When true memory availability promotes false memory: Evidence from confabulating patients

In the Deese-Roediger-McDermott (DRM) paradigm, participants falsely recall or recognize a nonpresented word (critical lure), highly associated with previously studied words. As numerous DRM studies have found a robust false memory effect at the behavioural level, event-related potentials (ERPs) studies have searched for possible overlapping in brain electrical activity between true and false memory. Using the DRM paradigm, the present experiment manipulated the sensory modality of stimulus presentation (auditory vs. visual) in the study phase to analyse the effect of modality match between study and test on true and false recognition. Words were therefore presented either visually or auditorily at study and always visually at test. True recognition was found to be significantly higher in the modality 'match' condition (visual-visual) than in the 'mismatch' condition (auditory-visual), whereas there was no modality-match effect on false recognition of critical lures. A general, overlapping was found between ERP correlates of true and false recognition: FN400 (300-500 ms), left-parietal (400-800 ms) and late right-frontal (1000-1500 ms) old/new effects were similar for both studied words and critical lures. No sensory modality-match effect was associated with FN400 or left-parietal old/new effects. Only the late right-frontal activity was modulated by modality manipulation, with significantly more positive ERPs in the modality-match condition. Sensory modality match of stimulus presentation, therefore, dissociated true and false recognition memory only at the behavioural level but not at the ERP level. Overall, true and false recognition memories seem to share common underlying processes.

False memories are not surprising: The subjective experience of an associative memory illusion

Memory is prone to illusions. When people are presented with lists of words associated with a non-presented critical lure, they produce a high level of false recognitions (false memories) for non-presented related stimuli indistinguishable, at the explicit level, from presented words (DRM paradigm). We assessed whether true and false DRM memories can be distinguished at the implicit level by using the autobiographical IAT (aIAT), a novel method based on indirect measures that permits to detect true autobiographical events encoded in the respondent’s mind/brain. In our experiment, after a DRM task participants performed two aIATs: the first aimed at testing implicit memory for presented words (true-memories aIAT) and the second aimed at evaluating implicit memory for critical lures (false-memories aIAT). Specifically, the two aIATs assessed the association of presented words and critical lures with the logical dimension “true.” Results showed that the aIAT detected a greater association of presented words than critical lures with the logical dimension “true.” This result indicates that although true and false DRM memories are indistinguishable at the explicit level a different association of the true and false DRM memories with the logical dimension “true” can be detected at the implicit level, and suggests that the aIAT may be a sensitive instrument to detect differences between true and false DRM memories.

False memories have been extensively investigated over the past few decades using the Deese/Roediger-McDermott (DRM) paradigm. In this paradigm, participants study lists of words associatively related to a non-presented critical lure. During a memory test, these critical lures are falsely recalled or recognized. Most studies have focused on false memories that arise when both encoding and retrieval are conducted in the same language (i.e., within-language conditions), which is typically the participant's native or first language (L1). However, much less is known about false memories when critical lures appear in the memory test in a different language than the studied lists (i.e., between-language conditions), being one of them the participant's second language (L2). The main objective of this exhaustive review was to provide an overview of the current state of research on false recognition using the DRM paradigm in between-language conditions, where languages are switched between encoding and retrieval (i.e., L1L2 versus L2L1). The results revealed a language dominance effect in between-language false memories. In other words, false recognition rates were dependent on the study language, with a trend toward higher false recognition when words were enconded in the L1 (L1L2) compared to when words were encoded in the L2 (L2L1). This review enhances our understanding of how studying words in a first or second language affects false memory in the DRM paradigm, emphasizing the significance of investigating false memory in second language speakers and the necessity for further research in the field.

We investigated the extent to which activation of specific information in associative networks during a memory task could facilitate subsequent analogical problem solving in healthy older adults as well as those with early onset Alzheimer’s disease. We also examined whether these priming effects were stronger when the activation of the critical solution term during the memory task occurred when the item was actually presented (true memories) or when this item arose due to spreading activation to a related but nonpresented item (false memory). Older adult controls (OACs) and people with Alzheimer’s disease (AD) were asked to solve 9 verbal proportional analogies, 3 of which had been primed by Deese/Roediger-McDermott lists where the critical lure (and problem solution) was presented as a word in the list (true memory), 3 of which were primed by DRM lists whose critical lures were spontaneously activated during list presentation (false memory), and 3 of which were unprimed. As expected, OACs were better (both in terms of speed and accuracy) at solving problems than people with AD and both groups were better when false memories were primes than when true memories were primes or there were no primes. There were no reliable differences between unprimed and true prime problems. These findings demonstrate that (a) priming of problem solutions extends to verbal proportional analogies in OACs and people with AD, (b) false memories are more effective at priming problem solutions than true memories, and (c) there are clear positive consequences to the production of false 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.

Introduction Although sleep has long been known to benefit memory consolidation, recent studies demonstrate that even a brief period of eyes-closed waking rest can similarly benefit a wide variety of memory types, including declarative, procedural and spatial. But sleep is argued to not only quantitatively strengthen memory traces, but also qualitatively transform them over time. The present study tested whether post-encoding waking rest affects the formation of false memories in the Deese-Roediger-McDermott (DRM) false memory paradigm, which are thought to arise from a “gist extraction” transformation of memory. We hypothesized that rest would increase false memory as measured by recall, but decrease false memory as measured by recognition. Methods In a within-subjects, counter-balanced design, N=51 participants auditorily encoded 8 DRM word lists. Each list consisted of 15 semantically-related words, all of which were derived from a central “critical lure” not heard by participants. After encoding, participants either sat quietly with their eyes closed for 15 minutes or spent an equivalent period of time completing a distractor task. Afterwards, participants were tested on their memory via both recall and recognition. False memory was defined as the false recall or recognition of “critical lure” words that had not been included on the list. Scores on the recall test were adjusted for incorrect responses, by subtracting the number of words incorrectly recalled (not including the lure words) from the number of words correctly recalled. Results Paired samples t-tests revealed that there was no significant effect of rest on false memory using either recall (t(50)=.26, p = .796) or recognition (t(50)=1.20, p = .237) tests. There was also no significant effect of rest on memory for studied words (recall: t(50)=1.32, p = .194; recognition: t(50)=0.51, p = .612). Conclusion This study indicates the possibility that waking rest does not affect certain types of qualitative memory transformation thought to occur during sleep. This includes the gist-extraction type processes underlying false memory. Potentially, rather than acting independently of each other, waking rest and sleep may act in coordination, each with distinct roles in the consolidation process. Support (if any) Intramural funding from Furman University.

False memories refer to falsely remembering something that did not happen or that happened differently. The effects of age on episodic memory underlie both the decline in real memories and the increase in false memories. But, what is the richness and what is the feeling of reality of false memories in the elderly? This mini-review on false memory in young and older adults presents the results from the literature using one of the most used paradigms in the laboratory to study false memories - the Deese-Roediger-McDermott paradigm. This paradigm generally consists in the presentation of semantically associated items-lists (words or images) related to a non-presented critical lure (e.g., bed, rest, awake …, the critical lure is sleep). During free recall or recognition tests, the participants regularly produce false memories (intrusions or false recognitions of the critical lures), increasingly with aging. We specifically ask the question of the richness of the false memory trace in young and older adults in terms of contextual associations (What-Where-When-Details binding) and phenomenological characteristics (remembering, knowing, guessing). We propose to examine this issue using a naturalistic episodic memory task via navigation in a virtual environment enriched with series of associated elements (e.g., vegetables stand) linked to non-presented critical lures (e.g., carrots). Based on preliminary results, we propose an integrative model of memory trace which can explain the differences observed between young and old people on the richness of their false memories.

The production of false recognition and the associated state of consciousness following encoding in a naturalistic context in aging

Human behavioral studies show that there is greater sensory/perceptual detail associated with true memories than false memories. We therefore hypothesized that true recognition of abstract shapes would elicit greater visual cortical activation than would false recognition. During functional magnetic resonance imaging (fMRI), participants studied exemplar shapes and later made recognition memory decisions ("old" or "new") concerning studied exemplars (old shapes), nonstudied lures (related shapes) and new shapes. Within visual processing regions, direct contrasts between true recognition ("old" response to an old shape; old-hit) and false recognition ("old" response to a related shape; related-false alarm) revealed preferential true recognition-related activity in early visual processing regions (Brodmann area (BA)17, BA18). By comparison, both true and false recognition were associated with activity in early and late (BA19, BA37) visual processing regions, the late regions potentially supporting "old" responses, independent of accuracy. Further analyses suggested that the differential early visual processing activity reflected repetition priming, a type of implicit memory. Thus, the sensory signature that distinguishes true from false recognition may not be accessible to conscious awareness.

In this study, the number of semantic associates in Deese-Roediger-McDermott (DRM) lists was varied from 4 to 14 in a modified Sternberg paradigm. The false alarm (FA) and correct rejection (CR) reaction time (RT)/memory-set size (MSS) functions of critical lures showed a cross-over interaction at approximately MSS 7, suggesting a reversal of the relative dominance between these two responses to the critical lure at this point and also indicating the location of the boundary between the sub- and supraspan MSS. For the subspan lists, FA to critical lures was slower than CR, suggesting a slow, strategic mechanism driving the false memory. Conversely, for the supraspan lists, critical lure FA was faster than its CR, suggesting a spontaneous mechanism driving the false memory. Results of two experiments showed that an automatic, fast, and a slow, controlled process could be error-prone or error-corrective, depending on the length of the DRM memory list. Thus there is a dual retrieval process in false memory as in true memory. The findings can be explained by both the activation/monitoring and the fuzzy-trace theories.

ABSTRACTWe used the Fuzzy-Trace Theory (FTT) perspective to investigate the role of context switching or reinstatement on correct and false recognition in Deese–Roediger–McDermott (DRM) and simple false memory for occurrence (FMO) tasks. In two experiments, participants studied words presented against unique picture backgrounds. The results indicated that providing specific item-context associative information in the reinstated-context test condition enhances verbatim trace retrieval of targets but does not influence their gist retrieval. In the case of false recognitions of related distracters, manipulations of retrieval context resulted in different effects across experiments, putatively because the DRM and FMO tasks involve different latent-processes implied by FTT. The results confirmed the critical role of retrieval conditions for false and correct recognition memory and showed the insights that can be gained from the process-level multinomial modelling analyses of data obtained in particular experimental paradigms.

The present study investigated the extent of mood-congruent false and true memory recognition in depression. A group of 25 patients with depression and 28 healthy controls completed a variant of the Deese-Roediger McDermott task. Four lists were read to participants in sequence, followed by a recognition task. The words in each list were associated with a central but unmentioned theme word that was either depression-relevant (i.e., loneliness), delusion-relevant (betrayal), positive (holidays), or neutral (window). Whereas it was expected to replicate the conventional mood-congruent effect in depression (better recognition of depression-relevant items), the available literature did not allow strong predictions to be made on the extent of mood-congruent false recognition in depression. Results showed that depressed patients learned emotionally charged material equally well as healthy participants but forgot significantly more neutral material. A conventional mood-congruent memory bias was not found, but relative to healthy controls, patients with depression committed more false recognition errors for emotionally charged words, particularly for depression-relevant items. The results confirm that depressed patients are biased toward emotional material. Reasons for the absence of the expected mood-congruent memory bias are discussed. It is suggested that researchers as well as clinicians should pay more attention to mood-congruent false recollection, because it may undermine the validity of autobiographic reports in depressive patients and may represent a maintenance factor for the disorder.

Only test-based manipulations can be used to help people distinguish accurate from false memories once events have been encoded. In two experiments we examined how the type of studied words (weak vs strong associates, or less vs more memorable associates) and nonstudied lure words (related vs unrelated lures) on the test list affect recognition accuracy in the Deese-Roediger-McDermott paradigm. False recognition of critical lures decreased substantially in the related-lure context, but so did correct recognition of studied words. False recognition was little affected by the studied-word manipulations. In general, participants claimed to recognise critical lures as often as weak associates or less memorable studied words but less often than either strong associates or more memorable studied words. The test-list context affected how participants classified their recognition experiences but it did not systematically change their overall memory accuracy.

Age-related changes in neural activity associated with familiarity, recollection and false recognition.