Approches clinique, cognitive et physiopathologique de l'Ictus Amnésique idiopathique

CAEN-BU Droit Lettres (141182101) / SudocSudocFranceF

Qu'est-ce que la mémoire de l'action ? Revue théorique et perspectives

International audienceThis paper presents a summary of memory for action researches, in normal functioning and neurological pathologies. Memory for action is a distinct form of episodic memory, especially important in everyday life although current literature is not very abundant. The enactment effect (i.e. better memory for performed actions than for verbally encoded sentences) is usually described as a robust effect in aging and can be found in many diseases. Although the enactment effect has been studied for three decades, there is still no consensus on how it enhances memory. Different theories postulate the motor component is crucial, the importance of binding or goal-oriented actions. Memory for action also gives information concerning source memory and sense of agency (i.e. subjective awareness that one is controlling his own movement). Moreover, numerous studies showed the importance of enactment effect in children and adults’ new learning, and an opportunity to use this effect in patients’ rehabilitation, including amnesic ones. Characteristics of memory for actions and mechanisms underlying enactment effect still remain unclear and other researches need to be performed.Cet article propose une synthèse des différentes recherches menées sur la mémoire de l'action dans le cadre du fonctionnement normal et de la pathologie. La mémoire de l'action est une forme spécifique de mémoire épisodique, particulièrement importante dans la vie quotidienne mais néanmoins peu étudiée. Le bénéfice de l'action sur la mémoire est appréhendé au travers de l'effet de réalisation de l'action. Celui-ci se traduit parun meilleur rappel des actions effectivement réalisées comparativement à celles uniquement lues. Cet effet est robuste au cours du vieillissement et peut être retrouvé dans de nombreuses pathologies. Toutefois, i

La singularité du voyage mental dans le temps dans le trouble de stress post-traumatique

International audienc

La projection vers le futur : neuropsychologie, neuro-imagerie et psychopathologie

Although memory is thought to be past-oriented, it is also profoundly future-oriented, allowing both re-experiencing of past life events and pre-experiencing of future events. This tendency to project into the future implies, as does episodic memory, a sufficient degree of self-awareness, an awareness that subsequently allows for a sense of continuity and individual identity in the long term. Therefore, future self-projection, also called “episodic future thinking”, constitutes an ability that is favorable to individual development, both in the adaptive capacities that it allows and in the individual future objectives that it creates in the long term. This continuity over time is assumed to be stable, regardless of the environmental, developmental, and social changes that occur around the subject throughout life. Moreover, future projection corresponds to a deeply introspective activity, as it is focused on internal processes and thoughts centered on past and future oneself. Numerous studies have shown that future projection involves the use of a particular neural network corresponding to the “default network”, i.e., a set of cerebral structures activated when the brain is at passive rest. A rest that is perhaps not a rest at all, since this time could be devoted to mental activities of introspection, notably within the framework of future simulations in relation to oneself and one's past. The episodic basis of future projection as well as the involvement of this default network makes it sensitive to any alteration of memory or psychological functioning, the impossibility of memorizing or recalling past events having a strong impact on the capacity to imagine the future. Examples include Alzheimer's disease, where hippocampal and therefore memory damage is associated with a strong alteration in the ability to estimate the remaining future time, or post-traumatic stress disorder, where traumatic exposure and the resulting symptoms lead to a feeling of a “foreshortened” future. This work proposes to revisit this demonstrated link between episodic memory and future projection, through the observation of a simultaneous impairment of mnesic and projective capacities, firstly in the field of clinical neuropsychology, secondly in the context of psychiatric and neurological pathologies. Beyond its episodic characteristic, recent literature now demonstrates the fundamentally identity-based foundation of future projection. Imagining and projecting oneself into the future would allow one to build a stable long-term individual identity, marked by the creation of healthy future goals appropriate to one's past and future life history. Moreover, it has been demonstrated today that the ability to project into the future has a real influence on the therapeutic work carried out in various psychiatric pathologies, such as addictive behaviors or post-traumatic stress disorder. We propose to return to this identity segment of future projection at greater length, a literature borrowing both from its episodic and phenomenological characteristics. Finally, we consider the development of a recent literature demonstrating a possible “double-edged” effect of future projection: behind the individual and identity fulfillment promoted by future projection may lie significant future anxiety, resulting from pervasive and maladaptive projection. It is possible that future projection requires a balancing effect, whose individual benefits and risks depend strongly on the associated identity and psychological context.Bien qu’on l’imagine tournée vers le passé, la mémoire s’avère également profondément tournée vers le futur, en permettant à la fois de ré-expérimenter les événements de vie passée et de pré-expérimenter les événements à venir. La projection de soi dans le futur, également appelée « pensée épisodique future », constitue dès lors une habileté favorable au développement individuel, tant dans les capacités d’adaptation qu’elle permet que dans les objectifs individuels et identitaires qu’elle crée à long terme. Son socle épisodique la rend de fait sensible à toute altération de la mémoire, l’incapacité à mémoriser et à rappeler des événements du passé pouvant fortement altérer la capacité à imaginer des événements à venir. Ce travail propose de revenir sur ce lien démontré entre mémoire épisodique et projection future, notamment par l’observation d’une atteinte simultanée des capacités mnésiques et projectives, premièrement dans le domaine de la neuropsychologie clinique, deuxièmement dans le cadre de pathologies psychiatriques et neurologiques. La caractéristique identitaire de la projection future est également discutée, notamment dans sa contribution à la création d’objectifs individuels futurs et dans son importance thérapeutique dans le traitement de diverses psychopathologies. Enfin, nous considérons le développement de nouvelles études démontrant aujourd’hui un effet « à double tranchant » de la projection future, à la fois vecteur d’un épanouissement de soi profond et possiblement créateur d’une anxiété d’avenir croissante, délétère à long terme

Les syndromes amnésiques : du neurone à la prise en charge

International audienc

L’identité : une représentation de soi qui accommode la réalité

International audienc

Évaluation neuropsychologique de la mémoire épisodique

International audienc

L'ictus amnésique idiopathique

International audienc

Self-awareness in Transient Global Amnesia: distinguishing the effects of transient memory disorder vs. pre-existing vulnerability factors

International audienceNumerous evidences suggest the existence of relationships between the impairment of episodic memory, acute stress exposure and variations in self-awareness (SA). Here, we examined 27 patients presenting transient global amnesia (TGA), a clinical condition which combines episodic amnesia and high anxiety, thanks to state and trait questionnaires of SA. We observed variation of SA depending on the stage of TGA (acute, recovery and follow-up). We also found preexisting differences in patient's awareness of their own image when the precipitating event was physical, encouraging us to give more consideration to the social determinants of stress in physiological cascade of TGA