Dissociated developmental trajectories for semantic and phonological false memories

False recognition following presentation of semantically related and phonologically related word lists was evaluated in 8-, 11-, and 13-year-olds. Children heard lists of words that were either semantic (e.g., bed, rest, wake …) or phonological associates (e.g., pole, bowl, hole …) of a critical unpresented word (e.g., sleep, roll), respectively. A semantic false memory was defined as false recognition of a semantically related but unpresented word. A phonological false memory was defined as false recognition of a phonologically related but unpresented word. False memories in the two tasks showed opposite developmental trends, increasing with age for semantic relatedness and decreasing with age for phonological relatedness.     

Presentation duration and false recall for semantic and phonological associates

Two experiments examined false recall for lists of semantically and phonologically associated words as a function of presentation duration. Veridical recall increased with long exposure durations for all lists. For semantically associated lists, false recall increased from 20-250 ms, then decreased. There was a high level of false recall with 20 ms durations for phonologically associated lists (47 and 44% for Experiments 1 and 2, respectively), which declined as duration increased. In Experiment 2, for lists presented at 20 and 50 ms rates, false recall given zero correct recall was observed frequently, suggesting that conscious recollection of studied words was not necessary for phonological false memory. Differences between phonologically and semantically associated lists were consistent with a feature integration model based on automatic initial processing of phonetic features of words.     

False memories in children. Evidence for a shift from phonological to semantic associations

Memory illusions in children of three age groups (5-, 8-, and 11-year-olds) were investigated using a modified version of the Deese-Roediger-McDermott (DRM) procedure. Children from each age group falsely recalled nonpresented items related to the study lists. However, the nature of the intrusions varied across the different groups. The 5-year-olds were more likely to falsely recall words that rhymed with the studied items than to recall unrelated items, whereas the 11-year-olds were more likely to falsely recall words that were semantically related to the list theme than to produce either rhyming or unrelated intrusions. Intrusions made by the 8-year-olds were equally likely to be semantic, rhyming, or unrelated to study items. The results are consistent with the notion of a developmental shift from phonological to semantic associations, leading to qualitatively different memory distortions in children of different ages.     

Hemispheric asymmetries in semantic processing: evidence from false memories for ambiguous words

We used fMRI to investigate competition during language production in two word production tasks: object naming and color naming of achromatic line drawings. Generally, fMRI activation was higher for color naming. The line drawings were followed by a word (the distractor word) that referred to either the object, a related object, or an unrelated object. The effect of the distractor word on the BOLD response was qualitatively different for the two tasks. The activation pattern suggests two different kinds of competition during lexical retrieval: (1) Task-relevant responses (e.g., red in color naming) compete with task-irrelevant responses (i.e., the object’s name). This competition effect was dominant in prefrontal cortex. (2) Multiple task-relevant responses (i.e., target word and distractor word) compete for selection. This competition effect was dominant in ventral temporal cortex. This study provides further evidence for the distinct roles of frontal and temporal cortex in language production, while highlighting the effects of competition, albeit from different sources, in both regions.     

The effects of age and dementia of the Alzheimer's type on phonological false memories

The authors conducted 3 experiments that examined the effects of age and dementia of the Alzheimer's type (DAT) on phonological false memories. In addition, the study was designed to investigate the role of inhibitory control in mediating phonological false memories. In Experiment 1, both young-old and old-old participants exhibited increased susceptibility to false remembering, compared with young adults. In Experiment 2, auditory Stroop interference was used as an index of inhibitory abilities and was found to account for a significant percentage of the variance in false recollection. Experiment 3 provided converging evidence for the importance of inhibitory control in phonological false memories by demonstrating that DAT patients are more susceptible to false recall and recognition than healthy older adults. The results are discussed within the inhibitory deficit framework of cognitive aging.     

The organisation of musical semantic memory: Evidence from false memories for familiar songs

By adapting a well-known paradigm for studying memory for words—the Deese-Roediger-McDermott or DRM paradigm (Deese, 1959, Roediger & McDermott, 1995)—the two experiments reported here explore memory for song titles and song clips. Participants were presented with five song titles (Experiment 1a) or five 30-second song clips (Experiment 1b) for each of nine popular artists (e.g., Robbie Williams). The most popular song identified for each artist in a pilot task was omitted from the sets of titles/clips. Following a distractor task, participants were asked to write down as many of the songs as they could recall. They were also asked to return a week later and complete a second recall task. Participants falsely recalled a significant number of the related but non-presented songs in both experiments and this increased a week later, while correct recall for presented items decreased. The results are discussed in terms of theory for musical memory as well as in the context of providing a novel method for exploring the organisation of musical memory.     

Episodic generation can cause semantic forgetting: Retrieval-induced forgetting of false memories

In two experiments, we tested whether false recognition and false recall were prone to retrieval-induced forgetting, using the retrieval practice paradigm (Anderson, Bjork, & Bjork, 1994). Participants encoded lists of cue-target word pairs associated with a nonpresented, critical theme word and then engaged in retrieval practice for half of the word pairs from half of the lists. As expected, unpracticed targets from practiced lists were recognized (Experiment 1) and recalled (Experiment 2) less well than those from unpracticed lists. In addition, false recognition and false recall of critical items associated with practiced lists was lower than false recognition and false recall of items associated with unpracticed lists. We argue that false memories are prone to inhibitory mechanisms engendered by the retrieval practice paradigm. The results are consistent with the claim that semantically activated critical themes interfere with the episodic retrieval of list words and that inhibition decreases the activation level of these interfering memory representations during retrieval practice.     

Similar phenomena,different mechanisms: Semantic and phonological false memories are produced by independent mechanisms

The Deese/Roediger-McDermott paradigm can produce high levels of false remembering for lists of both semantic and phonological associates. The present study investigated whether similar mechanisms mediate false memories with these two types of lists. Experiment 1 measured the relationship between levels of false memory obtained with lists of semantic and phonological associates. The results indicated little correlation between false memories generated with the two types of associates. Experiment 2 used a between-subjects design to determine whether the absence of a significant correlation in Experiment 1 was a consequence of the relatively low levels of false memory observed in that experiment. The results indicated similar proportions of false memories in Experiments 1 and 2, suggesting that the within-subjects design in Experiment 1 did not reduce the overall levels of false recall or recognition. The results are discussed in terms of their implications for the independence of the mechanisms mediating different types of false memories.     

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 brand names

Using the Deese–Roediger–McDermott (DRM) paradigm, participants are presented with lists of associated words (e.g., bed, awake, night etc). Subsequently, they reliably have false memories for related but non‐presented words (e.g. SLEEP). The present study investigated whether false memories could be created for brand names (e.g. Morrisons, Sainsbury's, Waitrose and TESCO) using the DRM paradigm and whether the effect was reduced if stimuli were presented in brand appropriate fonts compared with a plain font. Participants were presented with lists of brand names in plain or brand appropriate fonts, followed by a distractor task or free recall. Finally, they had a recognition task. Both false recall and false recognition of non‐presented brand names occurred. Brand specific fonts at study had no effect on recall but increased overall recognition. There was considerable variability in levels of false recall and false recognition amongst lists and across participants and reasons for this are discussed. Copyright © 2010 John Wiley & Sons, Ltd.     

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 emotional false memories

Eight- and 12-year-old children were presented with neutral and negative emotional Deese-Roediger-McDermott lists equated on familiarity and associative strength. Both recall and recognition (A') measures were obtained. Recall measures exhibited the usual age increments in true and false recollection. True neutral items were better recalled and recognized than true negative emotional items. Although the children showed more false recall for neutral than for negative emotional lists, false recognition was higher for negative emotional than for neutral items. A' analyses also showed that whereas true neutral information and false neutral information were easily discriminated by children regardless of age, the same was not the case for true and false negative emotional information. Together, these results suggest that although children may be able to censor negative emotional information at recall, such information promotes relational processing in children's memory, making true and false emotional information less discriminable overall.     

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).     

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.     

Social influence and mental routes to the production of authentic false memories and inauthentic false memories

Two studies assessed the extent to which people incorporated false facts provided by bogus others into their own recognition memory reports, and how these false memory reports were affected by: (a) truth of the information in others’ summaries supporting the false facts, (b) motivation to process stories and summaries, (c) source credibility, and (d) ease of remembering original facts. False memory report frequency increased when false facts in a summary were supported by true information and varied inversely with the ease with which original facts could be remembered. Results from a measure probing participants’ memory perceptions suggest that some false memories are authentic: People sometimes lack awareness of both the incorporation of false facts into their memory reports and where the false facts came from. However, many false memories are inauthentic: Despite reporting a false memory, people sometimes retain knowledge of the original stimulus and/or the origin of false facts.     

Encoding context and false recognition memories

False recognition of an extralist word that is thematically related to all words of a study list may reflect internal activation of the theme word during encoding followed by impaired source monitoring at retrieval, that is, difficulty in determining whether the word had actually been experienced or merely thought of. To assist source monitoring, distinctive visual or verbal contexts were added to study words at input. Both types of context produced similar effects: False alarms to theme-word (critical) lures were reduced; remember judgements of critical lures called old were lower; and if contextual information had been added to lists, subjects indicated as much for list items and associated critical foils identified as old. The visual and verbal contexts used in the present studies were held to disrupt semantic categorisation of list words at input and to facilitate source monitoring at output.     

Encoding context and false recognition memories

False recognition of an extralist word that is thematically related to all words of a study list may reflect internal activation of the theme word during encoding followed by impaired source monitoring at retrieval, that is, difficulty in determining whether the word had actually been experienced or merely thought of. To assist source monitoring, distinctive visual or verbal contexts were added to study words at input. Both types of context produced similar effects: False alarms to theme‐word (critical) lures were reduced; remember judgements of critical lures called old were lower; and if contextual information had been added to lists, subjects indicated as much for list items and associated critical foils identified as old. The visual and verbal contexts used in the present studies were held to disrupt semantic categorisation of list words at input and to facilitate source monitoring at output.     

Building false memories without suggestions

People can come to remember doing things they have never done. The question we asked in this study is whether people can systematically come to remember performing actions they never really did, in the absence of any suggestion from the experimenter. People built LEGO vehicles, performing some steps but not others. For half the people, all the pieces needed to assemble each vehicle were laid out in order in front of them while they did the building; for the other half, the pieces were hidden from view. The next day, everyone returned for a surprise recognition test. People falsely and confidently remembered having carried out steps they did not; those who saw all the pieces while they built each vehicle were more likely to correctly remember performing steps they did perform but equally likely to falsely remember performing steps they did not. We explain our results using the source monitoring framework: People used the relationships between actions to internally generate the missing, related actions, later mistaking that information for genuine experience.