Mise en place et fonctionnement d'une unité de médecine pour adolescents dans un service de pédiatrie générale (l'expérience du centre hospitalier Mémorial France-Etats-Unis de Saint-Lô (Manche))

CAEN-BU Médecine pharmacie (141182102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Vers une neuropsychologie sociale

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Cognitive reserve, recollection and familiarity in normal aging, Mild Cognitive Impairment and Alzheimer’s disease

peer reviewe

Impairment of social cognition in neurological diseases

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An exploration of the semantic network in Alzheimer’s disease: Influence of emotion and concreteness of concepts

International audienceSemantic deficits are often reported in even the very early stages of Alzheimer’s disease (AD), but investigations usually focus on concrete and non-emotional entities, ignoring the broad range of concepts that feature in everyday conversations. Emotional concepts (e.g., snake) have been found to be processed more accurately than neutral ones (e.g., chair) in AD. Our aim here was therefore to explore the dimensions of both concreteness and emotion within the semantic framework, and in particular to determine whether abstract emotional words (e.g., grief) are processed as accurately as concrete emotional ones (e.g., snake) in AD. We administered a semantic priming task (lexical decision), yielding an implicit measurement of semantic memory, to 15 patients with AD and 31 normal controls. Concrete and abstract word pairs either shared a semantic relationship (e.g., table-chair, motive-reason), a semantic and emotional relationship (e.g., snake-viper; grief-sadness), or no relationship at all (e.g., pencil-horse). On the basis of response time differences between these conditions, we obtained four semantic priming (SP) scores: concrete neutral SP, abstract neutral SP, concrete emotional SP, and abstract emotional SP. In the AD group, the SP score for abstract neutral concepts was not significant, and significantly below the other three SP scores, that seems to reflect a major deterioration in these concepts. An abnormal hyperpriming effect was observed in the concrete neutral SP condition (SP score significantly higher than that of controls), reflecting a partial deterioration in these concepts. These results suggest that, without an emotional relationship, abstract words deteriorate more quickly than concrete words. No such dissociation linked to the concreteness effect was observed with emotional words. Therefore, in AD, emotional concepts would be affected later, be they concrete or abstract

Can the emotional connotation of concepts modulate the lexico-semantic deficits in Alzheimer's disease?: Emotion and semantic memory in Alzheimer's disease

International audienceSemantic memory impairments are a common symptom of Alzheimer's disease (AD) and may occur at a relatively early stage. These disturbances can be evidenced by a hyperpriming effect (greater semantic priming in AD patients than in controls). Up till now, very few studies of semantic memory have included emotionally charged concepts. Our aim was therefore to study the semantic processing of such concepts, as opposed to neutral ones, in early AD. Given that emotional processes are relatively preserved at the beginning of the disease compared with other cognitive functions, we expected that an emotional connotation would influence the spreading activation of words and affect some of the impairments in semantic processing. We administered a semantic priming task (lexical decision task) implicitly assessing semantic memory to 26 patients with AD and 26 normal controls. Primes and targets either had a semantic relationship (e.g. tiger-lion), a semantic and emotional (positive or negative) relationship (e.g. slap-smack) or no relationship at all (e.g. chair-horse), or else belonged to a word-nonword condition (e.g. window-inuly). Compared with controls, the patients showed pathological hyperpriming effects in all conditions, especially in the emotional conditions. Hyperpriming implies a deterioration in specific attributes, as it is difficult to tell two concepts apart once their distinctive attributes have been lost. These results suggest that emotional concepts, like neutral ones, lose some of their distinctive attributes in early AD, and as the emotional processes are preserved, there is greater similarity between close emotional concepts than between close neutral concepts

Role of context in affective theory of mind in Alzheimer's disease Running title Context and affective ToM in AD

International audienceAffective theory of mind (ToM) is defined as the ability to deal with affective mental states. Attributing an affective mental state from a facial expression relies mainly on processes that allow information in the environment to be perceived and decoded. Reasoning processes are required when information is not directly available in the environment (e.g., when making an affective mental state attribution in a social situation where there is no visible facial expression of emotion). Although facial emotion decoding deficits have been reported in Alzheimer's disease (AD), few studies have assessed emotional reasoning processes. Long-term social knowledge may also contribute to mental state attribution, given its involvement in social situations, but the links between these two domains have not yet been properly explored. The aim of the present study was therefore to assess both decoding and reasoning processes in AD, as well as the effect of context on emotion attribution (i.e., whether prior presentation of a congruent vs. noncongruent social situation influences emotion recognition from faces). We also aimed to improve current understanding of the relationship between ToM processes and social knowledge. Participants were 20 patients with AD, 20 healthy older individuals, and 20 healthy young individuals. They performed three tasks testing ToM: a context task (emotion attribution in a social situation); a face task (facial emotion recognition); and a context-face task (determining whether the facial emotion was consistent with the emotion inferred from the social situation, e.g., an embarrassing situation followed by a proud face). All participants underwent a neuropsychological battery that included an assessment of social norm knowledge (e.g., determining whether it is socially acceptable to phone in a church). Results showed deficits in the patients with AD for decoding emotions from faces and for reasoning about emotions inferred from a social context. Patients were found to consider contextual information in such a way that congruency either helped or hindered the decoding of stimuli in the environment. As expected, we found that ToM abilities were linked to social norm knowledge. Overall, our findings suggest that patients with AD have difficulty attributing emotional mental states, and deficits in social norm knowledge and the presence of incongruent information may heighten this difficulty

When the zebra loses its stripes but is still in the savannah: results from a semantic priming paradigm in semantic dementia.

International audienceStudies using semantic priming paradigms to measure the integrity of the features underlying concepts in semantic dementia (SD) reported differential impairment, in that functional features appeared to be more robust to brain damage than other features, such as perceptual ones. However, these prior studies were single case reports and the inclusion of too many heterogeneous features under the "functional features" heading casts doubts on their apparent preservation. To verify the robustness of functional features compared with perceptual ones, we carried out a group study where we deliberately restricted the exploration of semantic features to two clearly defined types of attribute: visuoperceptual ("visual") versus contextual-functional ("contextual"). We administered an implicit lexical-decision priming task to 8 SD patients and 31 healthy matched controls, at baseline. Four of the patients underwent a follow-up assessment at one year. For controls, we found a significant priming effect in the visual condition, but not in the contextual one, whereas the SD group exhibited the reverse pattern of performances. The follow-up data provided evidence of the robustness of the dissociation between priming performances in the two attribute conditions. The fact that a particular priming effect was observed in the SD patients but not in controls could be regarded as a sign of semantic disequilibrium. Since perceptual features have been shown to be a core determinant of similarity-based/taxonomic relationships, whereas complementary-based/thematic processing relies mainly on contextual relationships, we interpreted our findings in terms of the differential recruitment of one of the two systems of semantic relationships (taxonomic vs. thematic). Moreover, these two distinct and parallel systems have previously been reported to coexist - and compete - in healthy adults. We thus argue that controls automatically drew on similarity-based/taxonomic relationships, leading to a significant priming effect for visual features but not for contextual ones. By contrast, their impaired perceptual features forced the SD patients to resort to the system of thematic relationships

La variante frontale de la maladie d'Alzheimer Frontal variant of Alzheimer's disease

International audienceDes formes atypiques de la maladie d’Alzheimer (MA) sont décrites depuis longtemps, mais ce n’est que récemment que les variantes aphasiques, frontales et visuo-spatiales ont été intégrées aux critères de diagnostic clinique et de recherche de la MA. Il est aujourd’hui possible d’établir, in vivo, un diagnostic de variante frontale de la MA (vf-MA) avec un haut degré de probabilité, en confrontant le profil neuropsychologique et les biomarqueurs. Toutefois, le profil neuropsychologique et comportemental des patients présentant une vf-MA est encore mal connu, menant souvent à des difficultés de diagnostic et à une confusion avec la variante comportementale des dégénérescences lobaires frontotemporales (vc-DLFT). L’évaluation de la cognition sociale semble être une piste prometteuse dans le cadre de la contribution au diagnostic différentiel entre la vf-MA, la MA et la vc-DLFT

Les altérations de la mémoire dans le trouble de stress post-traumatique

International audiencePost-Traumatic Stress Disorder (PTSD) is a disorder that develops following the experience of a highly stressful event, which involves a confrontation with death or the threat of death, serious injury or sexual violence. It is characterized by symptoms such as intrusions, avoidance and hypervigilance. According to the literature, PTSD is associated with an imbalance between a privileged memorization of the emotional and sensory aspects of the traumatic event and a failure to memorize the contextual aspects. That is why PTSD is now considered a memory disorder whose effects extend to several components. In this review article, we focus on how PTSD affects long-term memory. The first part describes the long-term effects of PTSD on episodic memory with emphasis on the difficulties in encoding certain elements of the traumatic event and their consequences. These difficulties may be manifested in the narration of the trauma, with a discourse of the traumatic event lacking in contextual details. They may also lead to reliving and generalizing the fear to other contexts, whether they are related to the trauma or not. The second part of the article discusses how PTSD affects autobiographical memory and has consequences for the construction of identity and the perception of the past, present and future of people with this disorder. Autobiographical memory, which plays a key role in the storage of past personal memories as well as in identity formation, shows several forms of disruption induced by PTSD. First, a decrease in contextual details associated with memories of the personal past is observed, meaning that people with PTSD tend to remember their past experiences less accurately. Second, a propensity to project the future in a more negative and unpredictable manner is evidenced, related to a feeling of uncertainty about the future in PTSD suffering individuals. Finally, alterations in the encoding of present events due to the disruptive effects of post-traumatic stress symptoms during the encoding process are also identified.Le Trouble de Stress Post-Traumatique (TSPT) est une pathologie qui se développe chez une personne qui a fait l’expérience d’un événement hautement stressant impliquant une confrontation à la mort ou à une menace de mort, à une blessure grave ou à des violences sexuelles. Ce trouble se caractérise par plusieurs symptômes dont les intrusions, l’évitement et l’hypervigilance. Le TSPT est associé à un déséquilibre entre une mémorisation exacerbée des aspects émotionnels et sensoriels de l’événement traumatique et un défaut de mémorisation des aspects contextuels. En conséquence, le TSPT est aujourd’hui considéré comme un trouble de la mémoire dont les retentissements s’étendent à plusieurs de ses composantes. Cet article expose les conséquences du TSPT sur la mémoire à long terme et met la focale sur deux mécanismes : l’encodage partiel de l’événement traumatique en mémoire épisodique et l’influence de cette expérience traumatique sur les souvenirs personnels en mémoire autobiographique. L’article aborde en première partie les difficultés d’encodage de certains éléments de l’événement traumatique et leurs conséquences, comprenant les reviviscences ainsi que la persistance et la généralisation de la peur à d’autres contextes plus ou moins liés à l’événement traumatique. La deuxième partie aborde la façon dont le trouble affecte la mémoire autobiographique et l’identité en occasionnant une réduction de la précision des événements du passé, des altérations de la capacité à se projeter dans des événements futurs et un encodage incomplet de nouveaux événements