How Aging Affects Sleep-Dependent Memory Consolidation?

Memories are not stored as they were initially encoded but rather undergo a gradual reorganization process, termed memory consolidation. Numerous data indicate that sleep plays a major role in this process, notably due to the specific neurochemical environment and the electrophysiological activity observed during the night. Two putative, probably not exclusive, models (“hippocampo-neocortical dialogue” and “synaptic homeostasis hypothesis”) have been proposed to explain the beneficial effect of sleep on memory processes. However, all data gathered until now emerged from studies conducted in young subjects. The investigation of the relationships between sleep and memory in older adults has sparked off little interest until recently. Though, aging is characterized by memory impairment, changes in sleep architecture, as well as brain and neurochemical alterations. All these elements suggest that sleep-dependent memory consolidation may be impaired or occurs differently in older adults. This review outlines the mechanisms governing sleep-dependent memory consolidation, and the crucial points of this complex process that may dysfunction and result in impaired memory consolidation in aging

Impact of Semantic Relatedness on Associative Memory: An ERP Study

Encoding and retrieval processes in memory for pairs of pictures are thought to be influenced by inter-item similarity and by features of individual items. Using Event-Related Potentials (ERP), we aimed to identify how these processes impact on both the early mid-frontal FN400 and the Late Positive Component (LPC) potentials during associative retrieval of pictures. Twenty young adults undertook a sham task, using an incidental encoding of semantically related and unrelated pairs of drawings. At test, we conducted a recognition task in which participants were asked to identify target identical pairs of pictures, which could be semantically related or unrelated, among new and rearranged pairs. We observed semantic (related and unrelated pairs) and condition effects (old, rearranged and new pairs) on the early mid-frontal potential. First, a lower amplitude was shown for identical and rearranged semantically related pairs, which might reflect a retrieval process driven by semantic cues. Second, among semantically unrelated pairs, we found a larger negativity for identical pairs, compared to rearranged and new ones, suggesting additional retrieval processing that focuses on associative information. We also observed an LPC old/new effect with a mid-parietal and a right occipito-parietal topography for semantically related and unrelated old pairs, demonstrating a recollection phenomenon irrespective of the degree of association. These findings suggest that associative recognition using visual stimuli begins at early stages of retrieval, and differs according to the degree of semantic relatedness among items. However, either strategy may ultimately lead to recollection processes

Apprendre a réaliser une radiographie a l’aide d’un simulateur numérique

Les outils numériques transforment les pratiques pédagogiques. En particulier, les simulateurs informatiques ont pris une place importante dans la formation des professionnels de santé. Ils sont devenus le support incontournable des cours magistraux. Dans cette optique, nous avons développé un simulateur numérique d’imagerie radiologique de projection. Pour réaliser une radiographie, l’étudiant saisit, sur l’interface graphique, l’ensemble des paramètres nécessaires au fonctionnement d’un tube à rayons X. Il visualise immédiatement le cliché obtenu, en particulier les conséquences de l’utilisation de paramètres inadaptés. Ce simulateur convivial et interactif place les étudiants dans une position active. Il est un outil indispensable pour la consolidation des enseignements magistraux ainsi que pour l’évaluation du savoir-faire et du savoir-être des étudiants

Attentional capture mediates the emergence and suppression of intrusive memories

International audienceIntrusive memories hijack consciousness and their control may lead to forgetting. However, the contribution of reflexive attention to qualifying a memory signal as interfering is unknown. We used machine learning to decode the brain's electrical activity and pinpoint the otherwise hidden emergence of intrusive memories reported during a memory suppression task. Importantly, the algorithm was trained on an independent attentional model of visual activity, mimicking either the abrupt and interfering appearance of visual scenes into conscious awareness or their deliberate exploration. Intrusion of memories into conscious awareness were decoded above chance. The decoding accuracy increased when the algorithm was trained using a model of reflexive attention. Conscious detection of intrusive activity decoded from the brain signal was central to the future silencing of suppressed memories and later forgetting. Unwanted memories require the reflexive orienting of attention and access to consciousness to be suppressed effectively by inhibitory control

Attentional capture mediates the emergence and suppression of intrusive memories

International audienceIntrusive memories hijack consciousness and their control may lead to forgetting. However, the contribution of reflexive attention to qualifying a memory signal as interfering is unknown. We used machine learning to decode the brain's electrical activity and pinpoint the otherwise hidden emergence of intrusive memories reported during a memory suppression task. Importantly, the algorithm was trained on an independent attentional model of visual activity, mimicking either the abrupt and interfering appearance of visual scenes into conscious awareness or their deliberate exploration. Intrusion of memories into conscious awareness were decoded above chance. The decoding accuracy increased when the algorithm was trained using a model of reflexive attention. Conscious detection of intrusive activity decoded from the brain signal was central to the future silencing of suppressed memories and later forgetting. Unwanted memories require the reflexive orienting of attention and access to consciousness to be suppressed effectively by inhibitory control

Evaluation des effets résiduels de psychotropes sur les capacités à conduire et l'éveil : interaction médicamenteuse. In S. Gaymard, T. Tiplica (Eds), Sécurité des déplacements, protection des usagers et de l'environnement. Maîtrise des risques et prévention. Tome 1

L'utilisation d'un Îhicule associé à la consommation de psychotropes relève de pratiques relativement courantes (21% des causes d'accident en 2013 selon l'Observatoire National Interministériel de Sécurité Routière). Les données épidémiologiques et les pourcentages de consommation de médicaments ne permettent pas de faire un lien de causalité direct entre un produit donné et une éventuelle détérioration de la conduite automobile. Des études sont aujourd'hui menées pour tenter d'appréhender les facteurs influençant les variations du niveau d'éveil dans le domaine de la conduite. Notre expérience s'intègre dans ce cadre et en particulier sur l'influence de psychotropes administrés à dose thérapeutique par une prescription médicale standard. Nous avons mené une expérience de conduite sur simulateur avec des sujets sains (matures - 55-65 ans), après une nuit complète de sommeil. Dans cette expérience, les psychotropes étudiés étaient administrés seuls ou combinés et comparés à un placebo. Nous nous sommes plus particulièrement intéressés aux effets résiduels d'un hypnotique et aux effets aigus d'un analgésique. Nos résultats sur l'effet combiné d'un analgésique et d'un hypnotique ne suggèrent aucune interaction pharmacologique entre ces deux produits chez des sujets matures et sains. Cependant, nous observons des effets indépendants de chacun de ces psychotropes sur la performance de conduite aussi bien sur le plan qualitatif que quantitatifs (maintien de la trajectoire et régulation de la vitesse). Nos résultats mettent en évidence une augmentation de la somnolence avec la prise combinée d'un analgésique et d'un hypnotique lors de l'évaluation objective (EEG) après une heure de conduite simulée. Ce résultat suggère une interaction entre la durée de la tâche de conduite et la prise combinée d'un analgésique et d'un hypnotique

Avoidance Behavior Generalizes to Eye Processing in Posttraumatic Stress Disorder

International audienceBackground: Avoidance describes any action designed to prevent an uncomfortable situation or emotion from occurring. Although it is a common reaction to trauma, avoidance becomes problematic when it is the primary coping strategy, and plays a major role in the development and maintenance of posttraumatic stress disorder (PTSD). Avoidance in PTSD may generalize to non-harmful environmental cues that are perceived to be unsafe.Objective: We tested whether avoidance extends to social cues (i.e., emotional gazes) that are unrelated to trauma.Method: A total of 159 participants (103 who had been exposed to the 2015 Paris terrorist attacks and 56 who had not) performed a gaze-cueing task featuring sad, happy and neutral faces. Attention to the eye area was recorded using an eyetracker. Of the exposed participants, 52 had been diagnosed with PTSD (PTSD+) and 51 had not developed PTSD (PTSD-). As a result of the preprocessing stages, 52 PTSD+ (29 women), 50 PTSD- (20 women) and 53 nonexposed (31 women) participants were included in the final analyses.Results: PTSD+ participants looked at sad eyes for significantly less time than PTSD- and nonexposed individuals. This effect was negatively correlated with the intensity of avoidance symptoms. No difference was found for neutral and happy faces.Conclusions: These findings suggest that maladaptive avoidance in PTSD extends to social processing, in terms of eye contact and others’ emotions that are unrelated to trauma. New therapeutic directions could include targeting sociocognitive deficits. Our findings open up new and indirect avenues for overcoming maladaptive avoidance behaviors by remediating eye processing

Avoidance behaviour generalizes to eye processing in posttraumatic stress disorder

International audienceBackground: Avoidance describes any action designed to prevent an uncomfortable situation or emotion from occurring. Although it is a common reaction to trauma, avoidance becomes problematic when it is the primary coping strategy, and plays a major role in the development and maintenance of posttraumatic stress disorder (PTSD). Avoidance in PTSD may generalize to non-harmful environmental cues that are perceived to be unsafe. Objective: We tested whether avoidance extends to social cues (i.e. emotional gazes) that areunrelated to trauma.Method: A total of 159 participants (103 who had been exposed to the 2015 Paris terrorist attacks and 56 who had not) performed a gaze-cueing task featuring sad, happy and neutral faces. Attention to the eye area was recorded using an eyetracker. Of the exposed participants, 52 had been diagnosed with PTSD (PTSD+) and 51 had not developed PTSD (PTSD-). As a result of the preprocessing stages, 52 PTSD+ (29 women), 50 PTSD- (20 women) and 53 nonexposed (31 women) participants were included in the final analyses. Results: PTSD+ participants looked at sad eyes for significantly less time than PTSD- and nonexposed individuals. This effect was negatively correlated with the intensity of avoidance symptoms. No difference was found for neutral and happy faces. Conclusions: These findings suggest that maladaptive avoidance in PTSD extends to social processing, in terms of eye contact and others’ emotions that are unrelated to trauma. New therapeutic directions could include targeting sociocognitive deficits. Our findings open up new and indirect avenues for overcoming maladaptive avoidance behaviours by remediating eye processing

Alexithymia in amyotrophic lateral sclerosis and its neural correlates

International audienc

Evaluation des effets résiduels de psychotropes sur les capacités à conduire et l'éveil : interaction médicamenteuse. In S. Gaymard, T. Tiplica (Eds), Sécurité des déplacements, protection des usagers et de l'environnement. Maîtrise des risques et prévention. Tome 1

L'utilisation d'un Îhicule associé à la consommation de psychotropes relève de pratiques relativement courantes (21% des causes d'accident en 2013 selon l'Observatoire National Interministériel de Sécurité Routière). Les données épidémiologiques et les pourcentages de consommation de médicaments ne permettent pas de faire un lien de causalité direct entre un produit donné et une éventuelle détérioration de la conduite automobile. Des études sont aujourd'hui menées pour tenter d'appréhender les facteurs influençant les variations du niveau d'éveil dans le domaine de la conduite. Notre expérience s'intègre dans ce cadre et en particulier sur l'influence de psychotropes administrés à dose thérapeutique par une prescription médicale standard. Nous avons mené une expérience de conduite sur simulateur avec des sujets sains (matures - 55-65 ans), après une nuit complète de sommeil. Dans cette expérience, les psychotropes étudiés étaient administrés seuls ou combinés et comparés à un placebo. Nous nous sommes plus particulièrement intéressés aux effets résiduels d'un hypnotique et aux effets aigus d'un analgésique. Nos résultats sur l'effet combiné d'un analgésique et d'un hypnotique ne suggèrent aucune interaction pharmacologique entre ces deux produits chez des sujets matures et sains. Cependant, nous observons des effets indépendants de chacun de ces psychotropes sur la performance de conduite aussi bien sur le plan qualitatif que quantitatifs (maintien de la trajectoire et régulation de la vitesse). Nos résultats mettent en évidence une augmentation de la somnolence avec la prise combinée d'un analgésique et d'un hypnotique lors de l'évaluation objective (EEG) après une heure de conduite simulée. Ce résultat suggère une interaction entre la durée de la tâche de conduite et la prise combinée d'un analgésique et d'un hypnotique