Short-term false memories vary as a function of list type.

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.

Semantic and phonological false memory: A review of theory and data

The Distinctions of False and Fuzzy Memories

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.

Relation between Deese-Roediger-Mcdermott recall measures of false memory and the fading affect bias

When a person processes a list of items in a survival context, true and false memory for the items increase. We propose a theoretical explanation for these findings using fuzzy trace theory (FTT). According to FTT, memories are stored in parallel as verbatim and gist traces where verbatim traces represent surface details and gist traces represent semantic content. Verbatim traces support true memories, while gist traces support both true and false memories. FTT predicts that deep processing creates stronger gist traces than shallow processing. This is because deep processing emphasizes the shared meaning of the items in a list. Hence, survival processing likely strengthens gist traces because it requires meaningful processing of how much items adhere to the shared function of aiding survival. Therefore, that survival processing increases true and false memory is consistent with FTT. We also discuss FTT’s predictions of developmental differences in survival processing.

Background: Previous experimental work demonstrates that acute exercise may enhance episodic memory performance. However, limited research has examined the extent to which acute exercise influences false episodic memory production, and no studies, to date, have examined whether there is an intensity-specific effect of acute exercise on both true episodic and false episodic memories. Thus, the present experiment evaluated the effects of intensity-specific acute exercise on episodic memory and false episodic memory.Methods: A three-arm, parallel, between-group randomized controlled trial was employed in the University setting, with participants (N=60; Mage= 20.8 years) randomized into a moderate intensity exercise group (15-minute bout of treadmill exercise at 50% heart rate reserve), a high intensity exercise group (15-minute bout of treadmill exercise at 80% heart rate reserve), or a control group (time-matched period of sitting). True episodic and false episodic memory were both assessed using 6 word-lists from the Deese-Roediger-McDermott (DRM) paradigm, including both a short-term recall and a delayed memory recognition assessment. Results: For the number of words recalled across each of the 6 lists, there was a significant main effect for list (P<0.001, η2p=0.15), marginally significant main effect for group (P=0.07, η2p=0.09), but no list by group interaction effect (P=0.44, η2p=0.03). Those in the high-intensity exercise group recalled significantly (P<0.05) more words than the control group. For the false episodic word recall, across various lists, high-intensity acute exercise was associated with a greater rate of false episodic memories. For the memory recognition task, there was no main effect for word type (P=0.46, η2p=0.01), group (P=0.4443, η2p=.03), word type by group interaction (P=0.44,η2p=0.03), recall by group interaction (P=0.4441, η2p=0.04), or word type by recall by group interaction (P=0.32, η2p=0.04). However, there was a main effect for recall (P<0.001, η2p=.54)and a word type by recall interaction (P<0.001, η2p=0.77).Conclusion: These findings suggest that acute high-intensity exercise may enhance true episodic memories, and, possibly, also increase the rate of false episodic memories. We discuss these findings in the context of how different acute exercise intensities may have unique and differential effects on underlying mechanistic processes related to true and false episodic memory.

Neural correlates underlying true and false associative 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.

Deese/Roediger/McDermott (DRM) list words can share either semantic relatedness or phonological resemblance with their critical distractor. We review three lines of evidence in which semantic and phonological DRM illusions have been compared: (a) studies in which the two illusions were tracked in populations with different semantic or surface memory abilities; (b) studies that investigated the effects of manipulations that target semantic content or surface content or both; and (c) studies that examined hybrid forms of the illusion in which there was both semantic and surface resemblance between false memories and actual experiences. The three lines of evidence showed that semantic and phonological DRM illusions display dissociative patterns in most instances, indicating that they are two distinct types of false memories. We also discussed how the two major theories of the DRM illusion, fuzzy-trace theory and the activation/monitoring framework, account for the underlying mechanisms for the semantic and phonological illusions.

Fuzzy-trace theory and source monitoring: An evaluation of theory and false-memory data

Insight accompanied by an 'aha!' experience has a mnemonic effect. Previous studies of insight have often focused on the mnemonic effect of insight on veridical memories, while the effect of insight on false memories is not known. More understanding of the mnemonic effect of insight on false memories could have implications for the mechanism of insightful mnemonic effects. The present research examined whether insight has a mnemonic effect on false memories. Participants were asked to perform Chinese verbal compound remote associate (CRA) tasks and then complete the Deese-Roediger-McDermott (DRM) task, the critical lure of which was also the solution to the Chinese CRA problem. Compared to non-insight, insight was associated with a lower critical lures rate in Experiment 1 and with lower critical lures and unrelated words rates in Experiment 2 when the presentation of DRM list words was random. Giving a warning before DRM tasks could reduce the critical lures rate of non-insight but had little effect on insightful solutions in Experiment 3. These findings indicate that insight can reduce false memories.

ABSTRACTIn the present experiment, we investigated whether warnings provided at the time of retrieval would reduce emotional false memories in the Deese-Roediger-McDermott (DRM) paradigm. The provision of retrieval warnings allowed us to test specific predictions based on the associative theories (e.g., Activation-Monitoring Theory; AMT) and Fuzzy-Trace Theory (FTT) that have been used to account for false memories in the DRM paradigm. Participants were randomly assigned to either a no-warning group or a retrieval-warning group. In each group, mood-induction procedures were used to elicit a positive, negative, or neutral mood and participants were then presented with word lists comprised of positive, negative, or neutral words. Retrieval warnings reduced false recognition, regardless of the valence of the to-be-remembered information or participants’ mood. Consistent with the associative theories’ predictions, within the warning condition, positive moods yielded greater false recognition for positive critical lures, and negative moods yielded greater false recognition for negative critical lures, compared to neutral moods. These findings have important practical implications for our understanding of the effect of mood on memory.

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.

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.