The co-witness misinformation effect: Memory blends or memory compliance?

For 30 years hundreds of researchers have shown participants videos and slide-sequences of events, presented the participants with misleading information, and found that this misinformation distorted their memories. The purpose of this study was to establish whether those misled participants are reporting a memory blend of the two sources of information or whether they are simply complying with the post-event information. A total of 92 participants were shown one of two versions of six different videos, which included some subtle differences. After having watched each video individually, participants were paired with someone who had seen the other version and they discussed the clips together. They then individually answered questions about the videos, and their responses showed that some of the distorted memories were blends of the original information and the post-event information. The implications of these findings are discussed.     

Emotions and false memories: valence or arousal?

The effects of mood on false memories have not been studied systematically until recently. Some results seem to indicate that negative mood may reduce false recall and thus suggest an influence of emotional valence on false memory. The present research tested the effects of both valence and arousal on recall and recognition and indicates that the effect is actually due to arousal. In fact, whether participants' mood is positive, negative, or neutral, false memories are significantly more frequent under conditions of high arousal than under conditions of low arousal.     

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.     

Memory loss versus memory distortion: The role of encoding and retrieval deficits in Korsakoff patients’ false memories

Recent studies with the Deese/Roediger-McDermott (DRM) paradigm have revealed that Korsakoff patients show reduced levels of false recognition and different patterns of false recall compared to controls. The present experiment examined whether this could be attributed to an encoding deficit, or rather to problems with explicitly retrieving thematic information at test. In a variation on the DRM paradigm, both patients and controls were presented with associative as well as categorised word lists, with the order of recall and recognition tests manipulated between-subjects. The results point to an important role for the automatic/controlled retrieval distinction: Korsakoff patients’ false memory was only diminished compared to controls’ when automatic or short-term memory processes could not be used to fulfil the task at hand. Hence, the patients’ explicit retrieval deficit appears to be crucial in explaining past and present data. Results are discussed in terms of fuzzy-trace and activation-monitoring theories.     

Can false memories spontaneously recover?

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

Can false memories spontaneously recover?

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

Memory Development or the Development of Memory?

For 30 years, the question "What is memory development the development of?" has guided research on children's memory. As theories and research paradigms have evolved over this period, so too has knowledge of the surprising mnemonic competence of young children and of age-related differences in memory performance. Never the less, there are serious limits to current understanding of the development of memory. Indeed, there have been few investigations of changes over time in the memory skills of individual children, and researchers have yet to shed much light on the more difficult question of "What are the forces that propel the development of skilled remembering?" From our perspective, the answer to this question will require movement toward longitudinal research designs that illuminate the mechanisms that bring about developmental change.     

Does collaborative remembering reduce false memories?

Collaborative remembering refers to recall by groups rather than by an individual. Three experiments investigated whether, relative to individual remembering, collaborative remembering decreased correct recall and false recall using the Deese‐Roediger‐McDermott paradigm. Participants were first asked to study and recall five lists of 15 words that were each semantically associated with a critical non‐presented word. Half the participants recalled the words by themselves, while the remaining half were assigned to pairs and collaboratively recalled the words. In Experiment 1, pairs produced the same number of false or correct words as individuals who were tested alone. In Experiment 2, the interpersonal closeness of the groups was also manipulated: friends and pairs who were not friends were assigned to the collaborative groups. Both friends and non‐friends produced fewer false or correct words than individuals. Experiment 3, in which the performance of the individuals and non‐friend pairs were compared using a recall test of the same 75 words as the previous experiments, replicated the results of Experiment 2. These results are discussed in terms of the retrieval‐strategy disruption.     

Can false memories prime problem solutions?

Previous research has suggested that false memories can prime performance on related implicit and explicit memory tasks. The present research examined whether false memories can also be used to prime higher order cognitive processes, namely, insight-based problem solving. Participants were asked to solve a number of compound remote associate task (CRAT) problems, half of which had been primed by the presentation of Deese/Roediger–McDermott (DRM) lists whose critical lure was also the solution to the problem. The results showed that when the critical lure: (a) was falsely recalled, CRAT problems were solved more often and significantly faster than problems that were not primed by a DRM list and (b) was not falsely recalled, CRAT problem solution rates and times were no different than when there was no DRM priming. A second experiment demonstrated that these outcomes were not a simple artifact of the inclusion of a recall test prior to the problem solving task. The implications of these results are discussed with regard to the previous literature on priming and the adaptive function of false memories.     

Are false memories more difficult to forget than accurate memories? The effect of retention interval on recall and recognition

What is the effect of retention interval on accurate and false recollection in the Deese, Roediger, and McDermott (DRM) procedure? Previous research has suggested that false recall is more persistent than accurate recall, but the recognition results have been inconsistent. In two parametric studies, we tested recall and recognition for the same DRM lists, over retention intervals that ranged from no delay to a 2-month delay. We found that accurate and false memory were diminished by increases in retention interval, false memory persistence was present for recall and recognition, greater persistence for false memory than for accurate memory was more readily observed for recall than recognition, and the highthreshold (Pr), signal detection (d’), and nonparametric (A’) recognition measures differed in their sensitivity for detecting change. The effect of retention interval on accurate and false memory is consistent with expectations from fuzzy trace theory. In the DRM procedure, truth is not more memorable than fiction.     

The co-witness misinformation effect: memory blends or memory compliance?

For 30 years hundreds of researchers have shown participants videos and slide-sequences of events, presented the participants with misleading information, and found that this misinformation distorted their memories. The purpose of this study was to establish whether those misled participants are reporting a memory blend of the two sources of information or whether they are simply complying with the post-event information. A total of 92 participants were shown one of two versions of six different videos, which included some subtle differences. After having watched each video individually, participants were paired with someone who had seen the other version and they discussed the clips together. They then individually answered questions about the videos, and their responses showed that some of the distorted memories were blends of the original information and the post-event information. The implications of these findings are discussed.     

Memories of uncertain origin: Dreamt or real?

The existence of a memory whose origin, real or dreamt, was uncertain was reported by just over half of an undergraduate sample of 358. Each respondent described one such memory if they had one. The memories were typically of mundane events, although 10 respondents described possible crimes. Respondents were often concerned to resolve the origin of these memories. Their plausibility, vividness, and how well the events fitted into one's life were often considered by the respondents, but where resolution occurred it was frequently based on evidence obtained from the physical or social environment. The reported qualities of the event did not correlate with whether the respondent thought it more likely to have been originally a dream or a real event.     

Memories of uncertain origin: dreamt or real?

The existence of a memory whose origin, real or dreamt, was uncertain was reported by just over half of an undergraduate sample of 358. Each respondent described one such memory if they had one. The memories were typically of mundane events, although 10 respondents described possible crimes. Respondents were often concerned to resolve the origin of these memories. Their plausibility, vividness, and how well the events fitted into one's life were often considered by the respondents, but where resolution occurred it was frequently based on evidence obtained from the physical or social environment. The reported qualities of the event did not correlate with whether the respondent thought it more likely to have been originally a dream or a real event.     

How does negative emotion cause false memories?

Remembering negative events can stimulate high levels of false memory, relative to remembering neutral events. In experiments in which the emotional valence of encoded materials was manipulated with their arousal levels controlled, valence produced a continuum of memory falsification. Falsification was highest for negative materials, intermediate for neutral materials, and lowest for positive materials. Conjoint-recognition analysis produced a simple process-level explanation: As one progresses from positive to neutral to negative valence, false memory increases because (a) the perceived meaning resemblance between false and true items increases and (b) subjects are less able to use verbatim memories of true items to suppress errors.     

Secrecy and suggestibility: are children's memories for secrets less suggestible than other memories?

Adult secrecy research has found a memory‐enhancing effect for information kept secret as the secret is mentally rehearsed each time the adult is required to prevent it being reported (e.g. Lane & Wegner, 1994). The present study examined possible memory‐enhancing effects of children keeping information secret. Two hundred and thirty two five to eight year olds took part in a puppet‐making task. During the task the puppet‐maker sprayed glitter onto the puppets. Half the children were told to keep a secret (that the spray had been taken from Disneyland) and the other half (the control group) were merely told the spray was from Disneyland. One week later the children were interviewed either by the puppet‐maker (the secret‐giver) or by the puppet‐maker's friend (the secret‐novice). The five to six year olds showed no effect of the secret condition, whereas the seven to eight year olds made significantly less errors in their free recall in the secret condition compared to the control condition. There was no effect of the secret condition on children's suggestibility to leading questions. However, both age groups were significantly more suggestible when interviewed by the secret‐giver. Finally, both age groups showed a recall deficit in the secret condition. Copyright © 2004 John Wiley & Sons, Ltd.     

When false memories do not occur: Not thinking of the lure or remembering that it was not heard?

The aim of the present study was to evaluate two explanations for the non-occurrence of false memories in the Deese-Roediger-McDermott (DRM) paradigm. One explanation was that a critical lure is not recalled because the list failed to evoke it in the participant's mind. Another possible explanation was that the participant would identify the critical lure and would remember, at the time of recall, that the lure was not produced by an external source. In order to explore these two possible explanations for the non-occurrence of false memories, an experimental phase was added to the usual DRM paradigm: participants were asked to recall items they thought of but did not recall because these items were not members of the list presented by the experimenter. Among participants who did not recall the critical lure during the standard recall task, those who recalled the critical lure during the additional phase outnumbered those who did not recall it. This result is more consistent with the second explanation than with the first one.     

When false memories do not occur: not thinking of the lure or remembering that it was not heard?

The aim of the present study was to evaluate two explanations for the non-occurrence of false memories in the Deese-Roediger-McDermott (DRM) paradigm. One explanation was that a critical lure is not recalled because the list failed to evoke it in the participant's mind. Another possible explanation was that the participant would identify the critical lure and would remember, at the time of recall, that the lure was not produced by an external source. In order to explore these two possible explanations for the non-occurrence of false memories, an experimental phase was added to the usual DRM paradigm: participants were asked to recall items they thought of but did not recall because these items were not members of the list presented by the experimenter. Among participants who did not recall the critical lure during the standard recall task, those who recalled the critical lure during the additional phase outnumbered those who did not recall it. This result is more consistent with the second explanation than with the first one.     

Underestimation of prior remembering and susceptibility to false memories: two sides of the same coin?

In two studies, we explored whether susceptibility to false memories and the underestimation of prior memories (i.e., forgot-it-all-along effect) tap overlapping memory phenomena. Study 1 investigated this issue by administering the Deese/Roediger–McDermott task (DRM) and the forgot-it-all-along (FIA) task to an undergraduate sample (N = 110). It was furthermore explored how performances on these tasks correlate with clinically relevant traits such as fantasy proneness, dissociative experiences, and cognitive efficiency. Results show that FIA and DRM performances are relatively independent from each other, suggesting that these measures empirically apparently refer to separate dimensions. However, they do not seem to define different profiles in terms of dissociation, fantasy proneness, and cognitive efficiency. Study 2 replicated the finding of relative independence between false memory propensity (as measured with the DRM task) and the underestimation of prior memories (as measured with an autobiographical memory dating task) in people with a history of childhood sexual abuse (N = 35).     

Are nonconscious processes sufficient to produce false memories?

Seamon, Luo, and Gallo (1998) reported evidence that nonconscious processes could produce false recognition in a converging-associates task, whereby subjects falsely remember a nonstudied lure (e.g., sleep) after studying a list of related words (bed, rest, awake...). Zeelenberg, Plomp, and Raaijmakers (2003) failed to observe this false recognition effect when list word recognition was at chance. We critically evaluate the evidence for nonsconscious processing and report the results of a new experiment designed to overcome previous methodological limitations. Consistent with Seamon et al., we found that conscious activation of a related lure during study was not necessary for its subsequent recognition; consistent with Zeelenberg et al., we found no evidence for recognition of related lures under conditions where there was no memory for studied words. It is currently unknown whether conscious recollection of the studied items is necessary for false recognition or if nonconscious activation of the lure is sufficient.