References of "Collette, Fabienne"
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See detailSelf in Dementia
Antoine, Nicolas ULg; Genon, Sarah ULg; Bastin, Christine ULg et al

in Mishara; Corlett, P.; Fletcher, P. (Eds.) et al Phenomenological Neuropsychiatry, How Patient Experience Bridges Clinic with Clinical Neuroscience (in press)

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See detailL’impact de la réserve cognitive sur le fonctionnement exécutif au cours du vieillissement normal
Lesoinne, Alexia ULg; Simon, Jessica ULg; Gilsoul, Jessica ULg et al

Poster (2017, May 20)

Il existe une forte variabilité interindividuelle quant aux effets du vieillissement sur la cognition. Selon Stern (2009), les individus qui ont développé un haut niveau de réserve cognitive résisteraient ... [more ▼]

Il existe une forte variabilité interindividuelle quant aux effets du vieillissement sur la cognition. Selon Stern (2009), les individus qui ont développé un haut niveau de réserve cognitive résisteraient mieux aux effets du vieillissement. Afin de déterminer les facteurs de réserve cognitive qui expliquent le déclin exécutif dans le vieillissement, nous avons recruté 165 participants âgés de 59 à 81 ans. Ils ont effectué sept tâches évaluant le fonctionnement exécutif : des épreuves d’inhibition (Stroop et Incompatibilité de la TAP), de flexibilité (Flexibilité de la TAP, épreuve d’alternance arithmétique « plus-moins ») et de mise à jour (subtest Lettre-Chiffre de la MEM III, mise à jour de consonnes et tâche de 2-back). De plus, les participants ont complété différents questionnaires évaluant quatre facteurs de réserve cognitive (niveau d’études, parcours professionnel, activité physique et activités de loisir). Nous avons réalisé des analyses de régression linaire hiérarchique. Après avoir contrôlé les facteurs démographiques, nous avons observé que la réalisation d’au moins une activité culturelle au cours de la vie impactait positivement les capacités d’inhibition, alors que la mise à jour était impactée négativement par un trop grand nombre de loisirs domestiques. Lorsqu’on considère les loisirs actuellement pratiqués, nous observons que la réalisation d’au moins un loisir social a un impact positif sur la flexibilité alors que deux activités à caractère social sont nécessaires pour avoir un impact positif sur la mise à jour. En conclusion, nous observons un effet mitigé et différencié de la réserve cognitive sur le déclin exécutif. [less ▲]

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See detailExploration des processus de recollection et de familiarité chez des patients présentant une plainte mnésique : une étude longitudinale
Simon, Jessica ULg; Collette, Fabienne ULg; SALMON, Eric ULg et al

Poster (2017, May 19)

Recollection refers to recall of details about past events, and familiarity is a feeling of oldness. In this study, we tested how recollection and familiarity are affected in patients with memory ... [more ▼]

Recollection refers to recall of details about past events, and familiarity is a feeling of oldness. In this study, we tested how recollection and familiarity are affected in patients with memory complaints compared to normal aging. We recruited 23 healthy older participants, 9 patients with subjective memory impairment (SCI) and 23 patients with mild cognitive impairment (MCI). Participants performed one 2-alternative forced-choice and one Yes-No recognition memory task including pictures and words, followed by a short neuropsychological evaluation. Fifteen healthy participants and 23 patients (9 SCI and 14 MCI) took part in a neuropsychological follow-up after a mean delay of 21 months. At inclusion, MCI patients had poorer performance in recognition than the other groups, which did not differ. MCI patients had worse performance regarding familiarity and recollection indexes compared to healthy controls and SCI, who exhibit similar performance. There was no interaction between groups and format or material. During the follow-up evaluation, five MCI returned to a normal level of efficiency and were considered as SCI. Based on the French adaptation of the free and cued selective reminding test (RLRI-16), we calculated cognitive decline curves in our patients. We observed that recollection and familiarity indexes were explained by the decline curves calculated on the number of freely recalled items. So, recollection and familiarity were used less efficiently in MCI than SCI although both groups complained about their memory. [less ▲]

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See detailAnosognosia for behavioral disorder is related to confidence for false self-related memories in Alzheimer’s disease
Mélon, Marlène; Collette, Fabienne ULg; Salmon, Eric ULg et al

Poster (2017, March 24)

Impaired self-awareness (i.e. anosognosia) and altered metacognitive monitoring in memory tasks have both been evidenced in AD. Furthermore, cognitive studies showed disrupted interaction between self and ... [more ▼]

Impaired self-awareness (i.e. anosognosia) and altered metacognitive monitoring in memory tasks have both been evidenced in AD. Furthermore, cognitive studies showed disrupted interaction between self and memory cognitive systems in AD, reducing cognitive advantages of self-related memories (i.e. decreasing self reference effect, SRE) in these patients. However, how anosognosia relates to impaired metacognitive monitoring in AD, particularly for self-related memories, is still an open question. To investigate this question, an ecological memory task based on face-name associations was administrated to 20 healthy older controls (HC) and 20 mild AD patients. The influence of self-reference at encoding was assessed on subsequent name recall and recollective experience, as well as on predictive (feeling-of-knowing, FOK) and postretrieval (judgments-of-confidence, JOC) metacognitive judgments on name recognition in all participants. Furthermore relationships between metacognitive outcomes and awareness of daily cognitive and behavioral impairment was examined in AD. Altered SRE was evidenced in name recall and recollective experience in AD. Patients also showed impaired FOK and JOC, as well as lower awareness of their daily functioning impairment (anosognosia). Nevertheless, differential effect of self on metacognitive judgment in AD and HC was only observed on JOC for false memories. Importantly, anosognosia for behavioral disorders was related to post-retrieval confidence for false recognition of self-related items in AD patients. Thus, anosognosia concerning behavioral disorder and altered post-retrieval monitoring of self-related memories appear to be related in AD. We hypothesized that impaired monitoring of personal false memories may lead AD patients to rely on distorted recent reality when providing judgment about their everyday behavioral functioning. [less ▲]

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See detailRelating pessimistic memory predictions to Alzheimer’s disease brain structure
Genon, Sarah ULg; Simon, Jessica ULg; Bahri, Mohamed Ali ULg et al

Poster (2017, March 23)

Patients with Alzheimer’s disease (AD) show impairment of episodic memory and related metacognitive processes. The present study examined subjective metacognitive judgments preceding objective memory ... [more ▼]

Patients with Alzheimer’s disease (AD) show impairment of episodic memory and related metacognitive processes. The present study examined subjective metacognitive judgments preceding objective memory retrieval and investigated the neural correlates of pessimistic predictions for successfully retrieved memories in AD patients. AD patients and healthy older participants provided predictive judgements on their recognition performance before retrieval of famous (semantic) and recently learned (episodic) names. Correlations between grey matter volume (GMV) in T1 images and behavioural scores were examined with multivariate (PLS) and univariate (GLM) analyses in AD patients. AD patients showed a significant proportion of successful name recognition preceded by pessimistic prediction (Prediction_low_hits) in episodic memory. PLS revealed that behavioural pattern in AD patients was related with a mainly right lateralized pattern of GMV decrease including medial temporal lobe and posterior cingulate cortex, but also right ventrolateral prefrontal cortex (VLPFC). GLM further confirmed that pessimistic prediction negatively correlated with GMV in VLPFC. Thus, impaired monitoring processes (possibly influenced by inaccurate beliefs) allowing inferences about one’s own memory performance are primarily related to decrease GMV in VLPFC in AD patients. [less ▲]

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See detailRecognition memory is associated with hippocampal volume in aging population: new evidence from brain imaging study
Narbutas, Justinas ULg; Blanpain, Manon ULg; Van Egroo, Maxime ULg et al

Poster (2017, March 23)

Introduction. The hippocampus is crucial for episodic memory, especially for recollection and pattern separation (i.e., the ability to store similar episodes as distinct memory traces). Episodic memory ... [more ▼]

Introduction. The hippocampus is crucial for episodic memory, especially for recollection and pattern separation (i.e., the ability to store similar episodes as distinct memory traces). Episodic memory declines with aging and this has been associated with hippocampal dysfunction. The main objective of our study was to explore how performance on a recognition memory task designed to assess pattern separation is associated with hippocampal volume in aging population. Methods. Fourteen healthy late middle-aged participants (52-69 years-old) were evaluated on a Mnemonic Similarity Task (MST). In this task, participants study pictures and then have to discriminate between targets, similar lures, and unrelated foil objects. Recognition memory (RM) is assessed as the difference between hits and false alarms to unrelated foils, while pattern separation Bias metric (BPS) is the difference between the rate of ‘‘Similar’’ responses given to the lure items minus ‘‘Similar’’ responses given to the foils. Hippocampal volume was calculated using ASHS software, which uses T1-weighted and T2-weighted MRI to obtain optimal segmentation of hippocampal subfields. Results. Correlation analysis of preliminary data revealed that RM was significantly positively associated with the volume of the left subiculum and left perirhinal area 35, while there were no significant correlations in the right hemisphere. BPS was positively correlated with the volume of right CA2 region, but negatively associated with the volume of right CA3 region, what is more contradictory according to the current literature. No significant link was found between BPS and the volume of hippocampal subfields in the left hemisphere. Conclusion. In a middle-aged population, better visual recognition memory is associated with larger volume of the left subiculum and perirhinal area 35, two regions supporting representation of objects [less ▲]

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See detailProcessus cognitifs et neurobiologiques sous-jacents aux déficits de mémoire épisodique dans la maladie d’Alzheimer
Collette, Fabienne ULg

Conference (2017)

Les troubles de la mémoire épisodique représentent une des caractéristiques majeures et précoces de la maladie d’Alzheimer. Ces difficultés sont classiquement attribuées à des déficits au niveau de ... [more ▼]

Les troubles de la mémoire épisodique représentent une des caractéristiques majeures et précoces de la maladie d’Alzheimer. Ces difficultés sont classiquement attribuées à des déficits au niveau de l’encodage et de la consolidation de l’information, processus dépendant notamment des régions temporales internes (et plus particulièrement de l’hippocampe) qui sont atteintes très tôt dans le décours de la maladie. Un certain nombre de données récentes ont toutefois amené à raffiner cette conceptualisation initiale. Il est en effet progressivement apparu que des processus très spécifiques sous-tendent la performance aux tâches de mémoire épisodique utilisées en clinique pour le diagnostic de la maladie, tels que la capacité à créer des liens associatifs entre les items ou à créer des représentations mnésiques très distinctives, ou encore la capacité à faire appel à des processus auto-référentiels. L’efficacité de ces processus semble par ailleurs affectée de façon relativement sélective par différents processus neuropathologiques tels que l’atrophie de certaines régions hippocampiques, la diminution de l’épaisseur corticale, la déconnexion entre réseaux cérébraux, la charge amyloide, ou même la présence de facteurs plus subjectifs tels qu’une plainte mnésique. Les troubles de mémoire épisodique associés à la maladie d’Alzheimer semblent donc clairement multidéterminés. En lien avec ces données cognitives et neurobiologiques, nous discuterons également brièvement l’intérêt des classifications actuelles des troubles cognitifs associés au vieillissement pour comprendre le fonctionnement mnésique et ses bases cérébrales. [less ▲]

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See detailAnosognosie et monitoring des souvenirs associés au « soi » dans la Maladie d’Alzheimer
Genon, Sarah ULg; Mélon, Marlène; Collette, Fabienne ULg et al

Conference (2017)

Chez les patients atteints de maladie d’Alzheimer (MA), on observe dès les stades débutants d’une part un phénomène d’anosognosie, qui peut être considéré comme une altération de la conscience de soi, et ... [more ▼]

Chez les patients atteints de maladie d’Alzheimer (MA), on observe dès les stades débutants d’une part un phénomène d’anosognosie, qui peut être considéré comme une altération de la conscience de soi, et d’autre part un dysfonctionnement des processus de monitoring mnésique [1]. En outre, l’interaction entre le soi et la mémoire (conférant un bénéfice mnésique pour les informations associées à soi), apparaît significativement altérée dans la MA. Dans la présente étude, nous avons examiné les relations entre l’anosognosie et le monitoring lors de la récupération en mémoire d’informations expérimentalement associées à soi. Nous avons évalué les processus de monitoring lors de la récupération en mémoire à l’aide d’une tâche expérimentale de 32 paires visage-prénom, ainsi que l’anosognosie à l’aide du questionnaire d’anosognosie dans la démence (AQD, [2]) chez 20 patients MA et 20 personnes âgées contrôles (AC). Durant la phase d’encodage, les paires visage-prénom ont été présentées aux participants soit comme des personnes faisant partie de leur famille (soi) soit comme des personnes faisant partie de la famille de l’expérimentateur (autrui). Ensuite, nous avons évalué les jugements de « sentiment de savoir » (FOK), les performances de rappel et de reconnaissance, ainsi que les jugements de confiance (JOC) des participants pour le nom de chaque personne lorsque son visage était présenté. Nos résultats ont confirmé l’altération de la conscience de soi (c’est-à-dire l’anosognosie mesurée par l’AQD), l’altération du bénéfice mnésique pour les informations associées à soi, ainsi que l’altération des processus de monitoring lors de la récupération en mémoire (FOK et JOC) chez les patients MA. Néanmoins, une modification de l’interaction entre le soi et les processus de monitoring chez ces patients a été observée uniquement au niveau des sentiments de confiance pour des souvenirs erronés. Nous avons également observé que l’anosognosie des troubles comportementaux était significativement corrélée à la proportion de sentiments de confiance pour des reconnaissances erronées sur les items associés à soi. En conclusion, notre étude suggère que l’altération de la conscience des troubles comportementaux chez les patients MA pourrait être liée à un déficit de monitoring des souvenirs liés à soi. C’est-à-dire que la conscience altérée du dysfonctionnement au quotidien pourrait s’appuyer sur des souvenirs personnels déformés. [less ▲]

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See detailThe neural bases of proactive and reactive control processes in normal aging
Manard, Marine ULg; François, Sarah ULg; Phillips, Christophe ULg et al

in Behavioural Brain Research (2017), 320

Introduction. Research on cognitive control suggests an age-related decline in proactive control abilities (anticipatory control), whereas reactive control (following conflict detection) seems to remain ... [more ▼]

Introduction. Research on cognitive control suggests an age-related decline in proactive control abilities (anticipatory control), whereas reactive control (following conflict detection) seems to remain intact. As proactive and reactive control abilities are associated with specific brain networks, this study investigated age-related effects on the neural substrates associated with each kind of control. Methods. In an event-related fMRI study, a modified version of the Stroop task was administered to groups of 20 young and 20 older healthy adults. Based on the theory of dual mechanisms of control, the Stroop task has been built to induce proactive or reactive control depending on task context. Results. Behavioral results (p < .05) indicated faster processing of interfering items in the mostly incongruent (MI) than the mostly congruent (MC) context in both young and older participants. fMRI results showed that reactive control is associated with increased activity in left frontal areas for older participants. For proactive control, decreased activity in the bilateral anterior cingulate cortex was associated with more activity in the right middle frontal gyrus in the older than the younger group. Conclusion. These observations support the hypothesis that aging affects the neural networks associated with reactive and proactive cognitive control differentially. These age-related changes are very similar to those observed in young adults with low dopamine availability, suggesting that a general mechanism (prefrontal dopamine availability) may modulate brain networks associated with various kinds of cognitive control. [less ▲]

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See detailRelating pessimistic memory predictions to Alzheimer’s disease brain structure
Genon, Sarah ULg; Simon, Jessica ULg; Bahri, Mohamed Ali ULg et al

in Cortex : A Journal Devoted to the Study of the Nervous System & Behavior (2016), 85

Patients with Alzheimer’s disease (AD) show impairment of episodic memory and related metacognitive processes. The present study examined subjective metacognitive judgments preceding objective memory ... [more ▼]

Patients with Alzheimer’s disease (AD) show impairment of episodic memory and related metacognitive processes. The present study examined subjective metacognitive judgments preceding objective memory retrieval and investigated the neural correlates of pessimistic predictions for successfully retrieved memories in AD patients. AD patients and healthy older participants provided predictive judgements on their recognition performance before retrieval of famous (semantic) and recently learned (episodic) names. Correlations between grey matter volume (GMV) in T1 images and behavioural scores were examined with multivariate (PLS) and univariate (GLM) analyses in AD patients. AD patients showed a significant proportion of successful name recognition preceded by pessimistic prediction (Prediction_low_hits) in episodic memory. PLS revealed that behavioural pattern in AD patients was related with a mainly right lateralized pattern of GMV decrease including medial temporal lobe and posterior cingulate cortex, but also right ventrolateral prefrontal cortex (VLPFC). GLM further confirmed that pessimistic prediction negatively correlated with GMV in VLPFC. Thus, impaired monitoring processes (possibly influenced by inaccurate beliefs) allowing inferences about one’s own memory performance are primarily related to decrease GMV in VLPFC in AD patients. [less ▲]

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See detailThe influence of COMT on the neural substrates of short-term memory in normal aging
Manard, Marine ULg; Salmon, Eric ULg; Collette, Fabienne ULg

Conference (2016, September 02)

Working memory dopaminergic modulation is generally expressed in healthy aging by an advantage for carriers of the Met allele at behavioral and brain activity levels. However, most tasks used did not ... [more ▼]

Working memory dopaminergic modulation is generally expressed in healthy aging by an advantage for carriers of the Met allele at behavioral and brain activity levels. However, most tasks used did not allow to easily disentangle the contribution of maintenance and manipulation processes. We explored the effect of COMT genotype on the maintenance process using a Sternberg memory task varying the amount of information presented, in young and older homozygous carriers for the Val and Met alleles of the COMT gene. Although no clear behavioral difference was observed between groups, patterns of cerebral activity indicate difficulties for Met older individuals to maintain stable representations. These results will be discussed in terms of dopaminergic contribution to stability/flexibility of cognitive processes during aging. [less ▲]

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See detailAge-related changes in the modulation of attentional brain responses to sleep pressure at night
Schmidt, Christina ULg; Reichert, Carolin; Maire, Micheline et al

in Journal of Sleep Research (2016, September)

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See detailAge-related differences in the dynamics of cortical excitability and cognitive inhibition during prolongedwakefulness
Gaggioni, Giulia ULg; Chelllappa, S.; Ly, J. et al

Conference (2016, September)

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See detailLocal modulation of human brain responses by circadian rhythmicity and sleep debt
Muto, Vincenzo ULg; Jaspar, Mathieu ULg; Meyer, Christelle et al

in Science (2016), 351(6300),

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See detailEffects of aging on task- and stimulus-related cerebral attention networks
Kurth, Sophie ULg; Majerus, Steve ULg; Bastin, Christine ULg et al

in Neurobiology of Aging (2016), 44

Interactions between a dorsal attention (DAN) and a ventral attention cerebral network (VAN) have been reported in young participants during attention or short term memory (STM) tasks. Since it remains an ... [more ▼]

Interactions between a dorsal attention (DAN) and a ventral attention cerebral network (VAN) have been reported in young participants during attention or short term memory (STM) tasks. Since it remains an under-investigated question, age effects on DAN and VAN activity and their functional balance were explored during performance of a STM task. Older and young groups showed similar behavioral patterns of results. At the cerebral level, DAN activation increased as a function of increasing STM load in both groups, suggesting preserved activity in DAN during healthy aging. Age-related over-recruitment in regions of the DAN in the higher task load raised the question of compensation attempt versus less efficient use of neural resources in older adults. Lesser decrease of VAN activation with increasing load and decreased stimulus-driven activation in the VAN, especially in the higher load, in older participants suggested age-related reduced response in the VAN. However, functional connectivity measures showed that VAN was still functionally connected to the DAN in older participants. [less ▲]

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See detailThe influence of COMT on the neural substrates of short-term memory in normal aging
Collette, Fabienne ULg; Manard, Marine ULg; Salmon, Eric ULg

Conference (2016, July 21)

Working memory dopaminergic modulation is generally expressed in healthy aging by an advantage for carriers of the Met allele at behavioral and brain activity levels. However, most tasks used did not ... [more ▼]

Working memory dopaminergic modulation is generally expressed in healthy aging by an advantage for carriers of the Met allele at behavioral and brain activity levels. However, most tasks used did not allow to easily disentangle the contribution of maintenance and manipulation processes. We explored the effect of COMT genotype on the maintenance process using a Sternberg memory task varying the amount of information presented, in young and older homozygous carriers for the Val and Met alleles of the COMT gene. Although no clear behavioral difference was observed between groups, patterns of cerebral activity indicate difficulties for Met older individuals to maintain stable representations. These results will be discussed in terms of dopaminergic contribution to stability/flexibility of cognitive processes during aging. [less ▲]

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See detailDisrupted interaction between self and memory in patients with Alzheimer’s disease
Genon, Sarah ULg; Salmon, Eric ULg; Collette, Fabienne ULg et al

Conference (2016, July)

In humans, self and memory processes interact as evidenced by the self reference (SRE) and self reference recollection effects (SRRE). However, in patients with Alzheimer’s disease (AD), this relationship ... [more ▼]

In humans, self and memory processes interact as evidenced by the self reference (SRE) and self reference recollection effects (SRRE). However, in patients with Alzheimer’s disease (AD), this relationship can be disrupted. This was evidenced by impaired SRE and SRRE in AD for recognition of adjectives previously judged for self-relevance, as well as recall of names of people previously linked to the self. For both materials, a qualitative impairment of the recollective experience for the self-related items was also observed in AD. A neuroimaging approach suggested that reduced SRE is related to decreased grey matter volume in the lateral prefrontal cortex (lPFC). Thus, retrieval of recent self-related memories is impaired in relation to altered high-order processes in lPFC in AD. [less ▲]

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See detailSeasonal variation in human COGNITIVE brain responses
Meyer, Christelle; Muto, Vincenzo ULg; Jaspar, Mathieu ULg et al

Poster (2016, June)

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See detailSubstrats neuronaux de l'encodage non réussi dans le vieillissement
François, Sarah ULg; Angel, Lucie; Salmon, Eric ULg et al

Conference (2016, May 27)

Objectifs En utilisant l'IRM fonctionnelle, nous nous sommes intéressés à l'effet de l'âge sur les substrats neuronaux de l'encodage non réussi – l'activation à l'encodage pour les items oubliés par la ... [more ▼]

Objectifs En utilisant l'IRM fonctionnelle, nous nous sommes intéressés à l'effet de l'âge sur les substrats neuronaux de l'encodage non réussi – l'activation à l'encodage pour les items oubliés par la suite. Méthodologie Dans un scanner IRM, nous avons soumis des volontaires (20 jeunes et 19 âgés) à une tâche de mémoire épisodique avec consignes d'encodage incident. Durant celle-ci, des dessins d'objets en noir et blanc leur étaient présentés. Il leur était demandé d'effectuer un jugement de taille sur ces objets. Ensuite, toujours dans le scanner, les objets de la phase d'encodage ainsi que de nouveaux objets leurs étaient présentés afin d'évaluer leur reconnaissance de ceux-ci. Pour ce faire, les volontaires effectuaient un jugement de Recollection/Familiarité/Nouveauté. Résultats Les résultats comportementaux montrent une recollection altérée mais une familiarité préservée chez nos volontaires âgés. L'analyse des résultats IRM a été effectuée selon un design évènementiel (SPM8), dans lequel nous avons comparé les aires cérébrales activées à l'encodage pour les items qui n'ont pas été reconnus ultérieurement et pour ceux qui ont donné lieu à un jugement de recollection (p<.001 non-corrigé). Dans les deux groupes, un pattern d'activation correspondant au réseau du mode par défaut (RMD). Chez les volontaires âgés, les résultats ont également mis en évidence une activation supplémentaire du réseau attentionnel fronto-pariétal. Ensuite, le contraste entre les activations pour les items qui n'ont pas été reconnus ultérieurement et ceux qui ont donné lieu à un jugement de familiarité a aussi mis en évidence des régions du RMD, mais dans une moindre mesure. En effet, les activités communes aux deux groupes d'âge n'ont montré qu'une activation du précuneus. Discussion Comparé à la recollection, l'oubli d'informations semble associé, à l'encodage, à un recrutement accru du RMD qui pourrait refléter une incapacité à mettre en place des processus d'encodage efficaces, à la fois chez les jeunes adultes et les adultes plus âgés. De plus, l'activation supplémentaire du réseau fronto-pariétal chez ces derniers pourrait indiquer un fonctionnement moins différencié des réseaux cérébraux associés à l'encodage en mémoire. Lorsque l'on compare l'oubli d'informations à la familiarité, l'activation moindre du RMD pourrait suggérer qu'un certain niveau d'activation du RMD (et donc la présence de pensées étrangères à la tâche) n'empêche pas forcément toute reconnaissance sur base d'un sentiment de familiarité. [less ▲]

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