Four pairs of connectionist simulations are presented in which quasi‐regular mappings are computed using localist and distributed representations. In each simulation, a control parameter termed input gain was modulated over the only level of representation that mapped inputs to outputs. Input gain caused both localist and distributed models to shift between regularity‐based and item‐based modes of processing. Performance on irregular items was selectively impaired in the regularity‐based modes, whereas performance on novel items was selectively impaired in the item‐based modes. Thus, (...) the models exhibited double dissociations without separable processing components. These results are discussed in the context of analogous dissociations found in language domains such as word reading and inflectional morphology. (shrink)

Dissociation during trauma lacks an adequate definition. Using data obtained from interviews with 36 posttraumatic individuals conducted according to the phenomenological approach, this paper seeks to improve our understanding of this phenomenon. In particular, it suggesting a trade off model depicting the balance between the sense of agency and the sense of ownership : a reciprocal relationship appears to exist between these two, and in order to enable control of the body during trauma the sense of ownership must decrease. When (...) the relationship between the sense of agency and sense of ownership changes disproportionately to the constraints of the traumatic event, the dissociative mechanism becomes dysfunctional. By contrast, when the relations alter in accordance with the surrounding conditions, the dissociative mechanism functions properly. (shrink)

One of the central problems of personal identity is to determine what we are essentially . In response to this problem, Lynne Rudder Baker espouses a psychological criterion, that is, she claims that persons are essentially psychological. Baker’s theory purports to bypass the problems of other psychological theories such as Dissociative Identity Disorder and the problem of individuating persons synchronically. I argue that the theory’s treatment of Dissociative Identity Disorder leads to untenable results, is invalid, and consequently fails to individuate (...) persons. (shrink)

Dissociative amnesia is a diagnosis category that implies a proposed mechanism (often called dissociation) by which amnesia is caused by psychogenic means, such as trauma, and that amnesia is reversible later. Dissociative amnesia is listed in some of the most influential diagnostic manuals. Authors have noted the similarities in definition to repressed memories. Dissociative amnesia is a disputed category and phenomenon, and here I discuss the plausibility that this cognitive mechanism evolved. I discuss some general conditions by which cognitive functions (...) will evolve, that is, the relatively continuous adaptive pressure by which a cognitive ability would clearly be adaptive if variation produced it. I discuss how adaptive gene mutations typically spread from one individual to the whole species. The article also discusses a few hypothetical scenarios and several types of trauma, to examine the likely adaptive benefits of blocking out memories of trauma, or not. I conclude that it is unlikely that dissociative amnesia evolved, and invite further development of these ideas and scenarios by others. (shrink)

This article discusses the possibility of practitioners who mistake organic memory loss for dissociative amnesia. It starts with the case of a young man with complete retrograde amnesia due to a traumatic head injury. Because he did not show any gross neurological abnormalities, a neurologist thought his amnesia had a psychological origin. An extensive neuropsychological examination revealed that the man did have an organic reason for his amnesia. Next, the existence of dissociative memory loss as well as isolated organic retrograde (...) amnesia is considered. While cases of organic memory loss are well-documented, there is hardly any evidence for dissociative amnesia. It is argued that organic memory loss might be mistakenly taken for dissociative amnesia. In line with the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders, practitioners are advised to rule out the possibility of organic memory loss, before diagnosing a patient with dissociative amnesia. (shrink)

_The Dissociative Mind in Psychoanalysis: Understanding and Working With Trauma_ is an invaluable and cutting edge resource providing the current theory, practice, and research on trauma and dissociation within psychoanalysis. _Elizabeth Howell and Sheldon Itzkowitz _bring together experts in the field of dissociation and psychoanalysis, providing a comprehensive and forward-looking overview of the current thinking on trauma and dissociation. The volume contains articles on the history of concepts of trauma and dissociation, the linkage of complex trauma and dissociative problems in (...) living, different modalities of treatment and theoretical approaches based on a new understanding of this linkage, as well as reviews of important new research. Overarching all of these is a clear explanation of how pathological dissociation is caused by trauma, and how this affects psychological organization -- concepts which have often been largely misunderstood._ _This book will be essential reading for psychoanalysts, psychoanalytically oriented psychotherapists, trauma therapists, and students. (shrink)

We review different analytic approaches to narratives by those with psychopathological conditions, and we suggest that the interpretation of such narratives are complicated by a variety of phenomenological and hermeneutical considerations. We summarize an empirical study of narrative distance in narratives by non-pathological subjects, and discuss how the results can be interpreted in two different ways with regard to the issue of dissociation.

This study tested the prediction that dissociative tendencies modulate the impact of a hypnotic induction on cognitive control in different subtypes of highly suggestible individuals. Low suggestible , low dissociative highly suggestible , and high dissociative highly suggestible participants completed the Stroop color-naming task in control and hypnosis conditions. The magnitude of conflict adaptation was used as a measure of cognitive control. LS and LDHS participants displayed marginally superior up-regulation of cognitive control following a hypnotic induction, whereas HDHS participants’ performance (...) declined. These findings indicate that dissociative tendencies modulate the influence of a hypnotic induction on cognitive control in high hypnotic suggestibility and suggest that HS individuals are comprised of distinct subtypes with dissimilar cognitive profiles. (shrink)

Neuropsychological dissociations between regular and irregular English past-tense morphology have been reported using a lexical decision task in which past-tense primes immediately precede present-tense targets. We present N400 event-related potential data from healthy participants using the same design. Both regular and irregular past-tense forms primed corresponding present-tense forms, but with a longer duration for irregular verbs. Phonological control conditions suggested that differences in formal overlap between prime and target contribute to, but do not account for, this difference, suggesting a (...) link between irregular morphology and semantics. Further analysis dividing the irregular verbs into two categories (weak irregular and strong) revealed that priming for strong verbs was reliably stronger than that for weak irregular and regular verbs, which were statistically indistinguishable from one another. We argue that, although we observe a regular-irregular dissociation, the nature of this dissociation is more consistent with single- than with dual-system models of inflectional morphology. (shrink)

The present study examined whether a dissociation among formats for rational numbers can be obtained in tasks that require comparing a number to a non-symbolic quantity. In Experiment 1, college students saw a discrete or else continuous image followed by a rational number, and had to decide which was numerically larger. In Experiment 2, participants saw the same displays but had to make a judgment about the type of ratio represented by the number. The magnitude task was performed more quickly (...) using decimals, whereas the relation task was performed more accurately with fractions. The pattern observed for percentages was very similar to that for decimals. A dissociation between magnitude comparison and relational processing with rational numbers can be obtained when a symbolic number must be compared to a non-symbolic display. (shrink)

Many theorists, in their search for a better explanation of the dynamics of structure and agency, have expressed the need for a theory in which reflexivity and habitus are reconciled. In this article, we argue that a dissociative theory of mind can provide the essential framework in which habitual routines and reflexivity function in parallel. This is explored using the examples of athletic training and hypnosis, where the interplay between conscious and unconscious mechanisms is displayed. In both settings, there is (...) evidence to show that conscious reflexiveness and intersubjective and unconscious automatic processes are necessary to reach the desired outcome. We conclude that a dissociative theory of mind can shed new light on the relationship between habitus and reflexivity. (shrink)

Dijkerman & de Haan (D&dH) argue that body image and body schema form parts of different and dissociable somatosensory streams. We agree in general, but believe that more emphasis should be placed on interactions between these two streams. We illustrate this point with evidence from the rubber-hand illusion (RHI) – an illusion of body image, which depends critically upon body schema.

It is a common assumption in contemporary cognitive neuroscience that discovering a putative realized kind to be dissociably realized (i.e., to be realized in each instance by two or more distinct realizers) mandates splitting that kind. Here I explore some limits on this inference using two deceptively similar examples: the dissociation of declarative and procedural memory and Ramachandran's argument that the self is an illusion.

Erdelyi does us all a great service by his customarily incisive discussion of the various ways in which our field tends to neglect, confuse, and misunderstand numerous critical issues in attempting to differentiate conscious from unconscious perception and memory. Although no single commentary could hope to comprehensively assess these issues, I will address Erdelyi’s three main points: How the dissociation paradigm can be used to validly infer unconscious perception; The implications of below-chance effects; and The role of time. I suggest (...) that significant progress on construct validity issues is possible; below-chance effects are part of a more general bidirectional phenomenon, very likely unconscious, and do not threaten absolute subliminality; and practice/learning effects pose potential difficulties for time-based dissociation paradigms. (shrink)

The existence or questionability of “repressed memories” can be discussed as being a matter of definition. It seems, however, far-fetched to consider all “lost” memories as caused by encoding problems, brain damage, forgetfulness, failure to disclose events, and so on. We argue that dissociative amnesia (DA) (or “psychogenic amnesia,” or “functional amnesia,” or, as we favor to call it, “mnestic block syndrome”) is caused by psychic alterations, but ultimately they can be traced to changes in the physiology of the brain, (...) as we are of the opinion that all memory processes—positive or negative—alter brain functions, sometimes more permanently, sometimes transiently. We have proven this idea using functional imaging techniques, in particular fluoro-deoxy-d-glucose positron emission tomography. Having investigated dozens of patients with severe and long-lasting DA conditions, we believe it to be disrespectful to many (but not to all) of the affected patients to question their disease condition, which can be proven to be not caused by feigning, malingering, or direct brain damage. (shrink)

The process-dissociation procedure was used to estimate the influence of spatial and form-based processing in the Simon task. Subjects made manual responses to the direction of arrows . The results provide evidence that the form and spatial location of a single stimulus can have functionally independent effects on performance. They also indicate the existence of two kinds of automaticity—an associative component that reflects prior S-R mappings and a nonassociative component that reflects the correspondence between stimulus and response codes.

In the valence contingency learning task (VCT), participants evaluate target words which are preceded by nonwords. Nonwords are predictive for positive/negative evaluations. Previous studies demonstrated that this results in (a) reliable contingency learning effects, reflected in better performance for highly contingent nonword-valence pairings and (b) less reliable evaluative conditioning (EC) effects, reflected in more positive ratings of nonwords that were highly predictive of positive (vs. negative) evaluative responses. In a highly-powered (N = 129) preregistered study, we investigated both effects and (...) assessed whether they are a consequence of episodic retrieval of incidental stimulus-response (SR) episodes and/or propositional learning (indicated by contingency awareness). Participants were either explicitly instructed about contingencies (instructed learning group) or not (incidental learning group). Both groups then worked through the VCT, an explicit rating task, and a contingency awareness test. Both groups showed contingency learning effects and EC effects for nonwords. Multi-level analyses showed that controlling for previous SR co-occurrences fully accounted for contingency learning effects in the incidental learning group. In the instructed learning group, a residual effect of genuine valence contingency learning remained. Nonword-specific contingency awareness in turn fully accounted for EC effects in both learning groups, indicating that genuine contingency learning effects reflect propositional learning. (shrink)

A key question for cognitive theories of reasoning is whether logical reasoning is inherently a sentential linguistic process or a process requiring spatial manipulation and search. We addressed this question in an event-related fMRI study of syllogistic reasoning, using sentences with and without semantic content. Our findings indicate involvement of two dissociable networks in deductive reasoning. During content-based reasoning a left hemisphere temporal system was recruited. By contrast, a formally identical reasoning task, which lacked semantic content, activated a parietal system. (...) The two systems share common components in bilateral basal ganglia nuclei, right cerebellum, bilateral fusiform gyri, and left prefrontal cortex. We conclude that syllogistic reasoning is implemented in two distinct systems whose engagement is primarily a function of the presence or absence of semantic content. Furthermore, when a logical argument results in a belief–logic conflict, the nature of the reasoning process is changed by recruitment of the right prefrontal cortex. (shrink)

This article reviews recent findings indicating some common brain processes during dissociative states and dreaming with the aim to outline a perspective that neural chaotic states during dreaming can be closely related to dissociative states that may manifest in dreams scenery. These data are in agreement with various clinical findings that dissociated states can be projected into the “dream scenery” in REM sleep periods and dreams may represent their specific interactions that may uncover unusual psychological potential of creativity in psychotherapy, (...) art and scientific discoveries. (shrink)

The paper makes three points about the role of double dissociation in cognitive neuropsychology. First, arguments from double dissociation to separate modules work by inference to the best, not the only possible, explanation. Second, in the development of computational cognitive neuropsychology, the contribution of connectionist cognitive science has been to broaden the range of potential explanations of double dissociation. As a result, the competition between explanations, and the characteristic features of the assessment of theories against the criteria of probability and (...) explanatory value, are more visible. Third, cognitive neuropsychology is a division of cognitive psychology but the practice of cognitive neuropsychology proceeds on assumptions that go beyond the subject matter of cognitive psychology. Given such assumptions, neuroscientific findings about lesion location may enhance the value of double dissociation in shifting the balance of support between cognitive theories. (shrink)

Dissociative style is mostly studied as a risk factor for dissociative pathology, but it may also reflect a fundamental characteristic of healthy information processing. Due to the close link between attention and working memory and the previous finding of enhanced attentional abilities with a high dissociative style, a positive relationship was also expected between dissociative style and verbal working memory span. In a sample of 119 psychology students, it was found that the verbal span of the high-dissociative group was about (...) half a word larger than of the medium and low-dissociative groups. It is suggested that dissociative style may be one of only very few individual differences that is directly relevant to consciousness research. (shrink)

Current thinking suggests that dissociation could be a significant comorbid diagnosis in a proportion of schizophrenic patients with a history of trauma. This potentially may explain the term “schizophrenia” in its original definition by Bleuler, as influenced by his clinical experience and personal view. Additionally, recent findings suggest a partial overlap between dissociative symptoms and the positive symptoms of schizophrenia, which could be explained by inhibitory deficits. In this context, the process of dissociation could serve as an important conceptual framework (...) for understanding schizophrenia, which is supported by current neuroimaging studies and research of corollary discharges. These data indicate that the original conception of “split mind” may be relevant in an updated context. Finally, recent data suggest that the phenomenal aspects of dissociation and conscious disintegration could be related to underlying disruptions of connectivity patterns and neural integration. (shrink)

In this article, I compare the epistemic standing of the function-to-structure inferences found in cognitive neuroscience and of the inferences based on dissociations in neuropsychology. I argue that the former have a poorer epistemic standing than the latter.

Müller argues that double dissociations do not imply underlying modularity of the cognitive system, citing neural networks as examples of fully distributed systems that can give rise to double dissociations. We challenge this claim, noting that suchdouble dissociations typically do not “scale-up,” and that even some singledissociations can be difficult to account for in a distributed system.

The objective of this study was to explore the participants’ processing strategies on the mere exposure effect, object decision priming and explicit recognition. In Experiments 1, we observed that recognition and the mere exposure effect for unfamiliar three-dimensional objects were not dissociated by plane rotations in the same way as recognition and object decision priming. However, we showed that, under identical conditions, prompting analytic processing at testing produced a large plane rotation effect on recognition and the mere exposure effect similar (...) to that observed for object decision priming. Furthermore, inducing a non-analytic processing strategy at testing produced a reduced plane rotation effect on recognition and object decision, similar to that observed for the mere exposure effect. These findings suggest that participants’ processing strategies influence performance on the three tasks. (shrink)

Religious practices centered on controlled trance states, such as Siberian shamanism or North African zar, are ubiquitous, yet their characteristics vary. In particular, cross-cultural research finds that female-dominated spirit possession cults are common in stratified societies, whereas male-dominated shamanism predominates in structurally flatter cultures. Here, we present an agent-based model that explores factors, including social stratification and psychological dissociation, that may partially account for this pattern. We posit that, in more stratified societies, female agents suffer from higher levels of psychosocial (...) trauma, whereas male agents are more vulnerable in flatter societies. In societies with fewer levels of formal hierarchy, males come into informal social competition more regularly than in stratified contexts. This instability leads to a cultural feedback effect in which dissociative experiences deriving from chronic psychosocial stress become canalized into a male religious trance role. The model reproduces these patterns under plausible parameter configurations. (shrink)

Dissociation and the Dynamics of Personality addresses the nature of personality in trauma-dissociation and proposes a dynamic understanding of persons that fundamentally challenges conventional views of the self and consciousness. This important book provides a clear and coherent understanding of how childhood trauma can lead to a range of dissociative responses, addressing the fundamental issues underlying the controversy in this field. By recognising causal complexity and the dynamic convergence of biology and culture, Boag demonstrates the significance of trauma-dissociation for understanding (...) personality and consciousness. Drawing upon both philosophy of mind and current psychiatric and neurobiological evidence, this book proposes a dynamic understanding of persons that fundamentally challenges the conventional view of the self and consciousness. Dissociation and the Dynamics of Personality will be of interest to readers concerned with the trauma-dissociation controversy, including philosophers of mind and psychiatrists. It will also interest psychological practitioners and psychologists, as well as anyone concerned with the implications of the dissociative mind for understanding personality. (shrink)

This article reports a study comparing the effects of a single dose of alcohol with a matched placebo drink on recognition memory with and without conscious recollection. A double-blind, cross-over design was used with healthy volunteers who were all social drinkers. Processing depth at study was manipulated using generate versus read instructions. Conscious recollection at test was assessed using the remember-know-guess paradigm (Gardiner, 1988; Tulving, 1985). Alcohol significantly reduced conscious recollection (remember responses) but had no effect on recognition in the (...) absence of conscious recollection (know responses). False alarms rates were low and unaffected by alcohol. Previous findings that generation effects are found only for remember responses were closely replicated. A further dissociation of the generation effect occurred between treatments in that deeper processing at study facilitated recognition on placebo but not on alcohol. That both alcohol and depth of processing produce dissociative effects on recollective experience provides further evidence that remembering and knowing reflect distinct memory systems. (shrink)

According to recent evidence, neurophysiological processes coupled to pain are closely related to the mechanisms of consciousness. This evidence is in accordance with findings that changes in states of consciousness during hypnosis or traumatic dissociation strongly affect conscious perception and experience of pain, and markedly influence brain functions. Past research indicates that painful experience may induce dissociated state and information about the experience may be stored or processed unconsciously. Reported findings suggest common neurophysiological mechanisms of pain and dissociation and point (...) to a hypothesis of dissociation as a defense mechanism against psychological and physical pain that substantially influences functions of consciousness. The hypothesis is also supported by findings that information can be represented in the mind/brain without the subject’s awareness. The findings of unconsciously present information suggest possible binding between conscious contents and self-functions that constitute self-representational dimensions of consciousness. The self-representation means that certain inner states of own body are interpreted as mental and somatic identity, while other bodily signals, currently not accessible to the dominant interpreter’s access are dissociated and may be defined as subliminal self-representations. In conclusion, the neurophysiological aspects of consciousness and its integrative role in the therapy of painful traumatic memories are discussed. (shrink)

Dissociative identity disorder is a dissociative disorder that gained a significant rise in the past few decades. There has been less than 50 DID cases recorded between 1922 and 1972, while 20,000 cases are recorded by 1990. Therefore, it becomes of great significant to assess the various concepts related to DID to further understand the disorder. The current review has a goal of understanding whether an individual suffering from DID is legally responsible for the committed crime, and whether or not (...) he or she can be considered competent to stand trial. These two questions are to be raised in understanding DID, by first shedding a light on the nature of the disorder and second by examining the past legal case examples. Despite the very nature of the disorder is characterized by dissociative amnesia and the fact that the host personality may have limited or no contact with the alters, there is no consensus within the legal system whether the DID patients should be responsible for their actions. Further to that, courts generally deny the insanity claims for DID suffering patients. In conclusion, more studies in the field are suggested to incorporate primary data into research, as the extensive reliance on secondary data forces us to believe the conclusions that were previously made, and no opportunity to verify those conclusions is present. (shrink)

Brain damage may doubly dissociate cognitive modules, but the practice of revealing dissociations is predicated on modularity being true (T. Shallice, 1988). This article questions the utility of assuming modularity, as it examines a paradigmatic double dissociation of reading modules. Reading modules illustrate two general problems. First, modularity fails to converge on a fixed set of exclusionary criteria that define pure cases. As a consequence, competing modular theories force perennial quests for purer cases, which simply perpetuates growth in the (...) list of exclusionary criteria. The first problem leads, in part, to the second problem. Modularity fails to converge on a fixed set of pure cases. The second failure perpetuates unending fractionation into more modules. (shrink)

The objective of this study was to explore the participants’ processing strategies on the mere exposure effect, object decision priming and explicit recognition. In Experiments 1, we observed that recognition and the mere exposure effect for unfamiliar three-dimensional objects were not dissociated by plane rotations in the same way as recognition and object decision priming. However, we showed that, under identical conditions, prompting analytic processing at testing produced a large plane rotation effect on recognition and the mere exposure effect similar (...) to that observed for object decision priming . Furthermore, inducing a non-analytic processing strategy at testing produced a reduced plane rotation effect on recognition and object decision , similar to that observed for the mere exposure effect. These findings suggest that participants’ processing strategies influence performance on the three tasks. (shrink)

How does violence shape citizens’ preferences for conflict termination? The existing literature has argued that violence either begets sympathy for more violence or drives support for making peace. Focusing on the 2016 Colombian Peace Agreement, this article finds that victimhood dissociation strongly shapes these preferences. With victimhood dissociation, a discrepancy exists between objective and subjective victimization, and the effect of violence on peace attitudes depends on citizens’ subjective interpretations of their personal experiences of violence. Citizens who do not experience violence (...) often see themselves as victims of the conflict and vice versa. Victimhood dissociation is linked to cultural stereotypes of victimhood as portrayed in elite narratives concerning the conflict. In Colombia, political leaders framed victimhood around rurality, business entrepreneurship, kidnapping, extortion, and disappearance. In 2016, this widespread narrative was instrumental for politicians opposing the peace agreement. Citizens who disassociated their personal experiences of violence from their self-understanding as victims were instrumental to the failure of the peace plebiscite. (shrink)

Llewellyn has written a fascinating article about rapid eye movement dreams and how they promote the elaborative encoding of recent memories. The main message of her article is that hyperassociative and fluid cognitive processes during REM dreaming facilitate consolidation. We consider one potential implication of this analysis: the possibility that excessive or out-of-phase REM sleep fuels dissociative symptomatology. Further research is warranted to explore the psychopathological ramifications of Llewellyn's theory.

Relational trauma can be understood as a psychological injury that occurs in the context of abusive interpersonal relationships and appears to be correlated with a wide array of mental illnesses. However, one potential harm of trauma that has not received much attention from philosophers is the threat it poses to authenticity. To understand why relational trauma potentially creates impediments to authentic agency, we need to consider two other phenomena that are commonly associated with it: (i) dissociation, and (ii) diminished habitual (...) trust. Whereas trauma-related dissociation commonly involves bodily alienation and detachment from the self, diminished habitual trust often leads to alienation from others. I maintain that dissociative detachment and diminished habitual trust often are mutually reinforcing and that, together, they can cause agents to become disconnected from themselves, others, and the reality of what has happened to them. What implications does this have for authentic agency among traumatized individuals? After outlining existing conceptions, I emphasize the important sense in which authenticity is relational and scaffolded by social connections. I also discuss several competencies that undergird authenticity and argue that the interplay between dissociative detachment and attenuated habitual trust can make it difficult for traumatized individuals to develop and sustain these competencies. Thus, the trauma they have experienced impedes their ability to conduct their lives in accordance with their genuine cares and desires. (shrink)

Two experiments are described that investigate the effects of attention in moderating evaluative conditioning (EC) effects in a picture‐picture paradigm in which previously discovered experimental artifacts (e.g., Field & Davey, 1999 Field, AP, and Davey, GCL, (1999). Reevaluating evaluative conditioning: A nonassociative explanation of conditioning effects in the visual evaluative conditioning paradigm, Journal of Experimental Psychology. Animal Behavior Processes 25 ((1999)), pp. 211–224.[Crossref], [PubMed], [Web of Science ®], [Google Scholar]) were overcome by counterbalancing conditioned stimuli (CSs) and unconditioned stimuli (USs) (...) across participants. Conditioned responses for individuals who had attention enhanced were compared against a control group and groups for whom attention was impeded using a distracter task. In a second experiment the effects of attention were dissociated from those of contingency awareness by using backward‐masked US presentations. The results of these experiments indicate that although associative EC effects may not be disrupted by a lack of contingency awareness, attention is an important factor in establishing conditioning. These results shed some light onto the possible boundary conditions that could explain past inconsistencies in obtaining EC effects in the visual paradigm. (shrink)

A definition of virtual or virtuality is not an easy task. Both words are of recent application in Philosophy, even if the concept of virtual comes from a respectable Latin tradition. Today’s meaning brings together the notions of potentiality, latency, imaginary representations, VR, and the forms of communication in digital media. This contagious, and spontaneous synonymy fails to identify a common vein and erases memory as a central notion. In the present essay, I’ll try to explain essential features of the (...) concept of virtual, taking the investigation of memory troubles in Pierre Janet’s work as an exemplification. Pierre Janet’s work represents a rare combination of medical observation and description of symptoms of mental illnesses, therapeutic guidance in hypnosis and philosophical writing about the main psychological themes of an epoch in transition from a Metaphysics of the Soul to the modern Experimental Psychology. Pierre Janet’s intellectual evolution since the 1880s until the end of his life is dominated by the philosophical project of a theory of the psychic system supported by three basic pillars: a concept of personality, a theory of memory and a sketch of a general theory of conduct. Such complex endeavour cannot be abstracted from the initial connections with Jean-Martin Charcot’s school at La Salpêtrière which meant a turning point in the tradition of the “animal magnetism” concerning the treatment of epileptic-hysterical symptoms along with the contributions of Hyppolite Bernheim’s “Nancy School” of hypnotism. J.-M. Charcot’s or H. Bernheim’s theorising about the organic and psychological aspects of the hypnotic treatment of the hysterical symptoms was already aware of the difficulty in dealing with the extent of the dissimulation of the patients regarding the symptoms of the illness, under hypnotic suggestion, even if Charcot insisted in the identification and cataloguing of the organic expressions, such as contractures or the posture of the body in arc during the attacks. The precise location of the “great hysteria” in the organic-psychic corridor was itself a riddle. If a symptom is a special type of sign, in the case of the “great hysteria” nobody knew for sure what it stood for. The clinical symptom of the attack stood for an organic trouble with cerebral causes, a psychological interruption of the normal sensorial and muscular movements or a disguise of the female desire? Pierre Janet described many hysterical patients, somnambulism and multiple personality since his articles in La Revue Philosophique de la France et l’ Étranger, a Journal founded by the philosopher, experimental psychologist and his intellectual predecessor Théodule-Armand Ribot. The description of the case of the “great hysterical” Lucie, treated by him, is an example of a theoretical hypothesising on multiple personality and discontinuity of memories fragments. There are more cases revealing the same relation between hysteria, somnambulism, personality dissociation and “alternating memory”. Decisively inspired by and corroborating P. Janet’s ideas, S. Freud conceived also the essential of the hysterical sicknesses as disorders of memory. The theme of memory came even more to the foreground in the dissertation L’Automatisme Psychologique. Here, the strange world of somnambulism was scrutinised along with hysterical contractures and convulsions, anaesthesia, the compulsion to repetition, obsessions, “automatic writing” in hysterical patients, multiple personality and “alternating memories”. In the depicted cases memory could not be taken as a homogenous series of remembrances or as a stock of disposable information but as a variable of the depth of the personalities’ inner formation. The so-called “seconde existence” of some somnambulists referred not only unconscious representations and unconscious thoughts but complete or inceptive latent personalities provided with multiple virtual existences and multiple memories. Hypnosis was the privileged technique to access to such multiple memories ignored by the official personality. Later and after the writing of his M.D. Dissertation, Contribution à l’ Étude des Accidents Mentaux chez les Hystériques, P. Janet addressed again the themes of memory and alternating memories in a series of lectures at the Collège de France but now according to the larger framework of a general theory of conduct which included a description of the social actions participating in the narrative construction of personal memories, and the role of social memory. (shrink)