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International audience; The ability to modulate our emotional experience, depending on our current goal and context, is of critical importance for adaptive behavior. This ability encompasses various emotion regulation strategies, such as fictional reappraisal, at stake whenever one engages in fictional works (e.g., movies, books, video games, virtual environments). Neuroscientific studies investigating the distinction between the processing of real and fictional entities have reported the involvement of brain structures related to self-relevance and emotion regulation, suggesting a threefold interaction between the appraisal of reality, aspects of the Self, and emotions. The main aim of this study is to investigate the effect of implicit fictional reappraisal on different components of emotion, as well as on the modulatory role of autobiographical and conceptual self-relevance. While recording electrodermal, cardiac, and brain activity (EEG), we presented negative and neutral pictures to 33 participants, describing them as either real or fictional. After each stimulus, the participants reported their subjective emotional experience, self-relevance of the stimuli, as well as their agreement with their description. Using the Bayesian mixed-modeling framework, we showed that stimuli presented as fictional, compared with real, were subjectively appraised as less intense and less negative, and elicited lower skin conductance response, stronger heart-rate deceleration, and lower late positive potential amplitudes. Finally, these phenomenal and physiological changes did, to a moderate extent, rely on variations of specific aspects of self-relevance. Implications for the neuroscientific study of implicit emotion regulation are discussed.

The present study aimed at exploring the effect of stereotype threat on the controlled part of memory in older adults using a deep level of processing, namely, self-reference encoding. To meet this objective, 25 younger adults and 25 older adults performed a Remember/Know recognition task following self-reference versus other-reference encoding of adjective traits, under stereotype threat or not. The results indicated that under stereotype threat, older adults’ production of Remember responses was specifically impaired following self-reference encoding. Moreover, whereas executive functioning and group identification did not moderate stereotype threat effect, measure of self-worth did. These findings suggest that stereotype threat in older adults may be a self-concept threat and that moderators of stereotype threat found in other groups (i.e., group identification and executive functioning) may not be generalised to this group. Rather, as stereotype threat in aging may represent a threat to the self, self-worth might have a central role, whereby individuals with high self-worth remain self-confident even under stereotype threat and are thus able to down-regulate their negative affects to face such a threat.

International audience; Few studies have investigated the link between episodic memory and presence: the feeling of " being there " and reacting to a stimulus as if it were real. We collected data from 244 participants after they had watched the movie Avengers: Age of Ultron. They answered questions about factual (details of the movie) and temporal memory (order of the scenes) about the movie, as well as their emotion experience and their sense of presence during the projection. Both higher emotion experience and sense of presence were related to better factual memory, but not to temporal order memory. Crucially, the link between emotion and factual memory was mediated by the sense of presence. We interpreted the role of presence as an external absorption of the attentional focus toward the stimulus, thus enhancing memory encoding. Our findings could shed light on the cognitive processes underlying memory impairments in psychiatric conditions characterized by an altered sense of reality. " Virtual Reality is the representation of possible worlds and possible selves, with the aim of making them appear as real as possible—i-deally, by creating a subjective sense of " presence " in the user. Interestingly, some of our best theories of the human mind and conscious experience describe it in a very similar way " Thomas Metzinger, " 2016: What do you consider the most interesting recent scientific news? " Edge.org.

Objective: This study was designed to improve our understanding of prospective memory (PM) changes in ageing, and to identify the cognitive correlates of PM decline, using a virtual environment, to provide a more realistic assessment than traditional laboratory tasks. Design: Thirty-five young and 29 older individuals exposed to a virtual town were asked to recall three event-based intentions with a strong link between prospective and retrospective components, three event-based intentions with a weak link, and three time-based intentions. They also underwent retrospective episodic memory, executive functions, binding in working memory, processing speed, and time estimation assessments. Results: Older individuals recalled fewer intentions than young adults. While age-related PM decline affected the recall of both prospective and retrospective components, the recall of the latter seemed more challenging for older individuals when the link was weak. This PM decline was linked to an age-related decline in the binding process in working memory, as well as in processing speed, executive functioning, and episodic memory, depending on the nature of intentions. Conclusion: PM appears to be sensitive to ageing, even when the device is thought to be ecological. This decline is particularly pronounced when controlled processes are needed.

The origins of poor insight in schizophrenia are still unclear. We contrasted the changes in clinical insight, basic cognitive processes, autobiographical memory and metacognition in 63 outpatients with schizophrenia pseudo-randomly assigned to one of three cognitive remediation groups: one targeting basic cognitive processes (RECOS), a second autobiographical memory (REMAu), and a third metacognitive deficits (MBCT). Three dimensions of insight (awareness of: mental illness, benefit of treatment, psychosocial consequences) improved after treatment, regardless of the group. In addition, the REMAu and MBCT showed an improvement on other dimensions of insight (symptomatic awareness and symptomatic attribution, respectively). Poor insight and its improvement after treatment were best predicted by a combination of basic cognitive, autobiographical and metacognitive measures. This study supports a multidimensional conception of insight and recommends the combination of remediation therapies to improve clinical insight in schizophrenia.

In the last two decades, the study of memory processes has been expanded to encompass the processes involved in foreseeing events in the future dimension. The mental time travel is a mental ability, which allows individuals not only to go back in time but also to foresee specific future events (Suddendorf and Corballis, 1997). The ability to project the self forward in time to pre-experience personal events is referred to as episodic future thinking (EFT) (Atance and O’Neill, 2001). This capacity has a strong adaptive and social value (Tulving, 2002; D’Argembeau and Van der Linden, 2012). While evidence is accruing regarding the existence of semantic general forms of prospection (Klein, 2013; Irish et al., 2016), it seems relevant to envisage the role of personal semantic representations in prospection. Here we focus on the impact of personal semantics depending on temporal distance in episodic forms of foresight. In what follows we (I) give a brief overview of different EFT accounts, (II) discuss the role of personal semantics in EFT, (III) propose a neurocognitive model, in which the role of personal semantic information in EFT is defined as a function of temporal distance, (IV) speculate about temporally graded EFT deficits in Alzheimer’s disease and semantic dementia.

Autobiographical memory (AM) underlies the formation and temporal continuity over time of personal identity. The few studies on sex-related differences in AM suggest that men and women adopt different cognitive or emotional strategies when retrieving AMs. However, none of the previous works has taken into account the distinction between episodic autobiographical memory (EAM), consisting in the retrieval of specific events by means of mental time travel, and semantic autobiographical memory (SAM), which stores general personal events. Thus, it remains unclear whether differences in these strategies depend on the nature of the memory content to be retrieved. In the present study we employed functional MRI to examine brain activity underlying potential sex differences in EAM and SAM retrieval focusing on the differences in strategies related to the emotional aspects of memories while controlling for basic cognitive strategies. On the behavioral level, there was no significant sex difference in memory performances or subjective feature ratings of either type of AM. Activations common to men and women during AM retrieval were observed in a typical bilateral network comprising medial and lateral temporal regions, precuneus, occipital cortex as well as prefrontal cortex. Contrast analyses revealed that there was no difference between men and women in the EAM condition. In the SAM condition, women showed an increased activity, compared to men, in the dorsal anterior cingulate cortex, inferior parietal and precentral gyrus. Overall, these findings suggest that differential neural activations reflect sex-specific strategies related to emotional aspects of AMs, particularly regarding SAM. We propose that this pattern of activation during SAM retrieval reflects the cognitive cost linked to emotion regulation strategies recruited by women compared to men. These sex-related differences have interesting implications for understanding psychiatric disorders with differential sex prevalence and in which one of key features is overgenerality in AM.

International audience; Because of a dramatic increase of older people worldwide, screening for prodromal state of Alzheimer disease (AD) is a major societal challenge. Many individuals diagnosed with prodromal AD, do not convert to AD, some remaining stable and others reversing back to normal. We argue that an important source of this overdiagnosis comes from negative aging stereotypes (eg, the culturally shared beliefs that aging inescapably causes severe cognitive decline and diseases). Many laboratory studies show that such stereotypes impair memory performance in healthy older adults, producing inflated age differences. Research is needed to examine how aging stereotypes implicitly permeate neuropsychological testing and contribute to false positives.

International audience; The question of an emotional memory enhancement in aging, and of a positivity bias in particular, has been the subject of numerous empirical studies in the last decade. However, the roots of such positive preference are not yet well established. Partisans of a motivation-based perspective contend with those arguing that positivity is related to a cognitive or neural degradation. The aim of this study was to introduce some elements concerning positivity effect in aging. We compared immediate (i.e., immediate recall) versus delayed (i.e., delayed recall and recognition) emotional memory performance in 38 young adults, 39 old adults, 37 very old adults, and 41 Alzheimer’s disease patients. Moreover, we manipulated the encoding instruction: Either participants received no particular processing instruction, or they had to process the material in a semantic way. The results indicated that the positivity bias is most likely to occur in individuals whose cognitive functions are preserved, after long retention delay, and in experimental conditions that do not constrain encoding. We concluded by highlighting that although these findings seem to be better in line with the motivation, rather than the degradation, perspective, they do not fully support either theory. (PsycINFO Database Record (c) 2017 APA, all rights reserved)

International audience; The self-reference effect (SRE) has been shown to benefit episodic memory in healthy individuals. In healthy aging, its preservation is acknowledged, but in Alzheimer’s disease (AD), the jury is still out. Furthermore, there has yet to be a study of the SRE in amnestic mild cognitive impairment (aMCI). As self-reference implies subjective self-representations, and positive information enhance memory performance, we set out to examine the effects of 1) material and 2) identity valence on the SRE across the early stages of AD. Twenty healthy older individuals and 40 patients (20 diagnosed with aMCI and 20 diagnosed with mild AD) performed a memory task. Participants had to judge positive and negative personality trait adjectives with reference to themselves or to another person, or else process these adjectives semantically. We then administered a recognition task. Participants also completed a questionnaire on identity valence. Among healthy older individuals, the SRE benefited episodic memory independently of material and identity valence. By contrast, among aMCI patients, we only observed the SRE when the material was positive. When self-referential material was negative, patients’ performance depended on the valence of their self-representations: negative self-representations correlated with poor recognition of negative self-referential adjectives. Finally, performance of patients with mild AD by condition and material valence were too low and inappropriate to be subjected to relevant analyses. The persistence of an SRE for positive adjectives in aMCI suggests the existence of a positivity effect for self-related information, which contributes to wellbeing. The absence of an SRE for negative adjectives, which led aMCI patients to dismiss negative self-related information, could be due to low self-esteem. These results corroborate the mnenic neglect model and point out the importance of the psychoaffective dimension in patients with aMCI, which could constitute a major factor for the preservation of their self-esteem and self-related memory.Keywords: self-reference effect; positivity effect; episodic memory; amnestic mild cognitive impairment; Alzheimer’s disease

Prospective memory (PM) refers to a complex cognitive ability that underpins the delayed execution of previously formulated intentions. PM performance declines early in normal aging and this process is accentuated in Alzheimer's disease. The left frontopolar cortex (BA10) has been consistently assigned a major role in PM functioning, but whether it can be noninvasively modulated to enhance PM perfor- mance in aged people has not been addressed so far. Here, we investigated the effects of modulating left BA10 by means of theta burst stimulation (TBS), using either excitatory (intermittent TBS), inhibitory (continuous TBS) or control (vertex) TBS in healthy aged subjects. The behavioral effects were assessed using a reliable and ecological virtual reality PM task that included both event- and time-based retrievals. As compared with vertex stimulation, event-based PM performance significantly improved after excit- atory stimulation, whereas inhibitory stimulation had no significant effect. Additionally, and across the different types of stimulation, performance for congruent links between the event-based PM cue and the action to be performed was significantly better as compared with incongruent links. In conclusion, intermittent TBS might provide a relevant interventional strategy to counteract the decline of cognitive functions and memory abilities in normal aging.

International audience; Cancer involves stressful events. One aspect of cognition that is impacted by stress is episodic autobiographical memory (EAM). EAM is intimately linked to self-representation. Some studies have revealed impairment of EAM in patients with breast cancer in remission. Yet, these studies failed to differentiate between the influence of adjuvant treatments and that of psychosocial factors. We therefore assessed the psychological impact of breast cancer diagnosis on EAM and self-representation profiles prior to any adjuvant treatment. Patients newly diagnosed with breast cancer (n=31) and women without any history of cancer (n=49) were compared on state anxiety, EAM and its emotional characteristics, and self-representations. The most anxious patients retrieved fewer emotional details for memories than the controls, and had lower self-representation scores than the least anxious patients, who had no deficits in emotional detail retrieval. Our results revealed distinct EAM profiles for patients, reflecting two contrasting modes of coping with breast cancer.

The College de France was the first university-level institution to actually recognize psychology as an academic subject (Ribot in 1888 and Janet in 1902). We present here a historical note on the introduction of Henri Piéron at the Collège de France in 1923. The objective of this paper is to describe, on the basis of available historical documents, the events that led to the creation of the chair of 'Physiology of Sensation'. We underline the important roles played by Pierre Janet and Jean Nageotte in this creationand we describe the events that took place at the Collège de France.; Le Collège de France fut la première institution de l'enseignement supérieur à reconnaître officiellement la psychologie (Ribot en 1888 et Janet en 1902). Nous présentons ici une note historique sur l'introduction en 1923 de Henri Piéron au Collège de France. L'objectif de cet article est de décrire, sur la base des documents historiques disponibles, les éÎnements qui ont conduit à la création de la chaire de « Physiologie des sensations ». Nous avons souligné le rôle important de Pierre Janet et Jean Nageotte dans cette création et nous avons présenté en résumé les éÎnements qui se sont déroulés au Collège de France.

None of the previous studies on aging have tested the influence of action with respect to the degree of interaction with the environment (active or passive navigation) and the source of itinerary choice (self or externally imposed), on episodic memory encoding. The aim of this pilot study was to explore the influence of these factors on feature binding (the association between what, where and when) in episodic memory and on the subjective sense of remembering. Navigation in a virtual city was performed by 64 young and 64 older adults in one of four modes of exploration: (1) passive condition where participants were immersed as passengers of a virtual car (no interaction, no itinerary control), (2) itinerary control (the subject chose the itinerary, but did not drive the car), (3) low or (4) high navigation control (the subject just moved the car on rails or drove the car with a steering wheel and a gas pedal on a fixed itinerary, respectively). The task was to memorize as many events encountered in the virtual environment as possible along with their factual (what), spatial (where), and temporal (when) details, and then to perform immediate and delayed memory tests. An age-related decline was evidenced for immediate and delayed feature binding. Compared to passive and high navigation conditions, and regardless of age groups, feature binding was enhanced by low navigation and itinerary control conditions. The subjective sense of remembering was boosted by the itinerary control in older adults. Memory performance following high navigation was specifically linked to variability in executive functions. The present findings suggest that the decision of the itinerary is beneficial to boost episodic memory in aging, although it does not eliminate age-related deficits. Active navigation can also enhance episodic memory when it is not too demanding for subjects' cognitive resources.

International audience; The purpose of the present study was to investigate emotional memory enhancement (EME) in Alzheimer's disease (AD). In particular, we were interested in exploring which memory process (i.e., recollection or familiarity) could be improved by emotional information in the course of the disease. Eighteen AD patients were compared with 15 normal controls on the Remember/Know/Guess paradigm following encoding of emotional and neutral words. AD patients' recollective experience was improved for emotional compared to neutral words to the same extent as that of normal controls, whereas emotion had no effect on participants' memory performance involving familiarity processes. Our results showed that AD patients' memory can be enhanced qualitatively but not quantitatively by an emotional material. Furthermore, we found that AD patients were as able as normal controls to benefit from the emotional content of information to improve the recollection of details.

International audience; Information that is processed with reference to oneself, i.e. Self-Referential Processing (SRP), is generally associated with better remembering compared to information processed in a condition not related to oneself. This positive effect of the self on subsequent memory performance is called as Self-Reference Effect (SRE). The neural basis of SRE is still poorly understood. The main goal of the present work was thus to highlight brain changes associated with SRE in terms of activity and functional coupling and during both encoding and retrieval so as to assess the relative contribution of both processes to SRE. For this purpose, we used an fMRI event-related self-referential paradigm in 30 healthy young subjects and measured brain activity during both encoding and retrieval of self-relevant information compared to a semantic control condition. We found that SRE was associated with brain changes during the encoding phase only, including both greater activity in the medial prefrontal cortex and hippocampus, and greater functional coupling between these brain regions and the posterior cingulate cortex. These findings highlight the contribution of brain regions involved in both SRP and episodic memory and the relevance of the communication between these regions during the encoding process as the neural substrates of SRE. This is consistent with the idea that SRE reflects a positive effect of the reactivation of self-related memories on the encoding of new information in episodic memory.

International audience; Semantic dementia (SD) is characterized by gradual loss of semantic memory. While episodic autobiographical memory seems relatively preserved, behavioral studies suggest that episodic future thinking is impaired. We used fMRI to measure brain activity in four SD patients (JPL, EP, LL, EG) while they envisioned future events and remembered personal past events. Twelve healthy elders served as controls. Episodic quality, emotion, mental imagery and level of consciousness (via remember/know judgements) were checked at debriefing. We analyzed the future compared to the past for each patient. All patients presented lateral temporal atrophy, but varied in terms of frontal and anterior hippocampal atrophy. Patient JPL presented atrophy in bilateral superior medial frontal gyri and left anterior hippocampus and was unable to engage in episodic future thinking, despite hyperactivations in frontal and occipital regions. Patient EP presented no atrophy in the anterior hippocampus, but atrophy in bilateral superior medial frontal gyrus and had difficulties to engage in episodic future thinking. Patient LL presented atrophy in left anterior hippocampus, but hyperactivated its right counterpart for future compared to past thinking, permitting her to project efficiently in the future in an episodic way. Patient EG presented no atrophy in the superior medial frontal gyri or anterior hippocampi and was able to engage in episodic future thinking. Altogether, patients' future projections differed depending on the severity and localization of their atrophy. The functional integrity of bilateral superior medial frontal gyri and anterior hippocampus appear crucial for episodic future thinking: atrophy of both structures strongly impairs future projection, while integrity of these structures or hyperactivation of residual tissue normalizes episodic future projection.

International audience; Age-related changes in autobiographical memory (AM) recall are characterized by a decline in episodic details, while semantic aspects are spared. This deleterious effect is supposed to be mediated by an inefficient recruitment of executive processes during AM retrieval. To date, contrasting evidence has been reported on the neural underpinning of this decline, and none of the previous studies has directly compared the episodic and semantic aspects of AM in elderly. We asked 20 young and 17 older participants to recall specific and general autobiographical events (i.e., episodic and semantic AM) elicited by personalized cues while recording their brain activity by means of fMRI. At the behavioral level, we confirmed that the richness of episodic AM retrieval is specifically impoverished in aging and that this decline is related to the reduction of executive functions. At the neural level, in both age groups, we showed the recruitment of a large network during episodic AM retrieval encompassing prefrontal, cortical midline and posterior regions, and medial temporal structures, including the hippocampus. This network was very similar, but less extended, during semantic AM retrieval. Nevertheless, a greater activity was evidenced in the dorsal anterior cingulate cortex (dACC) during episodic, compared to semantic AM retrieval in young participants, and a reversed pattern in the elderly. Moreover, activity in dACC during episodic AM retrieval was correlated with inhibition and richness of memories in both groups. Our findings shed light on the direct link between episodic AM retrieval, executive control, and their decline in aging, proposing a possible neuronal signature. They also suggest that increased activity in dACC during semantic AM retrieval in the elderly could be seen as a compensatory mechanism underpinning successful AM performance observed in aging. These results are discussed in the framework of recently proposed models of neural reorganization in aging.

An experiment was run to complete our understanding of the involvement of working memory (WM) components in the construction of a spatial model from visual input, considering some of the visuospatial abilities known to modulate performance. In addition, to allow for consideration of the flexibility of the spatial representation, routes in a virtual environment were presented with a route perspective, and tests were presented with route and survey perspectives. The results indicate that the verbal and spatial WM are only involved in the memorisation of certain types of information, and that their involvement depends on the change of perspective necessitated by the task. Thus, even when the learning material and the tests used to assess performance are only visual, a verbal recoding of some information is necessary. Moreover, individual differences modulate the involvement of WM; an individual with higher visuospatial capacities uses more spatial WM than an individual with lower spatial capacities.

The aim of this study is to broaden our understanding of the construction and early decline of spatial mental representations in route learning, considering the extent to which spatial ability and age-related differences in environment learning interact. The experiment examines spatial mental representation derived from taking a realistic route acquired using virtual environment and compares individuals different in age but with similar spatial ability. A sample of 34 young (20–30 years) and 30 middle-aged (50–60 years) females with good mental rotation ability were chosen. Participants learned a complex route through its presentation in a virtual environment and then performed a series of tasks (landmark recognition, location of landmarks and verification of spatial relations). Results show that the two participant age groups had similar performance in landmark recognition task and in verification of sentences describing direct spatial relations; instead, the middle-aged group showed a poorer performance than younger in their ability to locate landmarks and to judge the truth of indirect spatial sentences. These results first suggest that spatial abilities have to be seriously considered to avoid any confusion with age, as age-related differences are attenuated when individuals are different in age but similar in spatial ability. Second they confirm a specific difficulty of older participants to handle spatial information in a global configuration.

The self has been the topic of philosophical inquiry for centuries. Neuropsychological data suggest that the declarative self can be fractionated into three functionally independent systems processing personal information at several levels of abstraction, including episodic memories of one's own life (episodic autobiographical memory, EAM), semantic knowledge of facts about one's own life (semantic autobiographical memory, SAM), and semantic summary representations of one's personal identity (conceptual self, CS). Our proposal here was to present a comprehensive description of the neural networks underpinning self‐representations. To this aim, we performed three meta‐analyses, one each for EAM, SAM, and CS, using the activation likelihood estimation (ALE) method. We expected a shift from posterior to anterior structures associated with the incrementally increasing level of abstraction of self‐representations. The key finding was that EAM predominantly activates posterior and limbic regions including hippocampus. SAM is associated with anterior activations and also posterior and limbic activations in a lesser degree than EAM. CS mainly recruits medial prefrontal structures. Interestingly, medial prefrontal cortex is activated irrespective of the level of abstraction, but a more caudal part is recruited during CS, while SAM and EAM activate more rostral portions. To conclude, in line with the previous proposals, our results corroborate the idea that the declarative self is not monolithic but a multidimensional construct comprising distinct representations at different levels of abstraction. Hum Brain Mapp, 2013. © 2011 Wiley Periodicals, Inc.

International audience; Semantic dementia is characterized by semantic deficits and behavioural abnormalities that occur in the wake of bilateral inferolateral and predominantly left-sided anterior temporal lobe atrophy. The temporal poles have been shown to be involved in theory of mind, namely the ability to ascribe cognitive and affective mental states to others that regulates social interactions by predicting and interpreting human behaviour. However, very few studies have examined theory of mind in semantic dementia. In this study, we investigated both cognitive and affective theory of mind in a group of patients with semantic dementia, using separate objective and subjective assessment tasks. Results provided objective evidence of an impact of semantic dementia on cognitive and affective theory of mind, consistent with the patients' atrophy in the left temporal lobe and hypometabolism in the temporal lobes and the medial frontal cortex. However, the subjective assessment of theory of mind suggested that awareness of the affective but not cognitive theory of mind deficit persists into the moderate stage of the disease.

Studies of autobiographical memory in semantic dementia (SD) have yielded either a reversed temporal gradient or spared performances across the entire lifetime. This discrepancy might be owing to the fact that these studies did not take into account disease severity. Our aim was to study patterns of autobiographical memory impairment according to disease severity and to unravel their mechanisms in 14 SD patients, using an autobiographical memory task assessing overall and strictly episodic memories across the entire lifetime. We divided our patients in 2 subgroups of 7 patients each, one mild and one moderate according to their level of disease severity. The results indicated for the mild subgroup selective preserved performances for the most recent time period (last 12 months period) for both autobiographical memory scores. In the moderate subgroup, performances were impaired for both scores whatever the time period. Within-group comparisons across time periods showed a recency effect and a reminiscence bump in the mild subgroup and only a less important recency effect in the moderate subgroup, suggesting that with disease severity, old memories (reminiscence bump) tend to vanish and even recent memories are less well retrieved. A correlation analysis was carried out on the entire group, between the overall autobiographical memory score and performances provided by a general cognitive evaluation (semantic memory, executive functions, working and episodic memory). The results of this analysis reflect that mechanisms of disruption of autobiographical memory in SD predominantly involve a deficit of storage of semantic information in addition to faulty executive retrieval strategies. Finally, our result and those of the literature suggest the existence of 3 distinct autobiographical memory impairment patterns in SD according to disease severity: firstly preserved performances whatever the time period, secondly a reversed temporal gradient with a reminiscence bump and thirdly the appearance of a "step-function".

This study aims to investigate autonoetic consciousness associated with episodic autobiographical memory in patients who had undergone unilateral medial temporal lobe resection for intractable epilepsy. Autonoetic consciousness, defined as the conscious feeling of mentally travelling back in time to relive a specific event, was assessed using the Remember/Know (R/K) paradigm across different time periods as proposed in the autobiographical memory task developed by Piolino et al. (TEMPau task). Results revealed that the two patient groups (left and right temporal resection) gave reduced sense of reliving (R) responses and more familiarity (K) responses than healthy controls. This poor autonoetic consciousness was highlighted when patients were asked to justify their Remember responses by recalling sensory-perceptive, affective or spatiotemporal specific details across all life periods. These results support the bilateral MTL contribution to episodic autobiographical memory covering the entire lifespan, which is consistent with the multiple trace theory of MTL function [7,9]. This study also demonstrates the bilateral involvement of MTL structures in recalling specific details of personal events characterized by autonoetic consciousness.

International audience; Rare studies have used magnetic resonance imaging (MRI) and voxel-based morphometry (VBM) to assess atrophy, and only two positron emission tomography (PET) studies used SPM to examine functional changes in semantic dementia (SD). Our aim was to highlight both morphological and functional abnormalities in a same group of 10 SD patients, in the entire brain, using a "state of the art" methodology (optimized VBM procedure, PET data corrected for partial volume effects and voxel-based analyses). We also used an extensive neuropsychological battery. We showed that main alterations concerned the left temporal lobe, in accordance with the striking impairment of semantic memory in SD patients, as well as the hippocampal region, which may partly explain their moderate episodic memory deficits. Hypometabolism was more extensive than grey matter loss in both temporal lobes, and specifically concerned the orbitofrontal areas, consistent with the moderate impairment of executive functions and behavioural changes. While PET is more sensitive than MRI, there is striking concordance between morphological and functional abnormalities, which contrasts with the discordance observed in Alzheimer's disease and might be a typical feature of SD.

International audience; We used functional magnetic resonance imaging to determine the cerebral structures required during the recollection of episodic autobiographical memories according to 5 time periods covering the whole lifespan to test the 2 concurring models of memory consolidation, which propose either a temporary (standard model) or a permanent (multiple-trace model) role of the hippocampus in episodic memory retrieval. The experimental paradigm was specially designed to engage subjects (67.17 +/- 5.22 years old) in the retrieval of episodic autobiographical memories, whatever the time period, from personally relevant cues selected by questioning a family member. Moreover, the nature of the memories was checked at debriefing by means of behavioral measures to control the degree of episodicity. Behavioral data showed that recollected memories were characterized by specificity and details whatever their remoteness. Main neuroimaging data (Statistical Parametric Mapping 99) revealed the activation of a network including the left superior frontal gyri, bilateral precuneus/posterior cingulate and lingual gyri, left angular gyrus, and left hippocampus, although the subtraction analyses detected subtle differences between certain time periods. Small volume correction centered on the hippocampus detected left hippocampal activation for all time periods and additional right hippocampal activation for the intermediate periods. Further confirmation was provided by using a 3-way analysis of variance on blood oxygen level-dependent values, which revealed hippocampal activation whatever the time interval. The present data challenge the standard model of memory consolidation and support the multiple-trace model, instead. The comparison with previous literature stresses the idea that a bilateral involvement of the hippocampus characterizes rich episodic autobiographical memory recollection.

International audience