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 detailExecutive functions in normal aging: the mediating effect of processing speed and attentional system
Gilsoul, Jessica ULg; Simon, Jessica ULg; Collette, Fabienne ULg

Poster (2017, September 14)

Objective The normal aging is associated with decrease in executive functioning efficiency. However, the source of these cognitive difficulties could reside in some factors that are not executive per se ... [more ▼]

Objective The normal aging is associated with decrease in executive functioning efficiency. However, the source of these cognitive difficulties could reside in some factors that are not executive per se. Therefore, this present study is aimed at determining whether speed of processing and attentional variables would mediate the effect of age on the executive functioning. Participants and Methods Young (n = 104) and old (n = 63) participants were enrolled and carried out a large battery made of 21 executive (inhibition, shifting, working memory updating, and double task coordination), attentional (phasic alertness, selective attention, and sustained attention), and processing speed tasks. Based on Baron & Kenny’s recommendations (1986), mediation models of the age effect on the executive functioning were carried out with processing speed and attentional system taken as mediators. Results Selective attention significantly mediated the effect of age on working memory updating [􀇻R2 = 7%, p < .001]. Moreover, processing speed significantly mediated the effect of age on shifting [􀇻R2 = 7%, p < .001], working memory updating [􀇻R2 = 5%, p < .001], and double task coordination [􀇻R2 = 14%, p < .001]. Conclusions The mediating effect of age on most of the executive functions by measures of processing speed is in agreement with the literature showing a major influence of the slowdown of the processing speed on cognition (Salthouse, 1992; 2000; 2005). The age effect on inhibition did not seem to be mediated neither by the attentional variables nor the speed variables, which is in accordance with Zacks & Hasher’s hypothesis (1988). According to these authors, inhibition would be the first cognitive function to decline with age. [less ▲]

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See detailNon-pathological aging of the executive functions: influence of the Val108/158Met nucleotide polymorphism of the COMT gene
Gilsoul, Jessica ULg; Manard, Marine ULg; Collette, Fabienne ULg

Poster (2017, July 13)

Objectives. The aim of the study is to investigate the influence of the COMT Val108/158Met nucleotide polymorphism, associated with dopaminergic regulation, on executive functions in normal aging. Indeed ... [more ▼]

Objectives. The aim of the study is to investigate the influence of the COMT Val108/158Met nucleotide polymorphism, associated with dopaminergic regulation, on executive functions in normal aging. Indeed, according to the Dual-State Theory, Val/Val polymorphism of the COMT gene would favor better flexibility abilities, whereas Met/Met carriers would favor better stability abilities. These genotypic effects should be magnified in older people, as a decrease in cognitive resources increases the influence of individual genetic differences on cognitive performance. Method. We assessed the executive processes of inhibition, shifting, and updating – thanks to many different tasks in groups of young (n = 55) and aged participants (n = 45) carrying one of the three polymorphism of the COMT gene (Val/Val, Val/Met, Met/Met). T-tests between our two groups (Young versus Aged) but also a 6 (Group: Young-Met/Met, Young-Val/Met, Young- Val/Val, Old-Met/Met, Old-Val/Met, and Old-Val/Val) X 3 (Executive functioning: Inhibition, Shifting, and Updating) repeated measure ANOVA with Executive functioning as within-subject factor (p < .05) were carried out. Results. Young and old participants significantly differed on the three executive functions. The comparison of genotypic groups showed no significant differences in young or older participants respectively. Interestingly, the Old-Val/Val group showed a lower performance than the young one on inhibition tasks. Conclusion. As expected, we found an age effect on all the executive functions. The significant difference between the Young-Val/Val and the Old-Val/Val groups on inhibition suggests an age-related decrease in abilities requiring a stability component in individuals possessing a less favoring genotype for this component. [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, June 01)

Les données actuelles suggèrent une altération précoce de la recollection dans les premiers stades de la maladie d’Alzheimer. Par contre, aucun consensus n’a pu être dégagé concernant l’intégrité de la ... [more ▼]

Les données actuelles suggèrent une altération précoce de la recollection dans les premiers stades de la maladie d’Alzheimer. Par contre, aucun consensus n’a pu être dégagé concernant l’intégrité de la familiarité. En effet, certaines études suggèrent une altération précoce de ce processus, alors que d’autres montrent une préservation de celle-ci. Dans ce cadre, nous avons exploré l'impact du type de format de reconnaissance et du matériel sur la recollection et la familiarité chez des patients qui se plaignent de leur mémoire. Nous avons recruté 23 participants âgés contrôles, 9 patients présentant un trouble subjectif de la mémoire (SCI) et 23 patients présentant un trouble cognitif léger (TCL). Les participants ont réalisé une tâche de reconnaissance à choix forcé à deux alternatives et une tâche de reconnaissance Oui-Non incluant des images et des mots. Ces tâches étaient suivies d’une courte évaluation neuropsychologique. Quinze participants âgés contrôles et 23 patients ont participé au suivi, incluant une évaluation neuropsychologique, dans un délai moyen de 21 mois. Nos résultats montrent qu’à l’inclusion, les patients avec TCL avaient des performances moindres en reconnaissance que les deux autres groupes, qui ne différaient pas. De même, ces patients utilisaient moins efficacement la recollection et la familiarité par rapport aux contrôles et aux SCI, qui présentaient des performances similaires. Il n’y avait aucune interaction entre le groupe et le type de format ou le matériel. Lors du suivi, cinq patients avec TCL ont retrouvé un niveau d’efficience cognitive dans la norme et ont été considérés comme des SCI car les plaintes mnésiques étaient toujours présentes. Sur la base de l'adaptation française du test de rappel libre et indicé (RLRI-16), nous avons calculé une pente de déclin mnésique pour chacun de nos patients. Nous avons observé que les indices de recollection et de familiarité étaient expliqués par les pentes de déclin calculées sur le nombre total d’items rappelés librement. Ainsi, nous avons observé un déclin de la recollection et la familiarité dans le groupe de TCL mais pas dans celui des SCI, bien que les deux groupes se plaignent de leur mémoire. En outre, l'efficacité de la familiarité pourrait prédire un déclin cognitif futur. [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, May 31)

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. Method. 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. BPS was positively correlated with the volume of right CA2 region, but negatively associated with the volume of right CA3 region. Discussion. In a late 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 detailNON-PATHOLOGICAL AGING OF THE EXECUTIVE FUNCTIONS: INFLUENCE OF THE VAL108/158MET NUCLEOTIDE POLYMORPHISM OF THE COMT GENE
Gilsoul, Jessica ULg; Manard, Marine ULg; Collette, Fabienne ULg

Conference (2017, May 31)

Introduction. According to the Dual-State Theory of prefrontal cortex dopamine, Val/Val polymorphism of the COMT gene would favor better flexibility abilities, whereas Met/Met carriers would favor better ... [more ▼]

Introduction. According to the Dual-State Theory of prefrontal cortex dopamine, Val/Val polymorphism of the COMT gene would favor better flexibility abilities, whereas Met/Met carriers would favor better stability abilities. These genotypic effects should be magnified in older people, as a decrease in cognitive resources increases the influence of individual genetic differences on cognitive performance. Therefore, the aim of the study is to investigate the influence of the COMT Val108/158Met nucleotide polymorphism on executive functions in normal aging. Method. We assessed the executive processes of inhibition, shifting, and updating thanks to many different tasks in groups of young (n = 55) and aged participants (n = 45) carrying one of the three polymorphisms of the COMT gene (Val/Val, Val/Met, Met/Met). T-tests between our two groups (Young versus Aged) but also a 6 (Group: Young-Met/Met, Young-Val/Met, Young-Val/Val, Old-Met/Met, Old-Val/Met, and Old-Val/Val) X 3 (Executive functioning: Inhibition, Shifting, and Updating) repeated measure ANOVA with Executive functioning as within-subject factor (p < .05) were carried out. Results. Young and old participants significantly differed on the three executive functions. The comparison of genotypic groups showed no significant differences in young or older participants respectively. Interestingly, the Old-Val/Val group showed a lower performance than the young one on inhibition tasks. Discussion. As expected, we found an age effect on all the executive functions. The significant difference between the Young-Val/Val and the Old-Val/Val groups on inhibition suggests an age-related decrease in abilities requiring a stability component in individuals possessing a less favoring genotype for this component. [less ▲]

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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 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, May 19)

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. Method. 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. BPS was positively correlated with the volume of right CA2 region, but negatively associated with the volume of right CA3 region. Discussion. In a late 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 detailAssociation entre régulation circadienne du cycle de veille-sommeil et performance de mémoire de travail chez les personnes âgées
Schmidt, Christina ULg; Reichert, Carolin Franziska; Maire, Micheline et al

Poster (2017, May 19)

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See detailVieillissement non pathologique des fonctions exécutives : influence du polymorphisme nucléotidique val108/158met du gène COMT
Gilsoul, Jessica ULg; Manard, Marine ULg; Collette, Fabienne ULg

Poster (2017, May 19)

Introduction. Selon la Théorie des États-Duaux, les homozygotes Val sur le gène COMT possèderaient de meilleures capacités de flexibilité tandis que les individus Met/Met favoriseraient les capacités de ... [more ▼]

Introduction. Selon la Théorie des États-Duaux, les homozygotes Val sur le gène COMT possèderaient de meilleures capacités de flexibilité tandis que les individus Met/Met favoriseraient les capacités de stabilité. Ces effets génotypiques seraient amplifiés dans le vieillissement car la diminution des ressources cérébrales augmente l’influence des différences génétiques sur la cognition. Notre but est d’investiguer l’influence du polymorphisme nucléotidique COMTVal108/158Met sur les fonctions exécutives dans le vieillissement normal. Méthode. Trois fonctions exécutives ont été évaluées grâce à différentes tâches chez des participants jeunes (N=55) et âgés (N=45) portant l’un des génotypes du gène COMT (Val/Val, Val/Met, et Met/Met). Nous avons réalisé des tests t entre les deux groupes ainsi qu’une ANOVA 6 (Groupe : Jeunes-Met/Met, Jeunes-Val/Met, Jeunes -Val/Val, Âgés-Met/Met, Âgés-Val/Met, et Âgés-Val/Val) X 3 (Fonctionnement exécutif : Inhibition, Flexibilité, et Mise à jour) à mesures répétées avec le Fonctionnement exécutif comme facteur intra-sujet (p < ,05). Résultats. Jeunes et âgés différaient significativement sur les trois fonctions exécutives. Au sein des groupes jeunes et âgés, aucune différence significative n’a pu être mise en évidence entre les groupes génotypiques. De façon intéressante, le groupe des Âgés-Val/Val avait de plus faibles performances que le groupe des Jeunes-Val/Val en inhibition. Discussion. Comme attendu, nous avons trouvé un effet de l’âge sur toutes les fonctions exécutives. La différence entre les Jeunes-Val/Val et les Âgés-Val/Val en inhibition soutient l’idée d’une diminution avec l’avancée en âge des performances lorsqu’une composante de stabilité est requise par la tâche chez des individus possédant un génotype moins favorable pour cette composante. [less ▲]

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See detailLe fonctionnement exécutif dans le vieillissement normal : l’effet médiateur de la vitesse de traitement et du système attentionnel
Gilsoul, Jessica ULg; Simon, Jessica ULg; Collette, Fabienne ULg

Poster (2017, May 19)

Introduction. Le vieillissement normal est associé à une diminution d’efficacité des fonctions exécutives. Cependant, la source de ces difficultés pourrait résider dans certains facteurs « non exécutifs » ... [more ▼]

Introduction. Le vieillissement normal est associé à une diminution d’efficacité des fonctions exécutives. Cependant, la source de ces difficultés pourrait résider dans certains facteurs « non exécutifs ». Dès lors, cette étude a pour but de déterminer si la vitesse de traitement et les variables attentionnelles pourraient médier l’effet de l’âge sur le fonctionnement exécutif. Méthode. Des participants jeunes (N = 104) et âgés (N = 63) ont réalisé une batterie de 21 tâches exécutives (inhibition, flexibilité, mise à jour, et coordination de double tâches), attentionnelles (alerte phasique, attention sélective, et attention soutenue), et de vitesse de traitement. Des modèles de médiation avec la vitesse de traitement et le fonctionnement attentionnel pris séparément comme médiateurs ont été réalisés. Résultats. L’attention sélective médie significativement l’effet de l’âge sur la mise à jour [ΔR2 = 7%, p < ,001]. De plus, la vitesse de traitement médie significativement l’effet de l’âge sur la flexibilité [ΔR2 = 7%, p < ,001], la mise à jour [ΔR2 = 5%, p < ,001], et la coordination de double tâches [ΔR2 = 14%, p < ,001].Discussion. La médiation de l’effet de l’âge sur la plupart des fonctions exécutives par les mesures de vitesse est en accord avec la littérature montrant une grande influence d’un ralentissement de la vitesse de traitement sur la cognition. L’effet de l’âge sur l’inhibition ne semble médié par aucune des variables attentionnelles et de vitesse, ce qui est en accord avec l’hypothèse selon laquelle l’inhibition serait la première fonction cognitive à décliner avec l’avancée en âge (Zacks & Hasher,1988). [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 detailCerebral correlates underlying the impact of circadian and sleep homeostatic processes on cognition
Schmidt, Christina ULg; Reichert, Carolin; Maire, Micheline et al

Conference (2017, May 11)

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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 detailNeural correlates of subsequent recollection and familiarity in ageing
François, Sarah ULg; Angel, Lucie; Salmon, Eric ULg et al

Poster (2017, March)

It is now commonly accepted that, in ageing, recollection processes are impaired and familiarity seems to be relatively preserved. In this study, we were interested in the differences between younger and ... [more ▼]

It is now commonly accepted that, in ageing, recollection processes are impaired and familiarity seems to be relatively preserved. In this study, we were interested in the differences between younger and older participants regarding cerebral activity during encoding depending on whether the item later elicited recollection or familiarity. Twenty young volunteers and 19 older volunteers were presented visual stimuli depicting objects. After a first fMRI session in which the items were encoded, they underwent a recognition memory task in which they judged whether items were Remembered, Familiar or New. Data were analysed using SPM8, with an event-related design comparing modifications in cerebral activity between the two subjects groups during encoding (1) for the items leading to recollection compared to those leading to familiarity, and (2) for the items associated with familiarity compared to those which were not recognized. Results showed that older adults displayed a heightened activity in regions of the default-mode network for subsequent recollection. As it does not appear to be deleterious, it could stem from a more frequent use of self-referential appraisal as an encoding strategy in older adults. Furthermore, they show supplementary contralateral activations in frontal and temporal regions, which could be indicative of dedifferentiation or attempted compensation. To conclude, it appears that despite relying less on elaborative encoding, older adults seem to be able to perform recollection using qualitatively different strategies than young adults. [less ▲]

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