely on less optimal strategies.     

Creating false memories for events that occurred before versus after the offset of childhood amnesia

We examined whether false images and memories for childhood events are more likely when the event supposedly took place during the period of childhood amnesia. Over three interviews, participants recalled six events: five true and one false. Some participants were told that the false event happened when they were 2 years old (Age 2 group), while others were told that it happened when they were 10 years old (Age 10 group). We compared participants’ reports of the false event to their reports of a true event from the same age. Consistent with prior research on childhood amnesia, participants in the Age 10 group were more likely than participants in the Age 2 group to remember their true event and they reported more information about it. Participants in the Age 2 group, on the other hand, were more likely to develop false images and memories than participants in the Age 10 group. Furthermore, once a false image or memory developed, there were no age-related differences in the amount of information participants reported about the false event. We conclude that childhood amnesia increases our susceptibility to false suggestion, thus our results have implications for court cases where early memories are at issue.     

Emotional content of true and false memories

Many people believe that emotional memories (including those that arise in therapy) are particularly likely to represent true events because of their emotional content. But is emotional content a reliable indicator of memory accuracy? The current research assessed the emotional content of participants’ pre-existing (true) and manipulated (false) memories for childhood events. False memories for one of three emotional childhood events were planted using a suggestive manipulation and then compared, along several subjective dimensions, with other participants’ true memories. On most emotional dimensions (e.g., how emotional was this event for you?), true and false memories were indistinguishable. On a few measures (e.g., intensity of feelings at the time of the event), true memories were more emotional than false memories in the aggregate, yet true and false memories were equally likely to be rated as uniformly emotional. These results suggest that even substantial emotional content may not reliably indicate memory accuracy.     

Comparison of neural activity that leads to true memories,false memories,and forgetting: An fMRI study of the misinformation effect

False memories can occur when people are exposed to misinformation about a past event. Of interest here are the neural mechanisms of this type of memory failure. In the present study, participants viewed photographic vignettes of common activities during an original event phase (OEP), while we monitored their brain activity using fMRI. Later, in a misinformation phase, participants viewed sentences describing the studied photographs, some of which contained information conflicting with that depicted in the photographs. One day later, participants returned for a surprise item memory recognition test for the content of the photographs. Results showed reliable creation of false memories, in that participants reported information that had been presented in the verbal misinformation but not in the photographs. Several regions were more active during the OEP for later accurate memory than for forgetting, but they were also more active for later false memories, indicating that false memories in this paradigm are not simply caused by failure to encode the original event. There was greater activation in the ventral visual stream for subsequent true memories than for subsequent false memories, however, suggesting that differences in encoding may contribute to later susceptibility to misinformation.     

Creating false memories for events that occurred before versus after the offset of childhood amnesia

We examined whether false images and memories for childhood events are more likely when the event supposedly took place during the period of childhood amnesia. Over three interviews, participants recalled six events: five true and one false. Some participants were told that the false event happened when they were 2 years old (Age 2 group), while others were told that it happened when they were 10 years old (Age 10 group). We compared participants' reports of the false event to their reports of a true event from the same age. Consistent with prior research on childhood amnesia, participants in the Age 10 group were more likely than participants in the Age 2 group to remember their true event and they reported more information about it. Participants in the Age 2 group, on the other hand, were more likely to develop false images and memories than participants in the Age 10 group. Furthermore, once a false image or memory developed, there were no age-related differences in the amount of information participants reported about the false event. We conclude that childhood amnesia increases our susceptibility to false suggestion, thus our results have implications for court cases where early memories are at issue.     

Recollection rejection: how children edit their false memories.

A new methodology is presented for studying children's ability to suppress memory reports of false-but-gist-consistent events, one that measures children's use of a specific editing operation (recollection rejection) that suppresses false reports by accessing verbatim traces of true events. Children make memory reports under 2 instructional conditions, verbatim and gist, and the data are analyzed with fuzzy-trace theory's conjoint-recognition model. Application of the new methodology in studies of children's false memory for narrative events revealed that (a) false-memory editing increases dramatically between early and middle childhood, (b) even young children spontaneously edit their false memories, (c) measures of children's false-memory editing react appropriately to experimental manipulations, and (d) developmental reductions in the incidence of false-memory reports are primarily due to developmental improvements in verbatim memory ability (rather than to decreases in the formation of false memories). Implications for child forensic interviewing are discussed.     

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.     

Emotional content of true and false memories

Many people believe that emotional memories (including those that arise in therapy) are particularly likely to represent true events because of their emotional content. But is emotional content a reliable indicator of memory accuracy? The current research assessed the emotional content of participants' pre-existing (true) and manipulated (false) memories for childhood events. False memories for one of three emotional childhood events were planted using a suggestive manipulation and then compared, along several subjective dimensions, with other participants' true memories. On most emotional dimensions (e.g., how emotional was this event for you?), true and false memories were indistinguishable. On a few measures (e.g., intensity of feelings at the time of the event), true memories were more emotional than false memories in the aggregate, yet true and false memories were equally likely to be rated as uniformly emotional. These results suggest that even substantial emotional content may not reliably indicate memory accuracy.     

Mood,dissociation and false memories using the Deese‐Roediger‐McDermott procedure

Who is likely to have a false memory? Does being in a certain transient state, such as a negative mood, mean that a person is more like to have a false memory? These important questions are examined using the Deese‐Roediger‐McDermott (DRM) procedure. The amount of false memories was compared with people's score on a dissociation measure and by mood. Unlike past research, which has used different procedures to explore false memories, we found that dissociation was not associated with false memories. We argue that this is because the DRM procedure requires two processes for a false memory (the generation of the critical lure and mistaking its source), while most false memory procedures only require one process (source monitoring error) because the errant information is suggested to the participant. This pattern of results suggests that only errors with the source monitoring process are associated with dissociation. We found that mood was related to false memories, but it was dependent on the specific task demands. If participants were told to recall as many words as they could, then people in a negative mood had more false memories. However, if they were told to recall as many words as they felt like recalling, then there were more false memories for people in a positive mood. This can be explained by the mood‐as‐input hypothesis. Results are discussed in relation to both theories and applications of memory.     

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.     

True photographs and false memories

Abstract— Some trauma-memory-oriented psychotherapists advise clients to review old family photo albums to cue suspected "repressed" memories of childhood sexual abuse. Old photos might cue long-forgotten memories, but when combined with other suggestive influences they might also contribute to false memories. We asked 45 undergraduates to work at remembering three school-related childhood events (two true events provided by parents and one pseudoevent). By random assignment, 23 subjects were also given their school classes' group photos from the years of the to-be-recalled events as memory cues. As predicted, the rate of false-memory reports was dramatically higher in the photo condition than in the no-photo condition. Indeed, the rate of false-memory reports in the photo condition was substantially higher than the rate in any previously published study.     

Children's kinematic false memories

ABSTRACT

Individuals misrecognise as seen the never-presented natural continuation of an action. These false memories derive from the running of kinematic mental models of the actions seen, which rest on motor inferences from implicit knowledge. We verified an implied prediction: kinematic false memories should be detectable even in children. The participants in our experiments first observed photos in which actors were about to perform actions on objects. At recognition they were presented with the original photos, plus (a) distractors representing the unseen natural continuation of the original actions, (b) distractors representing the beginning of other actions on the same objects and (c) distractors representing completed different actions on the same objects. In contrast to the original studies in which participants expressed their confidence in recognition, in our experiments the participants catgorirzed the action as seen or not seen. After replicating the original results with the dichotomous recognition task (Experiment 1), we detected spontaneous false memories also in children (Experiment 2).     

Self-relevance enhances susceptibility to false memory

Eyewitness testimony serves as important evidence in the legal system. Eyewitnesses of a crime can be either the victims themselves—for whom the experience is highly self-referential—or can be bystanders who witness and thus encode the crime in relation to others. There is a gap in past research investigating whether processing information in relation to oneself versus others would later impact people's suggestibility to misleading information. In two experiments (Ns = 68 and 122) with Dutch and Chinese samples, we assessed whether self-reference of a crime event (i.e., victim vs. bystander) affected their susceptibility to false memory creation. Using a misinformation procedure, we photoshopped half of the participants' photographs into a crime slideshow so that they saw themselves as victims of a nonviolent crime, while others watched the slideshow as mock bystander witnesses. In both experiments, participants displayed a self-enhanced suggestibility effect: Participants who viewed themselves as victims created more false memories after receiving misinformation than those who witnessed the same crime as bystanders. These findings suggest that self-reference might constitute a hitherto new risk factor in the formation of false memories when evaluating eyewitness memory reports.     

Individual differences in working memory capacity affect false memories for missing aspects of events

Recently, Gerrie, Belcher, and Garry (2006) found that, when participants watch an event with parts missing, they falsely claim to have seen the missing parts—but they were more likely to claim they had seen less crucial parts than more crucial parts. Their results fit with a source-monitoring framework (SMF; Johnson, Hashtroudi, & Lindsay, 1993) explanation of false memories. In this paper we used individual differences in working memory capacity (WMC) to examine the SMF explanation of false memories for missing aspects of events. An accumulating body of research suggests that WMC is strongly related to controlling attention, including the ability to distinguish between sources of information. The primary purpose of the present study was to examine whether people with larger WMC are better able to ward off false memories for missing information than those with a smaller WMC. We showed that higher WMC reduced false recognition of crucial information, but did not change false recognition of noncrucial information. Additionally, we found that WMC had little effect on participants’ subjective experience of true and false recognition of events, regardless whether the information was crucial or not. These results provide further evidence that people's WMC is related to their source-monitoring ability.     

Compelling untruths: content borrowing and vivid false memories

False memories are sometimes accompanied by surprisingly vivid experiential detail that makes them difficult to distinguish from actual memories. Such strikingly real false memories may be produced by a process called content borrowing in which details from presented items are errantly borrowed to corroborate the occurrence of the false memory item. In 2 experiments using think-out-loud protocols at both study and test, evidence for content borrowing occurred for more than half of the false remember judgments participants reported. The present study also provides evidence consistent with recollection rejection and distinctiveness playing a role in false-memory editing.     

Photographs cause false memories for the news

What is the effect on memory when seemingly innocuous photos accompany false reports of the news? We asked people to read news headlines of world events, some of which were false. Half the headlines appeared with photographs that were tangentially related to the event; others were presented without photographs. People saw each headline only once, and indicated whether they remembered the event, knew about it, or neither. Photos led people to immediately and confidently remember false news events. Drawing on the Source Monitoring Framework (Johnson, Hashtroudi, & Lindsay, 1993), we suggest that people often relied on familiarity and other heuristic processes when making their judgments and thus experienced effects of the photos as evidence of memory for the headlines.     

Importing perceived features into false memories

False memories sometimes contain specific details, such as location or colour, about events that never occurred. Based on the source-monitoring framework, we investigated one process by which false memories acquire details: the reactivation and misattribution of feature information from memories of similar perceived events. In Experiments 1A and 1B, when imagined objects were falsely remembered as seen, participants often reported that the objects had appeared in locations where visually or conceptually similar objects, respectively, had actually appeared. Experiment 2 indicated that colour and shape features of seen objects were misattributed to false memories of imagined objects. Experiment 3 showed that perceived details were misattributed to false memories of objects that had not been explicitly imagined. False memories that imported perceived features, compared to those that presumably did not, were subjectively more like memories for perceived events. Thus, perception may be even more pernicious than imagination in contributing to false memories.     

Importing perceived features into false memories

False memories sometimes contain specific details, such as location or colour, about events that never occurred. Based on the source-monitoring framework, we investigated one process by which false memories acquire details: the reactivation and misattribution of feature information from memories of similar perceived events. In Experiments 1A and 1B, when imagined objects were falsely remembered as seen, participants often reported that the objects had appeared in locations where visually or conceptually similar objects, respectively, had actually appeared. Experiment 2 indicated that colour and shape features of seen objects were misattributed to false memories of imagined objects. Experiment 3 showed that perceived details were misattributed to false memories of objects that had not been explicitly imagined. False memories that imported perceived features, compared to those that presumably did not, were subjectively more like memories for perceived events. Thus, perception may be even more pernicious than imagination in contributing to false memories.     

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.