Oh it's me again: Déjà vu, the brain, and self-awareness

Déjà vu and involuntary autobiographical memories (IAMs) are differentiated by a number of factors including metacognition. In contrast to IAMs, déjà vu activates regions associated with self-awareness including the right dorsolateral prefrontal cortex.

Déjà vu and involuntary autobiographical memories as two distinct cases of familiarity in patients with Alzheimer's disease

The continuum between involuntary autobiographical memories and déjà vu, as proposed by Barzykowski and Moulin, can be better defined by considering research on autobiographical retrieval in patients with Alzheimer's disease. Although autobiographical retrieval in patients with Alzheimer's disease can generally be associated with a sense of familiarity, involuntary retrieval can trigger an autonoetic experience of retrieval in these patients.

Distinguishing involuntary autobiographical memories and déjà vu experiences: Different types of cues and memory representations?

Although involuntary autobiographical memories (IAMs) and déjà vu have important shared characteristics, in this commentary, we focus on potential differences that may question the argument that two phenomena lie on a continuum. We propose that differences in their frequency and autonoetic consciousness could be explained by different types of cues and memory representations involved in experiencing IAMs and déjà vu.

Intracranial electrical brain stimulation as an approach to studying the (dis)continuum of memory experiential phenomena

Déjà vu and involuntary autobiographical memories (IAM) can be induced by intracranial electric brain stimulation in epileptic patients, sometimes in the same individual. We suggest that there may be different types of IAM which should be taken into account and provide several ideas to test the hypothesis of a continuity between IAM and déjà vu phenomena.

Evolutionary mismatch and anomalies in the memory system

In order to understand involuntary autobiographical memories and déjà vu experiences, we argue that it is important to take an evolutionary medicine perspective. Here, we propose that these memory anomalies can be understood as the outcomes of an inevitable design trade-off between type I and type II errors in memory processing.

The need for a unified framework: How Tulving's framework of memory systems, memory processes, and the SPI-model can guide and sharpen the understanding of déjà vu and involuntary autobiographical memories and add to conceptual clarity

Barzykowski and Moulin link déjà vu and involuntary autobiographical memories to the process of retrieval. They make no reference to Tulving's SPI-model. In this, it is proposed that information is acquired serially (S), stored in parallel (P), and retrieved independently (I). This model offers an alternative, elegant, view of involuntary autobiographical memory retrieval, as well as of déjà vus.

On the frequency and nature of the cues that elicit déjà vu and involuntary autobiographical memories

Barzykowski and Moulin suggest that déjà vu and involuntary autobiographical memories recruit similar retrieval processes. Here, we invite the authors to clarify three issues: (1) What mechanism prevents déjà vu to happen more frequently? (2) What is the role of semantic cues in involuntary autobiographical retrieval? and (3) How déjà vu relates to non-believed memories?

Does inhibitory (dys)function account for involuntary autobiographical memory and déjà vu experience?

External cues and internal configuration states are the likely instigators of involuntary autobiographical memories (IAMs) and déjà vu experience. Indeed, Barzykowski and Moulin discuss relevant neuroscientific evidence in this direction. A complementary line of enquiry and evidence is the study of inhibition and its role in memory retrieval, and particularly how its (dys)function may contribute to IAMs and déjà vu.

A spontaneous neural replay account for involuntary autobiographical memories and déjà vu experiences

Barzykowski and Moulin argue both involuntary autobiographical memories and déjà vu experiences rely on the same involuntary memory retrieval processes but their underlying neurological basis remains unclear. We propose spontaneous neural replay in the default mode network (DMN) and hippocampus as the basis for involuntary autobiographical memories, whereas for déjà vu experiences such transient activation is limited to the DMN.

What do we gain (or lose) by considering déjà vu a part of autobiographical memory?

I argue the relationship between déjà vu and autobiographical memory is not continuous, but more akin to a path diagram. The starting points might be overlapping, but eventually the paths diverge dependent on whether there is memory content to be retrieved. I am worried that considering déjà vu as part of autobiographical memory solves more problems than it creates.

Are involuntary autobiographical memory and déjà vu natural products of memory retrieval?

Involuntary autobiographical memories (IAMs) and déjà vu are phenomena that occur spontaneously in daily life. IAMs are recollections of the personal past, whereas déjà vu is defined as an experience in which the person feels familiarity at the same time as knowing that the familiarity is false. We present and discuss the idea that both IAMs and déjà vu can be explained as natural phenomena resulting from memory processing and, importantly, are both based on the same memory retrieval processes. Briefly, we hypothesise that both can be described as "involuntary" or spontaneous cognitions, where IAMs deliver content and déjà vu delivers only the feeling of retrieval. We map out the similarities and differences between the two, making a theoretical and neuroscientific account for their integration into models of memory retrieval and how the autobiographical memory literature can explain these quirks of daily life and unusual but meaningful phenomena. We explain the emergence of the déjà vu phenomenon by relating it to well-known mechanisms of autobiographical memory retrieval, concluding that IAMs and déjà vu lie on a continuum.

Editorial Commentary: Déjà Vu: Double-Bundle Anterior Cruciate Ligament Reconstruction Revisited

Regardless of the technique utilized, tunnel expansion following anterior cruciate ligament reconstruction remains a mystery and a clinical challenge. No procedure seems to be immune to this, even anatomic double-bundle reconstruction. This technique was introduced more than 20 years ago and showed great promise while also contributing significantly to our current knowledge of anterior cruciate ligament anatomy and biomechanics. However, we must remember that new techniques do carry with them new side effects that we must document and acknowledge if we hope to improve our surgical outcomes.

[A case series of 4 epilepsy patients with promnesia]

Promnesia is a feeling of familiarity and foreknowledge and is a manifestation of simple partial seizures (focal aware seizures). It is similar to déjà vu and has been reported to be a rare symptom in patients with temporal lobe epilepsy. Here, we investigated the clinical characteristics in 4 patients with partial epilepsy presenting promnesia. Three out of 4 patients showed abnormal electroencephalography (EEG) and/or MRI findings in the temporal lobe. Furthermore, in 2 patients, promnesia was the only aura. It is important to actively obtain medical history of patients about promnesia because this is useful for identifying the epileptic focus. Further cases need to be analyzed to evaluate the sensitivity and specificity of promnesia for diagnosis and therapy of partial epilepsy.

Representations of epilepsy on the stage: From the Greeks to the 20th century

Epilepsy is a disorder that has been used by dramatists in various ways over the ages and therefore highlights the views of the disorder as people saw it at the time the plays were written and performed. In the 6th century BC, links between tragedy and epilepsy were developed by Greek playwrights, especially Euripides, in Iphigenia among the Taureans and Heracles where epilepsy and madness associated with extreme violence occur together. Both Heracles and Orestes have episodes after a long period of physical exhaustion and nutritional deprivation. During the Renaissance, Shakespeare wrote plays featuring different neurological disorders, including epilepsy. Epilepsy plays a crucial part in the stories of Julius Caesar and Othello. Julius Caesar is a play about politics, and Caesar's epilepsy is used to illustrate his weakness and vulnerability which stigmatizes him and leads to his assassination. Othello is a play about jealousy, and Othello, an outsider, is stigmatized by his color, his weakness, and his 'seizures' as a form of demonic possession. In modern times, Night Mother portrays the hard life of Jessie, who lives with her mother. Jessie has no friends, her father has abandoned the family, and she has no privacy and is ashamed. Stigma and social pressures lead her to commit suicide. Henry James' novella, The Turn of the Screw, portrays a governess with dream-like states, déjà vu, and loss of temporal awareness who has been sent to the country to look after two small children and ends up killing one. This novella was turned into an opera by Benjamin Britten. Most recently, performance art has been portraying epilepsy as the reality of a personally provoked seizure. Both Allan Sutherland and Rita Marcalo have purposely provoked themselves to have a seizure in front of an audience. They do this to show that seizures are just one disability. Whether this provokes stigma in audiences is unknown. Whether the performance artists understand the potential for status epilepticus has not been discussed. This article is part of a Special Issue entitled "Epilepsy, Art, and Creativity".

Policies to protect persons with dementia in assisted living: déjà vu all over again?

Continued growth in the number of individuals with dementia residing in assisted living (AL) raises concerns about their safety and protection. In this Forum, we review current AL practices relevant to residents with dementia and present a rationale for examining the government role in protecting these individuals within this context. Since public oversight of AL is currently a state prerogative, we assess states' regulatory activity across 3 domains closely related to safety and protection of persons with dementia: environmental features, staffing, and use of chemical restraints. We then step back to consider the state policymaking environment and assess the feasibility of developing a minimum standard of regulations from one state to the next. This Forum concludes with a historical comparison between the contemporary AL market and the nursing home care market prior to the Nursing Home Reform Act of 1987, and we discuss how an increased amount of federal interest could improve existing state efforts to protect persons with dementia residing in AL.

Dissociating recollection from familiarity: Electrophysiological evidence that familiarity for faces is associated with a posterior old/new effect

In recognition memory research, a tension exists between dual-process and single-process models of episodic retrieval. Dual-process models propose that 'familiarity' assessment and the 'recollection' of contextual information are independent processes, while single-process models claim that one common process supports retrieval. Event-related potentials (ERPs) have been used to show dissociations between the mid frontal and the left parietal ERP old/new effects, which have been associated with familiarity and recollection, respectively. While much ERP evidence favours dual-process theory, Yovel and Paller [Yovel, G., Paller, K.A., 2004. The neural basis of the butcher-on-the-bus phenomenon: when a face seems familiar but is not remembered. NeuroImage 21, 789-800] used faces as retrieval cues to demonstrate that posterior old/new effects index both familiarity and recollection, a finding consistent with single-process models. Here we present evidence supporting Yovel and Paller's claim that a posterior old/new effect indexes familiarity for faces, along with a novel finding that recollection is associated with an anterior old/new effect. Importantly, and in contrast to Yovel and Paller, the old/new effects associated with familiarity and recollection were topographically dissociable, consistent with a dual-process view of recognition memory. The neural correlates of familiarity and recollection identified here for faces appear to be different from those typically observed, suggesting that the ERP old/new effects associated with episodic recognition are not the same under all circumstances.

The FN400 indexes familiarity-based recognition of faces

Separate event-related brain potential (ERP) components have been hypothesized to index familiarity and recollection processes that support recognition memory. A 300- to 500-ms mid-frontal FN400 old/new difference has been related to familiarity, whereas a 500- to 800-ms parietal old/new difference has been related to recollection. Other recent work has cast doubt on the FN400 familiarity hypothesis, especially its application to familiarity-based recognition of conceptually impoverished stimuli such as novel faces. Here we show that FN400 old/new differences can be observed with novel faces, and as predicted by the familiarity hypothesis, these differences are observed regardless of whether or not recognition is accompanied by the recollection of specific details from the study episode. Furthermore, FN400 differentiation between hits and misses is more consistent with an explicit familiarity process than an implicit memory process.

From the Atom to the Cell: Is the Cat Alive? Quantum Mechanics and Stem Cell Plasticity as Déjà Vu

The concepts submitted by quantum mechanics fascinated the scientific community during the first half of the 20(th) century. The second half was dominated by biology, culminating in the sequencing of the human genome and the study of stem cells. Although the anticipated revolution of cellular therapies in medicine is in its infancy, the conceptual debate over stem cell plasticity shares similarities with evolution of the quantum theory. Are there notions and modes of thinking that stem cell biologists should adopt from the evolution in the interpretation of the laws of physics?

Exploring the recognition memory deficit in Parkinson's disease: estimates of recollection versus familiarity

Current theories postulate that recognition memory can be supported by two independent processes: recollection (i.e. vivid memory for an item and the contextual details surrounding it) versus familiarity (i.e. the mere sense that an item is old). There is conflicting evidence on whether recognition memory is impaired in Parkinson's disease, perhaps because few studies have separated recollection from familiarity. We aimed to explore whether recollection or familiarity is more likely to be affected by Parkinson's disease, using three methods: (i) the word-frequency mirror effect to make inferences about recollection and familiarity based on recognition of high- versus low-frequency words, (ii) subjective estimates of recollection (remembering) versus familiarity (knowing), and (iii) a process-dissociation procedure where participants are required to endorse only some of the previously studied items on a recognition memory test, but not others. We tested Parkinson's disease patients (n = 19 and n = 16, age range = 58-77 years and age range = 50-75 in Experiments 1 and 2, respectively) and age- and education-matched controls (n = 23 and n = 16 in Experiments 1 and 2, respectively). Overall, the Parkinson's disease group showed a reduction in recognition memory, but this appeared to be primarily due to impairment of familiarity, with a lesser decline in recollection. We discuss how this pattern may be related to dysfunction of striatal, prefrontal and/or medial temporal regions in Parkinson's disease.

Cortical stimulation study of the role of rhinal cortex in déjà vu and reminiscence of memories

OBJECTIVE

To study the role of perirhinal (PC) and entorhinal cortices (EC) in dreamy state symptoms (déjà vu and reminiscence of scenes). These phenomena have been attributed to functional alteration of memory networks supported by the medial temporal lobes, principally involving the amygdala and hippocampus. The role of sub-hippocampal structures (EC and PC) in inducing these phenomena has not previously been addressed.

METHODS

The authors studied the symptoms evoked by direct electrical stimulations of PC and EC in comparison with those obtained after stimulation of the amygdala and hippocampus. Stimulations were performed in a group of 24 patients with epilepsy, during stereoelectroencephalographic (SEEG) recordings in the setting of presurgical evaluation. All patients had electrodes that sampled the rhinal cortices, amygdala, and hippocampus.

RESULTS

A total of 280 stimulations were analyzed. Entorhinal and perirhinal stimulations induced classic mesial temporal lobe responses (emotional, dysautonomic) but also more specific responses, particularly the déjà vu phenomenon and reminiscence of scenes. Such déjà vu or déjà vécu type responses were produced proportionately more often by stimulation of the EC than by stimulation of the amygdala and hippocampus. In particular, déjà vu was associated with stimulation of the EC and reminiscence of memories with PC stimulation.

CONCLUSION

This study strongly suggests that experiential symptoms are largely dependent upon functional modification of the physiology of the rhinal cortices.

Disordered memory awareness: recollective confabulation in two cases of persistent déjà vecu

We describe two cases of false recognition in patients with dementia and diffuse temporal lobe pathology who report their memory difficulty as being one of persistent déjà vecu--the sensation that they have lived through the present moment before. On a number of recognition tasks, the patients were found to have high levels of false positives. They also made a large number of guess responses but otherwise appeared metacognitively intact. Informal reports suggested that the episodes of déjà vecu were characterised by sensations similar to those present when the past is recollectively experienced in normal remembering. Two further experiments found that both patients had high levels of recollective experience for items they falsely recognized. Most strikingly, they were likely to recollectively experience incorrectly recognised low frequency words, suggesting that their false recognition was not driven by familiarity processes or vague sensations of having encountered events and stimuli before. Importantly, both patients made reasonable justifications for their false recognitions both in the experiments and in their everyday lives and these we term 'recollective confabulation'. Thus, the patients are characterised by false recognition, overextended recollective experience, and recollective confabulation. These features are accounted for in terms of disrupted control of memory awareness and recollective states, possibly following brain damage to fronto-temporal circuits and we extend this account to normally and abnormally occurring states of déjà vu and vecu and related memory experiences.

A review of the déjà vu experience

For more than a century, the déjà vu experience has been examined through retrospective surveys, prospective surveys, and case studies. About 60% of the population has experienced déjà vu, and its frequency decreases with age. Déjà vu appears to be associated with stress and fatigue, and it shows a positive relationship with socioeconomic level and education. Scientific explanations of déjà vu fall into 4 categories: dual processing (2 cognitive processes momentarily out of synchrony), neurological (seizure, disruption in neuronal transmission), memory (implicit familiarity of unrecognized stimuli),and attentional (unattended perception followed by attended perception). Systematic research is needed on the prevalence and etiology of this culturally familiar cognitive experience, and several laboratory models may help clarify this illusion of recognition.

Feeling-of-knowing in episodic memory: an event-related fMRI study

An individual may fail to recall an item from memory but still feel that it would be recognized on a later test, a retrieval state termed the "feeling-of-knowing" (FOK). In this study we used event-related fMRI and the FOK to examine both encoding- and retrieval-related factors that are associated with different levels of recall performance: successful retrieval of a previously studied item, retrieval failure accompanied by the FOK, and retrieval failure without any FOK. The results revealed one predominant pattern of retrieval-related activation: an intermediate level of activation for FOK-less than that associated with successful recall and greater than that associated with unsuccessful recall (frontal and left parietal cortices). Two further patterns were also observed: greater activation for both successful recall and FOK than for unsuccessful recall (left midlateral prefrontal cortex) and greater activation for successful recall than for both FOK and unsuccessful recall (left MTL). Analysis of encoding trials conditional upon subsequent retrieval success revealed a pattern of activation that appeared to predict subsequent recall, but which further analysis indicated to be a better predictor of subsequent recognition. These results provide evidence that the phenomenology of graded recall is represented neurally in frontal and parietal cortices, but that activation at encoding may not precipitate the different levels of recall experience.

Paramnesic multiplication of autobiographical memory as a manifestation of interictal psychosis

This report describes a male patient with temporal lobe epilepsy who developed a persistent paranoid-hallucinatory state at the age of 23. The essential feature of his delusion was that he had repeatedly lived part of his life, namely between the ages of 21 and 25 years. The patient repeatedly attempted suicide to escape the endless repetition. His paramnesia has some similarity with a déjà vu phenomenon, which is a common ictal manifestation of temporal lobe epilepsy. However, while only a sense of vague familiarity is evoked in a déjà vu phenomenon, conscious recollection is experienced during his paramnesia. We attempted to explain the pathophysiological mechanism of the patient's paramnesia in the framework of the current neurobiological theory of human memory.

Intense and recurrent déjà vu experiences related to amantadine and phenylpropanolamine in a healthy male

We report a case of a 39-year-old caucasian healthy male physician who developed intense and recurrent déjà vu experiences within 24h of initiating concomitant amantadine-phenylpropanolamine treatment against influenza. Déjà vu experiences terminated on discontinuation of medication. Findings in temporal epilepsy suggest that mesial temporal structures, including hippocampus, are related to paramnesic symptoms. On the other hand, previous case reports have confirmed that both amantadine and phenylpropanolamine alone, and particularly in combination, can induce psychotic symptoms due to their dopaminergic activity. The authors suggest that déjà vu experiences may be provoked by increased dopamine activity in mesial temporal structures of the brain.

Absence of simple partial seizure in temporal lobe epilepsy: its diagnostic and prognostic significance

The diagnostic and prognostic significance of the absence of simple partial seizures (SPS) immediately preceding complex partial seizures (CPS) was examined in patients with temporal lobe epilepsy. The status of self-reported SPS in 193 patients with temporal lobe epilepsy who had surgical therapy more than 2 years ago was reviewed. Before surgery, 37 patients never experienced SPS before CPS (Group A), 156 patients either always or occasionally had SPS before CPS (Group B). The frequency of mesial temporal sclerosis (MTS) was lower and the age at onset of epilepsy was higher in Group A. The seizure focus was in the language-dominant temporal lobe in 73% of the cases in Group A, compared with 40% in Group B. The surgical outcome did not differ between the two groups. The findings suggest that temporal lobe seizures without preceding SPS tend to originate in the language-dominant temporal lobe that contains a pathologic etiology other than MTS, especially in the lateral temporal lobe. The surgical outcome in patients without SPS is similar to that in patients with SPS.

Familial temporal lobe epilepsy autosomal dominant inheritance in a large pedigree from southern Italy

To further elucidate the inheritance pattern and range of phenotypic manifestations of benign familial temporal lobe epilepsy (FTLE), we report a large family recently identified in southern Italy. There were 8 patients (4 men), ranging in age from 31 to 68 years in three generations. One affected patient was deceased at the time of the study. Genealogical study strongly supported autosomal dominant inheritance with incomplete penetrance, as three unaffected individuals transmitted the disease. Clinical anticipation could not be assessed because of the ascertainment method. Male to male transmission occurred. Identifiable antecedents for seizures were present in only two patients, who had a simple febrile convulsion and a closed head trauma, respectively. Migraine was overrepresented in this family. Onset of seizures ranged from 17 to 52 years (mean: 27 years). All patients had weekly simple partial seizures suggestive of temporal origin with vegetative or experiential phenomena. Very rare partial complex seizures occurred in 6/7 patients. One had two generalized nocturnal seizures as well. Two had previously been misdiagnosed as having gastritis or panic attacks, and one had not been diagnosed. Interictal anteromesiotemporal spiking was seen in 5/7 patients, and occurred mostly during NREM sleep. Neurological examination, brain CT or MR scans were normal. Antiepileptic medication always controlled the seizures.

Modeling precognitive dreams as meaningful coincidences

50 college students completed the Anomalous Experiences Inventory, the AT-20 measure of tolerance of ambiguity, and a frequency of dream recall questionnaire. Using path analysis we show that precognitive dreams can be modeled as accidental 'hits' with increased dream recall and the interpretation of such hits as 'meaningful coincidences' seems facilitated by a belief in the paranormal. As predicted, both factors are affected by tolerance of ambiguity, which provides the flexibility required to store and recall ambiguous dream information while simultaneously allowing dream recallers to assume a paranormal origin of their 'precognitive' dreams. Moreover, the fit of the proposed model did not depend on sex or age. Alternative models that provided a better fit to the data validated the roles of tolerance of ambiguity and belief in the paranormal in eliciting experiences of precognitive dreaming, but frequency of dream recall was not confirmed as a crucial factor.

Reengineering: deja vu all over again

There is growing interest among hospitals in reengineering. It promises dramatic improvements in performance: Costs will be reduced while work processes, productivity, and patient care will all improve. A review of the health care literature on reengineering shows that little evidence exists to support its claims. This article critiques the existing literature on reengineering and addresses the conundrum hospital executives encounter when faced with the decision to adopt a new management technique--such as reengineering--in the absence of proof of its efficacy.

[Diagnosis of seizures originating in the amygdala and the hippocampus]

INTRODUCTION

Lesions in the hippocampus of some epileptic patients were first described one hundred and seventy years ago. Since then our knowledge of the relationship between epileptic seizures and temporal lobe lesions has greatly improved.

DEVELOPMENT

The aim of this paper is to systematize the symptomatology of the hippocampus and amygdala seizures. These seizures may have a great number of different clinical features: special 'loss' or 'impairment of consciousness', epileptic automatisms and autonomic changes. Moreover, at the beginning of seizures some patients have reported experiences having subjective qualities similar to those experienced in everyday life. P Gloor named them 'experiential phenomena' and subdivided them into affective (eg: fear), perceptual (eg: visual hallucinations) and mnemonic (eg: 'déjà vu' illusion).

CONCLUSION

It is very important to know the contribution of the hippocampus and the amygdala to the symptomatology of temporal lobe seizures due to the progress of MRI diagnostic possibilities that are improving the surgical outcome.

Screen reconstructions: traumatic memory, conviction, and the problem of verification

Just as formerly recalled screen memories may be remembered again in the course of psychoanalysis, so new screen phenomena can arise during the treatment process. This paper attempts to relate the process of reconstruction and the occurrence of a type of screening. It is proposed that, under certain circumstances, psychoanalysis can result in a mutually determined screen construction that both patient and analyst consider convincing and valid but which may, for the most part, actually be untrue as a result of the screen function. Screen memories arising during the reconstructive process resemble the déjà vu and déjà raconté situation in that the experience is felt with certainty to have actually occurred previously, although a degree of doubt about its having happened can consciously or unconsciously coincide. Factors contributing to the formation of screen constructions include regressive aspects of the analytic situation; superego elements and the experience of an injunction to remember; the wish to witness what took place in the past; direct or indirect suggestive influence by the analyst; a defensive identification with the analyst; and the analyst's theoretical orientation to reconstruction. Like a screen memory having some veridical content yet serving a masking function, a screen construction can have elements of truth. At the same time such constructions may function as a strong resistance of compromise against intense erotic, sadomasochistic, or narcissistic themes in the transference/counter-transference that were painful or conflictual in the past. If screen constructions are assumed to be historically real or valid, they may not be analyzed for their transferential screening role. A previously published case involving a presumably repressed memory of sexual molestation is considered from the perspective of the possible development of a screen reconstruction. Clinical and scientific aspects of seeking extra-analytic confirmation or falsification of reconstructions are discussed.

Role of memory strength in reality monitoring decisions: evidence from source attribution biases

Reality monitoring of verbal memories was compared with decisions about pictorial memories in this study. Experiment 1 showed an advantage in memory for imagined over perceived words and a bias to respond "perceived" on false alarms. Experiment 2 showed the opposite pattern: an advantage in memory for perceived pictures and a bias to respond "imagined" on false alarms. Participants attribute false alarms to whichever class of memories has the weakest trace strengths. The relative strength of memories of imagined and perceived objects was manipulated in Experiments 3 and 4, yielding changes in source attribution biases that were predicted by the strength heuristic. All 4 experiments generalize the mirror effect (an inverse relationship between patterns of hits and false alarms commonly found on recognition tests) to reality monitoring decisions. Results suggest that under some conditions differences between the strength of memories for perceived and imagined events, rather than differences in qualitative characteristics, are used to infer memory source.

Déjà vu in France during the 19th century: a conceptual history

The feeling of déjà vu features as prominently in the creative as in the clinical literature. However, its meaning and mechanisms remain unclear, and it is posited here that this has partially resulted from the way in which this symptom was originally conceptualized. During the late 19th century, medical opinion seemed agreed that déjà vu was a disorder of memory (a paramnesia). However, its study was obfuscated by an overemphasis on its secondary features (e.g., "feeling of conviction," "fleetingness") and by "parapsychological" interpretations. Around the turn of the century, the problem was compounded by the development of narrow models of memory (inspired by association psychology) that left no room for the descriptive complexities of déjà vu. Consequently, it soon became (and has remained) a "symptom without a psychological function." French psychological writers played a crucial role in the conceptualization of déjà vu and this report presents a detailed history of their contribution.

Memory distortion and sexual trauma: the problem of false negatives and false positives

Logically, two broad types of mnemonic errors are possible when adult psychotherapy or hypnosis patients reflect on whether they were sexually abused or not as a child. They may believe that they were not abused when in fact they were (false negative error), or they may believe they were abused when in fact they were not (false positive error). The author briefly reviews the empirical evidence for the occurrence of each of these types of errors, and illustrates each with a clinical case. Further, in considering the incidence, importance, and clinical implications of these errors, the author contends that clinical efficacy in no way assures that a false negative or a false positive has been avoided. A plea is made for theorists and researchers to acknowledge that both categories of errors can occur and to conduct future clinical and laboratory research accordingly.

The concept of flashbacks in historical perspective

A computer search of the literature for papers indexed under "flashbacks" produced a list of 70 references, many found in publications on the topics of substance abuse and trauma. Several of these were letters or papers written in languages other than English. In all, the author reviewed 55 papers. Although most of these papers contained comments that addressed the subject matter to some extent as recurrences or reminiscences of past happenings, the variability in the use of the term leaves many unresolved questions regarding the veridicality of the imagery. Nothing in the presentations reviewed by the author clearly demonstrates the unidimensional nature of flashbacks nor any recognizable neurophysiological correlate. The content of a flashback appears to be at least as likely to be the product of imagination as it is of memory.