False Recollection Research Articles

EFFECT OF AUTOBIOGRAPHICAL FALSE MEMORY ON THE COMPLEXITY OF NEURAL OSCILLATIONS

Memory is an imperfect record of past experiences that enables us to operate in the present and think about the future. Although various factors may give a chance to a false recollection of information that may not occur. These false memories are formed based on various neuro-cognitive processes the underlying mechanism still needs to be well understood. Considering the extended searching when no memory trace is found, we hypothesized that the self-similarities in the brain activations must be higher during false memory recalls. Therefore, a language-free task based on autobiographical brand images was designed using the Deese–Roediger–McDermott (DRM) paradigm. The task was then tested on 24 healthy participants while the brain activities during the test were recorded using a 32-channel EEG system. Subsequently, the self-similarities in the brain activity pattern were estimated by taking the fractal dimension (FD) of the cleaned EEG data. Statistical analysis showed a significant increase in complexity during false memory recalls as compared to true memory recalls prominent in the frontal regions. Interestingly, the EEG findings were consistent in both genders and significantly correlated with subjects’ accuracy rates and reaction times (RTs) to recall.

Self-Enhanced False Memory Across the Life Span.

The role of self in veridical memory has been extensively studied, but what is the role of self in false memory development across the life span? The current study examined the impact of self-reference on associative false memory in children, younger adults, and older adults, and further investigated possible mechanisms concerning how self-reference might affect false memory in different age groups. Combining a self-reference manipulation with the Deese/Roediger-McDermott (DRM) paradigm, children, younger adults, and older adults encoded DRM word lists as paired with their own name, another person's name, or a red square. Later their true and false recognition memory as well as recollection and familiarity were measured. A self-enhanced false memory effect was found in all age groups. That is, participants generated more false memories in the self-reference condition relative to the other-reference and neutral conditions. Furthermore, when examining its underlying memory mechanisms, we found that self-reference mainly increased false recollection in younger adults but facilitated familiarity of critical lures in older adults. Although self-reference increases false memory in both younger and older adults, the underlying mechanisms are different in that older adults have more self-relevant false familiarity while younger adults generate more self-relevant phantom recollection. The current study also has implications for eyewitness reports, suggesting that the self-relevance of memory may be one relevant factor to consider when evaluating potential risk factors of false memory.

Fornix white matter microstructure differentially predicts false recollection rates in older and younger adults

Healthy aging is accompanied by increased false remembering in addition to reduced successful remembering in older adults. Neuroimaging studies implicate age-related differences in the involvement of medial temporal lobe and fronto-parietal regions in mediating highly confident false recollection. However, no studies have directly examined the relationship between white matter microstructure and false recollection in younger and older adults. Using diffusion-weighted imaging and probabilistic tractography, we examined how white matter microstructure within tracts connecting the hippocampus and the fronto-parietal retrieval network contribute to false recollection rates in healthy younger and older adults. We found only white matter microstructure within the fornix contributed to false recollection rates, and this relationship was specific to older adults. Fornix white matter microstructure did not contribute to true recollection rate, nor did common white matter contribute to false recollection, suggesting fornix microstructure is explicitly associated with highly confident false memories in our sample of older adults. These findings underlie the importance of examining microstructural correlates associated with false recollection in younger and older adults.

A continuous source reinstatement model of true and false recollection.

In studies of false recognition, subjects not only endorse items that they have never seen, but they also make subjective judgments that they remember consciously experiencing them. This is a difficult problem for most models of recognition memory, as they propose that false memories should be based on familiarity, not recollection. We present a new computational model of recollection, based on the Recognition through Semantic Synchronization (RSS) model of Johns, Jones, & Mewhort (Cognitive Psychology, 2012, 65, 486), and fuzzy trace theory (Brainerd & Reyna, Current Directions in Psychological Science, 2002, 11, 164), that offers a solution to this problem. In addition to standard true and false recognition results, the model successfully extends to explain multiple studies on both true and false recollection. This work suggests that recollection does not have to be thought of as a separate process from recognition, but instead as one that is reliant upon different information sources. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Creating emotional false recollections: Perceptual recombination and conceptual fluency mechanisms.

We investigated the impact of 2 hypothetical mechanisms of episodic memory reconstruction-perceptual recombination and conceptual fluency-on objectively measured recollection accuracy and false recollections of neutral and emotional stimuli. Participants encoded negative, neutral, and positive pictures depicting objects and scenes (i.e., target pictures), each accompanied with a descriptive verbal label (e.g., "boy crying at funeral," "wooden basket on floor," "four chimpanzees laughing together"). Next, they encoded fragmented pictures of some of the scenes they did and did not earlier see (perceptual misinformation), or they received multiple presentations of the corresponding verbal labels (conceptual misinformation). Recollection of target pictures was then tested, using labels as retrieval cues. We had three key findings in each of two experiments. First, as in our prior work, both perceptual and conceptual misinformation significantly increased false recollection judgments of nonstudied pictures, including high-confidence errors. These effects implicate perceptual recombination and conceptual fluency mechanisms. Second, these misinformation effects generalized across all emotional categories, implicating separable roles of these two mechanisms on emotional recollections. Finally, conceptual misinformation was less likely to influence negative than neutral recollection errors, providing new evidence that emotion can improve retrieval monitoring accuracy and reduce false memories based on conceptual fluency (i.e., an emotional distinctiveness heuristic). (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Developmental trends in children’s use of different monitoring processes to avoid false memories

We examined the development of memory editing to avoid false recollection. Pre-K/Kindergarteners (M = 5;11), 1st graders (M = 6;11), 3rd graders (M = 8;2) and adults (M = 18;9) studied words and pictures and took recollection tests. In the non-exclusive condition, some items were studied in both formats, so that test performance required the selective recollection and monitoring of targeted word or picture information (diagnostic monitoring). In the exclusive condition, items were studied as words or pictures, so that non-target recollection allowed for the logical rejection of the item from the target format (disqualifying monitoring). We found significant developmental differences in recollection accuracy for words, but all participants used picture recollections to suppress false recollection on non-exclusive (diagnostic monitoring) and exclusive tests (disqualifying monitoring). Therefore, children’s propensity for false recollection errors may be related to recollecting and monitoring relatively nondistinctive target information, instead of monitoring processes in general.

Supplemental Material for Creating Emotional False Recollections: Perceptual Recombination and Conceptual Fluency Mechanisms

Supplemental Material for Creating Emotional False Recollections: Perceptual Recombination and Conceptual Fluency Mechanisms

Déjà vu and the entorhinal cortex: dissociating recollective from familiarity disruptions in a single case patient

ABSTRACT Past research has demonstrated a relationship between déjà vu and the entorhinal cortex in patients with wider medial temporal lobe damage. The aim of the present research was to investigate this crucial link in a patient (MR) with a selective lesion to the left lateral entorhinal cortex to provide a more direct exploration of this relationship. Two experiments investigated the experiences of déjà vécu (using the IDEA questionnaire) and déjà vu (using an adapted DRM paradigm) in MR and a set of matched controls. The results demonstrated that MR had quantitatively more and qualitatively richer recollective experiences of déjà vécu. In addition, under laboratory-based déjà vu conditions designed to elicit both false recollection (critical lures) and false familiarity (weakly-associated lures), MR only revealed greater memory impairments for the latter. The present results are therefore the first to demonstrate a direct relationship between the entorhinal cortex and the experience of both déjà vu and déjà vécu. They furthermore suggest that the entorhinal cortex is involved in both weakly-associative false memory as well as strongly-associative memory under conditions that promote familiarity-based processing.

Δ9-Tetrahydrocannabinol at Retrieval Drives False Recollection of Neutral and Emotional Memories

BackgroundIt is well established that the main psychoactive constituent of cannabis, Δ9-tetrahydrocannabinol (THC), impairs episodic memory encoding and modulates emotional processing, but little is known about the impact of THC during the retrieval of emotional episodic memories. With the rise of cannabis to treat medical conditions, including those characterized by emotional and episodic memory disturbances, there is an urgent need to determine the effects of THC on memory accuracy and distortion. Here, we report the first study investigating the effects of THC during retrieval of neutral and emotional episodic memories. MethodsUsing a double-blind, placebo-controlled, within-subjects design, healthy volunteers (N = 23) viewed negative, neutral, and positive pictures (emotional memory task) and lists of semantically related words (false memory task). Forty-eight hours later, participants ingested a capsule containing either THC (15 mg) or placebo and completed tasks to test their memories for the previously studied pictures and words. ResultsTHC during retrieval did not reduce the number of correct responses to studied items. Instead, it robustly increased false recollection on both the emotional memory and false memory tasks. This effect was found for both neutral and emotional items. ConclusionsThese findings show that THC has adverse effects during memory retrieval, distorting both neutral and emotional memories. Coupled with THC’s known effects during encoding, these new retrieval findings are important in light of the spreading acceptance of cannabis.

Activating Aging Stereotypes Increases Source Recollection Confusions in Older Adults: Effect at Encoding but Not Retrieval.

Activating aging stereotypes can impair older adult performance on episodic memory tasks, an effect attributed to stereotype threat. Here, we report the first study comparing the effects of explicitly activating aging stereotypes at encoding versus retrieval on recollection accuracy in older adults. During the encoding phase, older adults made semantic judgments about words, and during the retrieval phase, they had to recollect these judgments. To manipulate stereotype activation, participants read about aging-related decline (stereotype condition) or an aging-neutral passage (control condition), either before encoding or after encoding but before retrieval. We also assessed stereotype effects on metacognitive beliefs and two secondary tasks (working memory, general knowledge) administered after the recollection task. Stereotype activation at encoding, but not retrieval, significantly increased recollection confusion scores compared to the control condition. Stereotype activation also increased self-reports of cognitive decline with aging, but it did not reliably impact task-related metacognitive assessments or accuracy on the secondary tasks. Explicitly activating aging stereotypes at encoding increases the likelihood of false recollection in older adults, potentially by diminishing encoding processes. Stereotype activation also influenced global metacognitive assessments, but this effect may be unrelated to the effect of stereotypes on recollection accuracy.

How do associative and phonemic overlap interact to boost illusory recollection?

ABSTRACTThis project investigated the underlying mechanisms that boost false remember responses when participants receive study words that are both semantically and phonologically similar to a critical lure. Participants completed a memory task in which they were presented with a list of words all associated with a critical lure. Included within the list of semantic associates was a target that was either semantically associated (e.g., yawn) to the critical lure (e.g., sleep) or shared the initial (e.g., slam) or final (e.g., beep) phoneme(s) with the critical lure. After hearing the list, participants recalled each list item and indicated whether they just knew it was on the list or if they instead recollected specific contextual details of that item’s presentation. We found that inserting an initial phonemic overlap target boosted experiences of recollection, but only when semantically related associates were presented beforehand. The results are consistent with models of spoken word recognition and show that established semantic context plus initial phonemic overlap play important roles in boosting false recollection.

Is negative self-referent bias an endophenotype for depression? An fMRI study of emotional self-referent words in twins at high vs. low risk of depression

BackgroundNegative cognitive bias and aberrant neural processing of self-referent emotional words seem to be trait-marks of depression. However, it is unclear whether these neurocognitive changes are present in unaffected first-degree relatives and constitute an illness endophenotype. MethodsFifty-three healthy, never-depressed monozygotic or dizygotic twins with a co-twin history of depression (high-risk group: n = 26) or no first-degree family history of depression (low-risk group: n = 27) underwent neurocognitive testing and functional magnetic imaging (fMRI) as part of a follow-up cohort study. Participants performed a self-referent emotional word categorisation task and free word recall task followed by a recognition task during fMRI. Participants also completed questionnaires assessing mood, personality traits and coping strategies. ResultsHigh-risk and low-risk twins (age, mean ± SD: 40 ± 11) were well-balanced for demographic variables, mood, coping and neuroticism. High-risk twins showed lower accuracy during self-referent categorisation of emotional words independent of valence and more false recollections of negative words than low-risk twins during free recall. Functional MRI yielded no differences between high-risk and low-risk twins in retrieval-specific neural activity for positive or negative words or during the recognition of negative versus positive words within the hippocampus or prefrontal cortex. ConclusionsThe subtle display of negative recall bias is consistent with the hypothesis that self-referent negative memory bias is an endophenotype for depression. High-risk twins’ lower categorisation accuracy adds to the evidence for valence-independent cognitive deficits in individuals at familial risk for depression.

Variation in the standard deviation of the lure rating distribution: Implications for estimates of recollection probability

In word recognition semantic priming of test words increased the false-alarm rate and the mean of confidence ratings to lures. Such priming also increased the standard deviation of confidence ratings to lures and the slope of the z-ROC function, suggesting that the priming increased the standard deviation of the lure evidence distribution. The Unequal Variance Signal Detection (UVSD) model interpreted the priming as increasing the standard deviation of the lure evidence distribution. Without additional parameters the Dual Process Signal Detection (DPSD) model could only accommodate the results by fitting the data for related and unrelated primes separately, interpreting the priming, implausibly, as decreasing the probability of target recollection (DPSD). With an additional parameter, for the probability of false (lure) recollection the model could fit the data for related and unrelated primes together, interpreting the priming as increasing the probability of false recollection. These results suggest that DPSD estimates of target recollection probability will decrease with increases in the lure confidence/evidence standard deviation unless a parameter is included for false recollection. Unfortunately the size of a given lure confidence/evidence standard deviation relative to other possible lure confidence/evidence standard deviations is often unspecified by context. Hence the model often has no way of estimating false recollection probability and thereby correcting its estimates of target recollection probability.

The neurocognitive basis of borrowed context information

Falsely remembered items can be accompanied by episodic context retrieval. This finding is difficult to explain because there is no episode that binds the remembered item to the experimenter-controlled context features. The current study examines the neural correlates of false context retrieval when the context features can be traced to encoding episodes of semantically-similar items. Our neuroimaging results support a “dissociated source” mechanism for context borrowing in false memory. We found that parahippocampal cortex (PHc) activation, thought to indicate context retrieval, was greater during trials that involved context borrowing (an incorrect, but plausible source decision) than during baseline correct context retrieval. In contrast, hippocampal activation, thought to indicate retrieval of an episodic binding, was stronger during correct source retrieval than during context borrowing. Vivid context retrieval during false recollection experiences was also indicated by increased activation in visual perceptual regions for context borrowing as compared to other incorrect source judgments. The pattern of findings suggests that context borrowing can arise when unusually strong activation of a semantically-related item's contextual features drives relatively weak retrieval of the associated episodic binding with failure to confirm the item information within that binding. This dissociated source retrieval mechanism suggests that context-driven episodic retrieval does not necessarily lead to retrieval of specific item details. That is, source information can be retrieved in the absence of item memory.

Assumptions behind scoring source versus item memory: Effects of age, hippocampal lesions and mild memory problems

Source monitoring paradigms have been used to separate: 1) the probability of recognising an item (Item memory) and 2) the probability of remembering the context in which that item was previously encountered (Source memory), conditional on it being recognised. Multinomial Processing Tree (MPT) models are an effective way to estimate these conditional probabilities. Moreover, MPTs make explicit the assumptions behind different ways to parameterise Item and Source memory. Using data from six independent groups across two different paradigms, we show that one would draw different conclusions about the effects of age, age-related memory problems and hippocampal lesions on Item and Source memory, depending on the use of: 1) standard accuracy calculation vs MPT analysis, and 2) two different MPT models. The MPT results were more consistent than standard accuracy calculations, and furnished additional parameters that can be interpreted in terms of, for example, false recollection or missed encoding. Moreover, a new MPT structure that allowed for separate memory representations (one for item information and one for item-plus-source information; the Source-Item model) fit the data better, and provided a different pattern of significant differences in parameters, than the more conventional MPT structure in which source information is a subset of item information (the Item-Source model). Nonetheless, there is no theory-neutral way of scoring data, and thus proper examination of the assumptions underlying the scoring of source monitoring paradigms is necessary before theoretical conclusions can be drawn.

Two mechanisms of constructive recollection: Perceptual recombination and conceptual fluency.

Recollection is constructive and prone to distortion, but the mechanisms through which recollections can become embellished with rich yet illusory details are still debated. According to the conceptual fluency hypothesis, abstract semantic or conceptual activation increases the familiarity of a nonstudied event, causing one to falsely attribute imagined features to actual perception. In contrast, according to the perceptual recombination hypothesis, details from actually perceived events are partially recollected and become erroneously bound to a nonstudied event, again causing a detailed yet false recollection. Here, we report the first experiments aimed at disentangling these 2 mechanisms. Participants imagined pictures of common objects, and then they saw an actual picture of some of the imagined objects. We next presented misinformation associated with these studied items, designed to increase conceptual fluency (i.e., semantically related words) or perceptual recombination (i.e., perceptually similar picture fragments). Finally, we tested recollection for the originally seen pictures using verbal labels as retrieval cues. Consistent with conceptual fluency, processing-related words increased false recollection of pictures that were never seen, and consistent with perceptual recombination, processing picture fragments further increased false recollection. We also found that conceptual fluency was more short-lived than perceptual recombination, further dissociating these 2 mechanisms. These experiments provide strong evidence that conceptual fluency and perceptual recombination independently contribute to the constructive aspects of recollection. (PsycINFO Database Record

Invited commentary on Brewin and Andrews (2016)

SummaryBrewin and Andrews (2016) make many cogent observations on the state of knowledge about the development of false autobiographical beliefs and false recollections. Owing to inconsistent use of terminology and imprecise definitions, the framework they propose does not clearly map onto the studies that are summarized, making the resulting estimates of the magnitude of effects across studies unconvincing. A singular focus on the development of ‘full memories’ is not explained, and the key role of autobiographical belief in influencing behavior is underemphasized. Furthermore, the legal applications discussed are not well defined and are limited in scope. Fostering false belief or false imagery for events such as childhood abuse is unacceptable, whether or not suggested events come to be experienced as vivid believed recollections. Copyright © 2016 John Wiley & Sons, Ltd.

Memory Distortion and Its Avoidance: An Event-Related Potentials Study on False Recognition and Correct Rejection.

Memory researchers have long been captivated by the nature of memory distortions and have made efforts to identify the neural correlates of true and false memories. However, the underlying mechanisms of avoiding false memories by correctly rejecting related lures remains underexplored. In this study, we employed a variant of the Deese/Roediger-McDermott paradigm to explore neural signatures of committing and avoiding false memories. ERP were obtained for True recognition, False recognition, Correct rejection of new items, and, more importantly, Correct rejection of related lures. With these ERP data, early-frontal, left-parietal, and late right-frontal old/new effects (associated with familiarity, recollection, and monitoring processes, respectively) were analysed. Results indicated that there were similar patterns for True and False recognition in all three old/new effects analysed in our study. Also, False recognition and Correct rejection of related lures activities seemed to share common underlying familiarity-based processes. The ERP similarities between False recognition and Correct rejection of related lures disappeared when recollection processes were examined because only False recognition presented a parietal old/new effect. This finding supported the view that actual false recollections underlie false memories, providing evidence consistent with previous behavioural research and with most ERP and neuroimaging studies. Later, with the onset of monitoring processes, False recognition and Correct rejection of related lures waveforms presented, again, clearly dissociated patterns. Specifically, False recognition and True recognition showed more positive going patterns than Correct rejection of related lures signal and Correct rejection of new items signature. Since False recognition and Correct rejection of related lures triggered familiarity-recognition processes, our results suggest that deciding which items are studied is based more on recollection processes, which are later supported by monitoring processes. Results are discussed in terms of Activation-Monitoring Framework and Fuzzy Trace-Theory, the most prominent explanatory theories of false memory raised with the Deese/Roediger-McDermott paradigm.

What's the gist? The influence of schemas on the neural correlates underlying true and false memories

The current study used a novel scene paradigm to investigate the role of encoding schemas on memory. Specifically, the study examined the influence of a strong encoding schema on retrieval of both schematic and non-schematic information, as well as false memories for information associated with the schema. Additionally, the separate roles of recollection and familiarity in both veridical and false memory retrieval were examined. The study identified several novel results. First, while many common neural regions mediated both schematic and non-schematic retrieval success, schematic recollection exhibited greater activation in visual cortex and hippocampus, regions commonly shown to mediate detailed retrieval. More effortful cognitive control regions in the prefrontal and parietal cortices, on the other hand, supported non-schematic recollection, while lateral temporal cortices supported familiarity-based retrieval of non-schematic items. Second, both true and false recollection, as well as familiarity, were mediated by activity in left middle temporal gyrus, a region associated with semantic processing and retrieval of schematic gist. Moreover, activity in this region was greater for both false recollection and false familiarity, suggesting a greater reliance on lateral temporal cortices for retrieval of illusory memories, irrespective of memory strength. Consistent with previous false memory studies, visual cortex showed increased activity for true compared to false recollection, suggesting that visual cortices are critical for distinguishing between previously viewed targets and related lures at retrieval. Additionally, the absence of common visual activity between true and false retrieval suggests that, unlike previous studies utilizing visual stimuli, when false memories are predicated on schematic gist and not perceptual overlap, there is little reliance on visual processes during false memory retrieval. Finally, the medial temporal lobe exhibited an interesting dissociation, showing greater activity for true compared to false recollection, as well as for false compared to true familiarity. These results provided an indication as to how different types of items are retrieved when studied within a highly schematic context. Results both replicate and extend previous true and false memory findings, supporting the Fuzzy Trace Theory.

Reduced effects of pictorial distinctiveness on false memory following dynamic visual noise

ABSTRACTHigh levels of false recognition for non-presented items typically occur following exposure to lists of associated words. These false recognition effects can be reduced by making the studied items more distinctive by the presentation of pictures during encoding. One explanation of this is that during recognition, participants expect or attempt to retrieve distinctive pictorial information in order to evaluate the study status of the test item. If this involves the retrieval and use of visual imagery, then interfering with imagery processing should reduce the effectiveness of pictorial information in false memory reduction. In the current experiment, visual-imagery processing was disrupted at retrieval by the use of dynamic visual noise (DVN). It was found that effects of DVN dissociated true from false memory. Memory for studied words was not influenced by the presence of an interfering noise field. However, false memory was increased and the effects of picture-induced distinctiveness was eliminated. DVN also increased false recollection and remember responses to unstudied items.