Evidence that nonconscious processes are sufficient to produce false memories

Are nonconscious processes sufficient to cause false memories of a nonstudied event? To investigate this issue, we controlled and measured conscious processing in the DRM task, in which studying associates (e.g., bed, rest, awake...) causes false memories of nonstudied associates (e.g., sleep). During the study phase, subjects studied visually masked associates at extremely rapid rates, followed by immediate recall. After this initial phase, nonstudied test words were rapidly presented for perceptual identification, followed by recognition memory judgments. On the perceptual identification task, we found significant priming of nonstudied associates, relative to control words. We also found significant false recognition of these nonstudied associates, even when subjects did not recall this word at study or identify it at test, indicating that nonconscious processes can cause false recognition. These recognition effects were found immediately after studying each list of associates, but not on a delayed test that occurred after the presentation of several intervening lists. Nonconscious processes are sufficient to cause this memory illusion on immediate tests, but may be insufficient for more vivid and lasting false memories.     

Theoretical and forensic implications of developmental studies of the DRM illusion

In the study of false memory, developmental research on the Deese–Roediger–McDermott (DRM) illusion has played a pivotal role in theory evaluation and forensic application. The extensive developmental DRM literature (55 experiments published in English-language journals) provided the first clear evidence that false memories can increase dramatically from early childhood onward, whereas traditional ideas about cognitive development predict steady declines. Similar increases have recently been reported in false memory for complex, realistic life events, using forensically oriented paradigms. Age improvements in the ability to connect meaning across words have been found to be necessary and sufficient for developmental increases in the DRM illusion. When the data of developmental DRM studies are combined with parallel findings from forensically oriented paradigms, the result is an existence proof that a principle used by the law to evaluate children’s evidence is mistaken. According to that principle, children’s versions of events are always more likely to be infected with false memories than those of adults, and hence, juries should give more weight to adults’ versions of events.     

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).     

The role of rehearsal and generation in false memory creation

The current research investigated one possible mechanism underlying false memories in the Deese-Roediger-McDermott (DRM) paradigm. In the DRM paradigm, participants who study lists of related words (e.g., "table, sitting, bench ...") frequently report detailed memories for the centrally related but non-presented critical lure (e.g., "chair"). One possibility is that participants covertly call to mind the critical non-presented lure during the study phase, and later misattribute memory for this internally generated event to its external presentation. To investigate this, the DRM paradigm was modified to allow collection of on-line thoughts during the study phase. False recognition increased following generation during study. False recognition also increased following study of longer lists; this effect was partially explained by the fact that longer lists were more likely to elicit generations of the critical lure during study. Generation of the lure during study contributes to later false recognition, although it does not explain the entire effect.     

The role of rehearsal and generation in false memory creation

The current research investigated one possible mechanism underlying false memories in the Deese-Roediger-McDermott (DRM) paradigm. In the DRM paradigm, participants who study lists of related words (e.g., “table, sitting, bench …”) frequently report detailed memories for the centrally related but non-presented critical lure (e.g., “chair”). One possibility is that participants covertly call to mind the critical non-presented lure during the study phase, and later misattribute memory for this internally generated event to its external presentation. To investigate this, the DRM paradigm was modified to allow collection of on-line thoughts during the study phase. False recognition increased following generation during study. False recognition also increased following study of longer lists; this effect was partially explained by the fact that longer lists were more likely to elicit generations of the critical lure during study. Generation of the lure during study contributes to later false recognition, although it does not explain the entire effect.     

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.     

Music evokes vivid autobiographical memories

Music is strongly intertwined with memories—for example, hearing a song from the past can transport you back in time, triggering the sights, sounds, and feelings of a specific event. This association between music and vivid autobiographical memory is intuitively apparent, but the idea that music is intimately tied with memories, seemingly more so than other potent memory cues (e.g., familiar faces), has not been empirically tested. Here, we compared memories evoked by music to those evoked by famous faces, predicting that music-evoked autobiographical memories (MEAMs) would be more vivid. Participants listened to 30 songs, viewed 30 faces, and reported on memories that were evoked. Memories were transcribed and coded for vividness as in Levine, B., Svoboda, E., Hay, J. F., Winocur, G., & Moscovitch, M. [2002. Aging and autobiographical memory: Dissociating episodic from semantic retrieval. Psychology and Aging, 17, 677–689]. In support of our hypothesis, MEAMs were more vivid than autobiographical memories evoked by faces. MEAMs contained a greater proportion of internal details and a greater number of perceptual details, while face-evoked memories contained a greater number of external details. Additionally, we identified sex differences in memory vividness: for both stimulus categories, women retrieved more vivid memories than men. The results show that music not only effectively evokes autobiographical memories, but that these memories are more vivid than those evoked by famous faces.     

The importance of material-processing interactions in inducing false memories

Deep encoding, relative to shallow encoding, has been shown to increase the probability of false memories in the Deese/Roediger-McDermott (DRM) paradigm (Thapar & McDermott, 2001; Toglia, Neuschatz, & Goodwin, 1999). In two experiments, we showed important limitations on the generalizability of this phenomenon; these limitations are clearly predicted by existing theories regarding the mechanisms underlying such false memories (e.g., Roediger, Watson, McDermott, & Gallo, 2001). Specifically, asking subjects to attend to phonological relations among lists of phonologically associated words (e.g., weep, steep, etc.) increased the likelihood of false recall (Experiment 1) and false recognition (Experiment 2) of a related, nonpresented associate (e.g., sleep), relative to a condition in which subjects attended to meaningful relations among the words. These findings occurred along with a replication of prior findings (i.e., a semantic encoding task, relative to a phonological encoding task, enhanced the likelihood of false memory arising from a list of semantically associated words), and they place important constraints on theoretical explanations of false memory.     

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.     

A content analysis of involuntary autobiographical memories: examining the positivity effect in old age

Although research on autobiographical memory is growing steadily, very little is known about involuntary autobiographical memories that are spontaneously recalled in everyday life. In addition, very few studies have examined the actual content of autobiographical memories and how the content might change as a function of age. The present study carried out a content analysis of involuntary autobiographical memories recorded by young (N = 11) and old (N = 10) volunteers over a period of 1 week. A total of 224 memories were classified into 17 categories according to the type of content recalled (e.g., births, holidays, school). The results support the socioemotional theory of ageing (Carstensen, Isaacowitz & Charles, 1999) by showing that although young and old adults recalled a similar number of memories with a typically positive content (e.g., holidays, special occasions), older adults recalled very few memories with a typically negative content (e.g., accidents, stressful events). Moreover, even when such negative memories were recalled, they were rated by older adults as neutral or even positive. This so-called positivity effect in old age could not be entirely explained by participants' ratings of mood at the time of recall. Theoretical and practical implications of these findings for ageing and autobiographical memory research are discussed.     

Reinstatement of odour context cues veridical memories but not false memories

ABSTRACT

The sense of smell has made a recent return to the forefront of research on episodic memory. Odour context cues can reactivate recently encoded memories during sleep-dependent memory consolidation [e.g., Rasch, B., Buchel, C., Gais, S., & Born, J. (2007). Odor cues during slow-wave sleep prompt declarative memory consolidation. Science, 315, 1426–1429], and reinstating the odour experienced during encoding at test results in superior recall and recognition [e.g., Isarida, T., Sakai, T., Kubota, T., Koga, M., Katayama, Y., & Isarida, T. K. (2014). Odor-context effects in free recall after a short retention interval: A new methodology for controlling adaptation. Memory & Cognition, 42, 421–433]. However, whether the impact of odour cues is restricted to the specific memories studied in the presence of the odour, or whether reinstating the odour also cues unstudied memories that are semantically related to the studied memories (i.e., false memories) is unknown. We used the Deese-Roediger-McDermott false memory paradigm to quantify the impact of odour cues on both veridical memory and false memory. Reinstating the odour presented during the study of the DRM word lists at the test phase resulted in better free recall of the studied words, but had no statistically significant impact on the number of false memories produced. We argue that odour cues influence recall of the memories they co-occurred with during study but potentially not semantically related memories.     

Generative processing and false memories: when there is no cost

Encoding manipulations (e.g., levels of processing) that facilitate retention often result in greater numbers of false memories, a pattern referred to as the more is less effect (M. P. Toglia, J. S. Neuschatz, & K. A. Goodwin, 1999). The present experiments explored false memories under generative processing. In Experiments 1-3, using Deese-Roediger-McDermott (DRM) lists with items that were either read or generated, the authors found recognition and recall tests indicated generation effects for true memories but no increases in false memories (i.e., generation at no cost). In Experiment 4, in a departure from the DRM methodology, a cuing procedure resulted in a more is less pattern for congruous generation,and a no cost pattern for incongruous generation. This highlights the critical distinction between these encoding contexts.     

Using story contexts to bias children’s true and false memories

The effects of embedding standard Deese/Roediger-McDermott (DRM) lists into stories whose context biased interpretation either toward or away from the overall themes of the DRM lists on both true and false recognition were investigated with 7- and 11-year-olds. These biased story contexts were compared with the same children’s susceptibility to false memory illusions using the standard DRM list presentation paradigm. The results showed the usual age effects for true and false memories in the standard DRM list paradigm, where 11-year-olds exhibited higher rates of both true and false recognition compared with the 7-year-olds. Importantly, when DRM lists were embedded in stories, these age effects disappeared for true recognition. For false recognition, although developmental differences were attenuated, older children were still more susceptible to false memory illusions than younger children. These findings are discussed in terms of current theories of children’s false memories as well as the role of themes and elaboration in children’s memory development.     

The Content of Older Adults’ Autobiographical Memories Predicts the Beneficial Outcomes of Reminiscence Group Participation

Much research has investigated the beneficial outcomes of reminiscence groups, like guided autobiography groups. Few have assessed whether the content of the autobiographical memories shared during these groups, however, predicts beneficial outcomes. This is the main goal of the current study. Sixteen participants responded to questionnaires about depression, death attitudes, and psychological well-being before and after an 8-week reminiscence group. Results indicated that group participation decreased depression, lowered fear and avoidance of death, and improved death acceptance. The 41 memory narratives collected from group participants were content analyzed for affective, cognitive, and sensory processes. Analyses revealed that memory content predicted levels of depression after group participation. Specifically, memories with more positive affective words (e.g., happy) predicted less depressive symptoms, and memories with negative cognitive process words (e.g., perhaps) predicted more depressive symptoms. The implications for remembering life events in old age are discussed.     

Palestinian Autobiographical Memory Regarding the 1948 Palestinian Exodus

Background : Collective memory of intractable conflict is an important sociopsychological phenomenon which influences the psychological and behavioral reactions of each party to the conflict. This memory is composed of two kinds of memories: autobiographical memory—the memory of the people who experienced the given events directly—and indirect‐collective memory—the memory of the people who learned about the given events second hand, via books, etc. Purpose : This study explores the characteristics of Palestinian autobiographical memory with respect to the causes of the 1948 Palestinian exodus and how it relates to other Palestinian memories of that exodus (official, historical/academic, and indirect‐collective). From these empirical findings, theoretical insights are concluded. Method : This is done by analyzing the content of four oral history projects of 1948 Palestinians refugees (in total, 131 interviewees from 38 localities). In addition, the content of these projects is compared to the accounts of documented Israeli history (using the research of Israeli historian Benny Morris). Studies of the other Palestinian memories are also used. Findings : The findings reveal that the Palestinian autobiographical memory is not a typical memory of conflict (e.g., with relatively low focus on the expulsion cause for the exodus). It is also compatible to a large degree with documented Israeli history. However, it is very different from other Palestinian memories of the exodus (official, historical/academic, and indirect‐collective), which focus almost exclusively on the expulsion cause. Other empirical findings and their explanations are discussed. The findings have mostly theoretical implications regarding various kinds of memories of conflicts (and memories in general), as well as some methodological implications with regard to the usage of oral history.     

Age differences in the rejection of false memories: The effects of giving warning instructions and slowing the presentation rate

Two experiments were conducted to examine whether children of different ages differ in their ability to reject associative false memories with the Deese–Roediger–McDermott (DRM) paradigm. Two different types of manipulations that are thought to facilitate false memory rejection in adults—slowing the presentation rate and issuing explicit warnings—were analyzed in younger and older children. The results showed that older children were more able than younger children to reject associative false memories through warnings and by slowing the presentation rate. We conclude that although older children are, in general, more prone to produce false memories with the DRM paradigm, they are also more able to reject them when certain conditions facilitate the editing process.     

Autobiographical elaboration reduces memory distortion: cognitive operations and the distinctiveness heuristic

Retrieval monitoring enhances episodic memory accuracy. For instance, false recognition is reduced when participants base their decisions on more distinctive recollections, a retrieval monitoring process called the distinctiveness heuristic. The experiments reported here tested the hypothesis that autobiographical elaboration during study (i.e., generating autobiographical memories in response to cue words) would lead to more distinctive recollections than other item-specific encoding tasks, enhancing retrieval monitoring accuracy at test. Consistent with this hypothesis, false recognition was less likely when participants had to search their memory for previous autobiographical elaborations, compared to previous semantic judgments. These false recognition effects were dissociated from true recognition effects across four experiments, implicating a recollection-based monitoring process that was independent from familiarity-based processes. Separately obtained subjective measures provided converging evidence for this conclusion. The cognitive operations engaged during autobiographical elaboration can lead to distinctive recollections, making them less prone to memory distortion than other types of deep or semantic encoding.     

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.     

Retrieval‐induced forgetting of autobiographical memory details

Several studies suggest that intrusive and overgeneral autobiographical memory are correlated. Thus, paradoxically, in some patients a hyperaccessibility of memory for one (series of) event(s) goes hand‐in‐hand with a scarcity of memories for other personal experiences. This clinical observation is reminiscent of the laboratory phenomenon of retrieval‐induced forgetting (RIF). This refers to the finding that repeatedly recalling some experimental stimuli impairs subsequent recall of related (i.e., tied to the same retrieval cue) stimuli. RIF of emotional autobiographical memories might provide an experimental model for the clinical memory phenomena in question. The present paper reports two experiments that explored the merits of applying the retrieval practice paradigm to relatively broad categories of autobiographical memories. Both studies found a significant RIF effect in that practised memories were recalled better than unrelated unpractised (baseline) memories. In addition, unpractised memories that were related to the practised memories were recalled more poorly than baseline memories. Implications of these findings for modelling the co‐occurrence of intrusive and overgeneral memories are discussed.