Illusory Memories Research Articles

Spatial Reconstruction and Aesthetic Expression of Feminist Narratives

The movie Song of Spring with beautiful images tells the story of a middle-aged and elderly mother and daughter after encountering sudden changes in their lives. They heal each other in their plight and redeemed each other. Director Yang Li Na uses a new female perspective to look at society, dissolving the male gaze through the female point of view and voice. She uses a beautiful mirror narrative to show the growth and image of women, revealing the historical complexes and cultural psychology of contemporary elderly women and reflecting the richness of the female world; through a dreamlike polyphony narrative, she reconstructs the narrative time and space, with real life time and space interspersed with the ever-present illusory memories, highlighting the plight of women behind the warmth; through the beautiful narrative of "prose poetry" and the poetic metaphors of beautiful romance, a gentle and serene feminist expression is presented. Based on feminist narratology, this research uses documentary and qualitative research methods to analyze the film Song of Spring reconstruction of feminist-themed films by surreal expression techniques and poetic metaphors spanning time and space, exploring the "other" perspective and gender aesthetics of feminist narratives in the film Song of Spring and the reflections on the meaning and value of women’s lives behind it.

Development of posttraumatic stress disorder symptoms after intensive care - how to prevent it?

IntroductionOver the last decade, there has been identified that critical illness survivors have high rates of psychiatric disorders such as posttraumatic stress disorder (PTSD). The experience of admission to intensive care units (ICU) and illusory memories may cause short and long-term psychological disorders.ObjectivesTo evaluate psychiatric disorders, such as PTSD, after ICU discharge, and determine the prevalence, risk factors, and prevention strategies for PTSD in these patients.Methods Non-systematic review through research in PubMed. Addicionally, a case report will be exposed, after the patient was diagnosed with SARS‑CoV‑2 and stayed in ICU for more than 30 days.Results The development of PTSD has been related to the number of adverse memories patients recall from their ICU experience. Some studies have shown that approximately 47% of patients remember real facts and 34% have illusory memories relative to their stays in the ICU. There were identified some risk factor associated to the increased risk of post-ICU PTSD, such as early post-ICU memories or psychotic experiences, pre-ICU psychopathology, benzodiazepine sedation during ICU and substantial acute stress symptoms occurring < 1 month after exposure to a traumatic stressor.ConclusionsHigh levels of anxiety and the development by patients of PTSD are being recognized as significant problems occurring after a stay in an ICU. The results of this study highlight the need to recognise the risk factors and to establish a early follow-up after ICU stay. This way is possible to identify patients who are at risk of developing acute PTSD-related symptoms, and early intervention can be institued.DisclosureNo significant relationships.

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.

Reported serial positions of true and illusory memories in the Deese/Roediger/McDermott paradigm

One of the easiest ways to induce illusory memories in the laboratory is to use the Deese–Roediger–McDermott (DRM) word-list paradigm. Researchers have used this paradigm not only to study people's memories of stimuli that were not actually presented, but also to study the phenomenological qualities of these illusions. In four experiments, the current investigation explored a phenomenological quality of illusory memories that has received almost no attention, specifically, temporality. A serial position task was incorporated into the DRM paradigm to examine temporal attributes of participants' true and false memories. Effects of list strength, presentation order, and types of warnings were examined. Results showed consistent serial position responses for true and false memories. However, only responses for illusory memories were affected by manipulations at study. The current findings thus lend support to encoding-based explanations of false recollections.

Telling true from false: cannabis users show increased susceptibility to false memories.

Previous studies on the neurocognitive impact of cannabis use have found working and declarative memory deficits that tend to normalize with abstinence. An unexplored aspect of cognitive function in chronic cannabis users is the ability to distinguish between veridical and illusory memories, a crucial aspect of reality monitoring that relies on adequate memory function and cognitive control. Using functional magnetic resonance imaging, we show that abstinent cannabis users have an increased susceptibility to false memories, failing to identify lure stimuli as events that never occurred. In addition to impaired performance, cannabis users display reduced activation in areas associated with memory processing within the lateral and medial temporal lobe (MTL), and in parietal and frontal brain regions involved in attention and performance monitoring. Furthermore, cannabis consumption was inversely correlated with MTL activity, suggesting that the drug is especially detrimental to the episodic aspects of memory. These findings indicate that cannabis users have an increased susceptibility to memory distortions even when abstinent and drug-free, suggesting a long-lasting compromise of memory and cognitive control mechanisms involved in reality monitoring.

Normative data for Italian Deese/Roediger-McDermott lists.

The present study provides norms for Deese/Roediger-McDermott (DRM) lists that were used to create false memories in native speakers of Italian. The word lists reported in this article are based on the DRM lists that have been used extensively to examine illusory memories in English speakers (Deese in Journal of Experimental Psychology, 58, 17-22, 1959; Roediger & McDermott in Journal of Experimental Psychology: Learning, Memory, & Cognition, 21, 803-814, 1995). We translated the 24 critical lures from 24 English DRM lists and created semantically associated Italian word lists that were then normed with native Italian speakers. Overall, the participants recalled 63% of the list items and 22% of the critical lures with the word lists developed. In addition, 56% of the list items and 82% of the critical lures were recognized by the participants. The present study provides a set of Italian lists that can be used by researchers interested in evaluating false memories in Italian-speaking participants.

Animal Cognition: Bumble Bees Suffer ‘False Memories’

The existence of 'false memories', where individuals remember events that they have never actually experienced, is well established in humans. Now a new study reports that insects similarly form illusory memories through merging ofmemory traces.

False memory susceptibility is correlated with categorisation ability in humans

Our memory is often surprisingly inaccurate, with errors ranging from misremembering minor details of events to generating illusory memories of entire episodes. The pervasiveness of such false memories generates a puzzle: in the face of selection pressure for accuracy of memory, how could such systematic failures have persisted over evolutionary time? It is possible that memory errors are an inevitable by-product of our adaptive memories and that semantic false memories are specifically connected to our ability to learn rules and concepts and to classify objects by category memberships. Here we test this possibility using a standard experimental false memory paradigm and inter-individual variation in verbal categorisation ability. Indeed it turns out that the error scores are significantly negatively correlated, with those individuals scoring fewer errors on the categorisation test being more susceptible to false memory intrusions in a free recall test. A similar trend, though not significant, was observed between individual categorisation ability and false memory susceptibility in a word recognition task. Our results therefore indicate that false memories, to some extent, might be a by-product of our ability to learn rules, categories and concepts.

False memory susceptibility is correlated with categorisation ability in humans.

Our memory is often surprisingly inaccurate, with errors ranging from misremembering minor details of events to generating illusory memories of entire episodes. The pervasiveness of such false memories generates a puzzle: in the face of selection pressure for accuracy of memory, how could such systematic failures have persisted over evolutionary time? It is possible that memory errors are an inevitable by-product of our adaptive memories and that semantic false memories are specifically connected to our ability to learn rules and concepts and to classify objects by category memberships. Here we test this possibility using a standard experimental false memory paradigm and inter-individual variation in verbal categorisation ability. Indeed it turns out that the error scores are significantly negatively correlated, with those individuals scoring fewer errors on the categorisation test being more susceptible to false memory intrusions in a free recall test. A similar trend, though not significant, was observed between individual categorisation ability and false memory susceptibility in a word recognition task. Our results therefore indicate that false memories, to some extent, might be a by-product of our ability to learn rules, categories and concepts.

False memory for face in short-term memory and neural activity in human amygdala

Human memory is often inaccurate. Similar to words and figures, new faces are often recognized as seen or studied items in long- and short-term memory tests; however, the neural mechanisms underlying this false memory remain elusive. In a previous fMRI study using morphed faces and a standard false memory paradigm, we found that there was a U-shaped response curve of the amygdala to old, new, and lure items. This indicates that the amygdala is more active in response to items that are salient (hit and correct rejection) compared to items that are less salient (false alarm), in terms of memory retrieval. In the present fMRI study, we determined whether the false memory for faces occurs within the short-term memory range (a few seconds), and assessed which neural correlates are involved in veridical and illusory memories. Nineteen healthy participants were scanned by 3T MRI during a short-term memory task using morphed faces. The behavioral results indicated that the occurrence of false memories was within the short-term range. We found that the amygdala displayed a U-shaped response curve to memory items, similar to those observed in our previous study. These results suggest that the amygdala plays a common role in both long- and short-term false memory for faces. We made the following conclusions: First, the amygdala is involved in detecting the saliency of items, in addition to fear, and supports goal-oriented behavior by modulating memory. Second, amygdala activity and response time might be related with a subject׳s response criterion for similar faces.

Semantic similarity between old and new items produces false alarms in recognition memory.

In everyday life, human beings can report memories of past events that did not occur or that occurred differently from the way they remember them because memory is an imperfect process of reconstruction and is prone to distortion and errors. In this recognition study using word stimuli, we investigated whether a specific operationalization of semantic similarity among concepts can modulate false memories while controlling for the possible effect of associative strength and word co-occurrence in an old-new recognition task. The semantic similarity value of each new concept was calculated as the mean cosine similarity between pairs of vectors representing that new concept and each old concept belonging to the same semantic category. Results showed that, compared with (new) low-similarity concepts, (new) high-similarity concepts had significantly higher probability of being falsely recognized as old, even after partialling out the effect of confounding variables, including associative relatedness and lexical co-occurrence. This finding supports the feature-based view of semantic memory, suggesting that meaning overlap and sharing of semantic features (which are greater when more similar semantic concepts are being processed) have an influence on recognition performance, resulting in more false alarms for new high-similarity concepts. We propose that the associative strength and word co-occurrence among concepts are not sufficient to explain illusory memories but is important to take into account also the effects of feature-based semantic relations, and, in particular, the semantic similarity among concepts.

False memory susceptibility is correlated with categorisation ability in humans.

Our memory is often surprisingly inaccurate, with errors ranging from misremembering minor details of events to generating illusory memories of entire episodes. The pervasiveness of such false memories generates a puzzle: in the face of selection pressure for accuracy of memory, how could such systematic failures have persisted over evolutionary time? It is possible that memory errors are an inevitable by-product of our adaptive memories and that semantic false memories are specifically connected to our ability to learn rules and concepts and to classify objects by category memberships. Here we test this possibility using a standard experimental false memory paradigm and inter-individual variation in verbal categorisation ability. Indeed it turns out that the error scores are significantly negatively correlated, with those individuals scoring fewer errors on the categorisation test being more susceptible to false memory intrusions in a free recall test. A similar trend, though not significant, was observed between individual categorisation ability and false memory susceptibility in a word recognition task. Our results therefore indicate that false memories, to some extent, might be a by-product of our ability to learn rules, categories and concepts.

Sedation and memories of patients subjected to mechanical ventilation in an intensive care unit.

Objective To investigate the relationship between sedation and the memories reported by patients subjected to mechanical ventilation following discharge from the intensive care unit. Methods This prospective, observational, cohort study was conducted with individuals subjected to mechanical ventilation who remained in the intensive care unit for more than 24 hours. Clinical statistics and sedation records were extracted from the participants' clinical records; the data relative to the participants' memories were collected using a specific validated instrument. Assessment was performed three months after discharge from the intensive care unit. Results A total of 128 individuals were assessed, most of whom (84.4%) reported recollections from their stay in the intensive care unit as predominantly a combination of real and illusory events. The participants subjected to sedation (67.2%) at deep levels (Richmond Agitation-Sedation Scale [RASS] -4 and -5) for more than two days and those with psychomotor agitation (33.6%) exhibited greater susceptibility to occurrence of illusory memories (p>0.001). Conclusion The probability of the occurrence of illusory memories was greater among the participants who were subjected to deep sedation. Sedation seems to be an additional factor that contributed to the occurrence of illusory memories in severely ill individuals subjected to mechanical ventilation.

Does Sleep Promote False Memories?

Memory is constructive in nature so that it may sometimes lead to the retrieval of distorted or illusory information. Sleep facilitates accurate declarative memory consolidation but might also promote such memory distortions. We examined the influence of sleep and lack of sleep on the cerebral correlates of accurate and false recollections using fMRI. After encoding lists of semantically related word associates, half of the participants were allowed to sleep, whereas the others were totally sleep deprived on the first postencoding night. During a subsequent retest fMRI session taking place 3 days later, participants made recognition memory judgments about the previously studied associates, critical theme words (which had not been previously presented during encoding), and new words unrelated to the studied items. Sleep, relative to sleep deprivation, enhanced accurate and false recollections. No significant difference was observed in brain responses to false or illusory recollection between sleep and sleep deprivation conditions. However, after sleep but not after sleep deprivation (exclusive masking), accurate and illusory recollections were both associated with responses in the hippocampus and retrosplenial cortex. The data suggest that sleep does not selectively enhance illusory memories but rather tends to promote systems-level consolidation in hippocampo-neocortical circuits of memories subsequently associated with both accurate and illusory recollections. We further observed that during encoding, hippocampal responses were selectively larger for items subsequently accurately retrieved than for material leading to illusory memories. The data indicate that the early organization of memory during encoding is a major factor influencing subsequent production of accurate or false memories.

From the archive: ‘Psychotherapy and memories of childhood sexual abuse: A cognitive perspective’ by D. S. Lindsay & J. D. Read (1994). Applied Cognitive Psychology, 8, 281–338 with commentary

AbstractCognitive psychological research on the fallibility of human memory is reviewed, focusing on evidence of memory distortions and illusions, with the aim of sharing research on memory with clinical psychologists and practitioners who use memory recovery techniques to help clients recover memories of suspected childhood sexual abuse. The authors' review of the memory literature suggested that incautious use of memory recovery techniques may lead some adult clients who were not abused to come to believe that they were. They consider current methods of assessing whether or not clients have repressed memories of childhood sexual abuse and techniques to minimise the risk of creating illusory memories or beliefs.

What can false memory tell us about memory impairments in Alzheimer’s disease?

The range of memory impairments associated with Alzheimer's disease (AD) has been a focus for psychological and clinical researchers for many years. In addition to investigations of AD patients’ veridical memory using traditional recognition memory tasks, a number of recent studies have focused on false memories to reveal the underlying causes of memory impairment in AD. Studies comparing illusory memories between AD patients and healthy older people have revealed various differences in memory deficits between the development of AD and the typical aging processes. Here, we review 3 types of memory illusions tested in AD patients: associative memory illusions, fluency-based false memories and source memory errors. By comparing AD patients with healthy older adults, we sought to analyze the mechanisms underlying AD-related memory impairments at different stages of memory processing, including encoding, retrieval and monitoring. This comparison revealed that AD patients exhibit an impaired ability to establish and utilize gist representations at the encoding stage and impairments in processing on the basis of familiarity and recollection at the retrieval stage. Consequently, patients with AD have access to less information when making memory judgments. As a result, they become more susceptible to the effects of item fluency, which can be manipulated during the retrieval stage. Furthermore, with impaired source memory monitoring abilities, the capacity of AD patients to suppress memory illusions is compromised. Based on these findings, we propose that the study of false memories constitute a critical tool for elucidating the memory impairments involved in AD. Further explorations of these memory impairments will have practical significance for the diagnosis and treatment of AD in the future.

Illusory Memories of Emotionally Charged Words in Autism Spectrum Disorder: Further Evidence for Atypical Emotion Processing Outside the Social Domain

Recent evidence suggests that individuals with ASD may not accumulate distinct representations of emotional information throughout development. On the basis of this observation we predicted that such individuals would not be any less likely to falsely remember emotionally significant as compared to neutral words when such illusory memories are induced by asking participants to study lists of words that are orthographically associated to these words. Our findings showed that typical participants are far less likely to experience illusory memories of emotionally charged as compared to neutral words. Individuals with ASD, on the other hand, did not exhibit this emotional modulation of false memories. We discuss this finding in relation to the role of emotional processing atypicalities in ASD.

Illusory recollection in older adults and younger adults under divided attention.

The authors investigated the effect of divided attention, study-list repetition, and age on recollection and familiarity. Older and younger adults under full attention and younger adults under divided attention at study viewed word lists highly associated with a single unstudied word (critical lure) once or three times, and subsequently performed a remember-know recognition test. Younger adults made fewer false remember responses to critical lures from repeated study lists, whereas younger adults under divided attention and older adults both showed an increase with repetition. Findings suggest older adults' susceptibility to illusory memories is related to a deficit in available attention during encoding.

Study effort versus distinctiveness in the recollection of veridical and illusory memories

In past research, stimulus distinctiveness and study effort have been claimed to promote the development of distinctive memories, which in turn have been considered critical for enhancing veridical recollection and reducing illusory memory experiences. In the present investigation, stimulus distinctiveness, obtained by displaying text-redundant pictorial information at study, was pitted against study effort to determine whether either factor would be more beneficial to veridical recall and more detrimental to illusory recall than the other. Subjects first completed word fragments with or without the aid of an image of each word's referent and then performed a recall test. It was found that when images were useful to the encoding task (fragment completion), their presence at study enhanced veridical recall and reduced illusory memories more than any additional encoding effort.

Trusting Our Memories: Dissociating the Neural Correlates of Confidence in Veridical versus Illusory Memories

Although memory confidence and accuracy tend to be positively correlated, people sometimes remember with high confidence events that never happened. How can confidence correlate with accuracy but apply also to illusory memories? One possible explanation is that high confidence in veridical versus illusory memories depends on different neural mechanisms. The present study investigated this possibility using functional magnetic resonance imaging and a modified version of the Deese-Roediger-McDermott false-memory paradigm. Participants read short lists of categorized words, and brain activity was measured while they performed a recognition test with confidence rating. The study yielded three main findings. First, compared with low-confidence responses, high-confidence responses were associated with medial temporal lobe (MTL) activity in the case of true recognition but with frontoparietal activity in the case of false recognition. Second, these regions showed significant confidence-by-veridicality interactions. Finally, only MTL regions showed greater activity for high-confidence true recognition than for high-confidence false recognition, and only frontoparietal regions showed greater activity for high-confidence false recognition than for high-confidence true recognition. These findings indicate that confidence in true recognition is mediated primarily by a recollection-related MTL mechanism, whereas confidence in false recognition reflects mainly a familiarity-related frontoparietal mechanism. This account is consistent with the fuzzy trace theory of false recognition. Correlation analyses revealed that MTL and frontoparietal regions play complementary roles during episodic retrieval. In sum, the present study shows that when one focuses exclusively on high-confidence responses, the neural correlates of true and false memory are clearly different.