References of "Bastin, Christine"
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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 detailSemantic relatedness of the memoranda prevents older adults from benefitting from unitization
Delhaye, Emma ULg; Tibon, Roni; Gronau, Nurit et al

Poster (2016)

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See detailImpact du format du test sur la recollection et la familiarité dans le vieillissement normal et le trouble cognitif léger de type amnésique
Simon, Jessica ULg; Gilsoul, Jessica ULg; SALMON, Eric ULg et al

Conference (2015, December 04)

Les tâches de reconnaissance à choix-forcé et oui/non ont largement été utilisées dans l’évaluation de la mémoire. Selon Norman et O’Reilly (2003), le format oui/non ferait davantage intervenir la ... [more ▼]

Les tâches de reconnaissance à choix-forcé et oui/non ont largement été utilisées dans l’évaluation de la mémoire. Selon Norman et O’Reilly (2003), le format oui/non ferait davantage intervenir la recollection alors que le format à choix-forcé favoriserait la comparaison du sentiment de familiarité associé à chaque item et la sélection du plus familier. L’objectif de cette étude est d’explorer l’impact du format du test sur la recollection et la familiarité au travers du vieillissement normal et pathologique. Septante participants jeunes (18 - 30 ans), 65 participants jeunes-âgés (55 - 69 ans), 53 participants âgés-âgés (70-85 ans) et 13 patients présentant un trouble cognitif léger amnésique (55-82 ans) ont réalisé deux tâches de reconnaissance. Pour chaque tâche, lors de l’encodage, nous avons présenté, à deux reprises, 25 images à mémoriser. Dans la tâche de reconnaissance à choix forcé, les participants devaient reconnaitre parmi trois images très semblables celle qui a été vue précédemment. Dans la tâche de reconnaissance oui/non, les items étaient présentés successivement et les participants devaient reconnaitre ceux présentés à l’encodage. Pour chaque item reconnu, les participants devaient fournir un jugement Remember/Know/Guess. Les ANOVA Groupe x Format à mesures répétées sur la dernière variable (p<0,05) ont révélé que les jeunes avaient de meilleures performances en reconnaissance (score d’) que les jeunes-âgés, qui ont eux-mêmes de meilleures performances que les âgés-âgés et les patients. En outre, les jeunes utilisent plus souvent le sentiment de familiarité pour reconnaître les images étudiées que les participants âgés et les patients. De plus, les participants jeunes-âgés utilisent plus souvent la familiarité que les participants âgés-âgés, alors qu’il n’y a pas de différence entre ceux-ci et les patients. Cependant, les fausses alarmes associées à la familiarité augmentent progressivement dans le vieillissement et la pathologie. L’utilisation de la recollection est progressivement réduite avec l’âge et altérée dans la pathologie. Enfin, les jeunes tendent à utiliser plus souvent la recollection dans la tâche à choix-forcé (p=0,055), alors qu’il n’y a pas de différence pour les autres groupes. Tous ces résultats suggèrent que le vieillissement normal s’accompagne d’un déclin progressif de la recollection et de la familiarité. Dans le vieillissement pathologique, on observe des performances similaires au groupe le plus âgé en reconnaissance malgré un déficit de recollection. Les patients utilisent la familiarité autant que les deux groupes âgés bien que les taux de fausses alarmes soient plus importants, suggérant une utilisation privilégiée mais inadéquate de ce processus. [less ▲]

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See detailLa détection précoce de la maladie d'Alzheimer
Bastin, Christine ULg

Conference (2015, November 17)

Lorsque le diagnostic de maladie d’Alzheimer est posé, les atteintes au niveau du cerveau et l’ampleur des difficultés dans la vie quotidienne ont atteint un seuil critique. Actuellement, les chercheurs ... [more ▼]

Lorsque le diagnostic de maladie d’Alzheimer est posé, les atteintes au niveau du cerveau et l’ampleur des difficultés dans la vie quotidienne ont atteint un seuil critique. Actuellement, les chercheurs et les cliniciens pensent que pour tenter de retarder l’apparition d’une démence, voire même l’empêcher, il faut agir bien avant que les premiers symptômes majeurs apparaissent. Le défi actuel est de trouver les meilleurs outils permettant de détecter le plus tôt possible les premiers signes de la maladie. Etant donné que des changements cognitifs peuvent être détectés très tôt, les neuropsychologues tentent d’identifier parmi les tests qui forment le bilan neuropsychologique ceux qui permettent de prédire au mieux le développement futur d’une maladie d’Alzheimer. Les recherches ont suggéré que les mesures ayant le meilleur pouvoir de prédiction semblent être celles de mémoire épisodique (qui est la capacité à se souvenir d’événements vécus dans un contexte bien précis) et les mesures de fluence verbale (qui est la capacité à citer un grand nombre de mots appartenant à une catégorie ou commençant par une lettre donnée). Le groupe Vieillissement et Mémoire, au sein du Centre de Recherches du Cyclotron (Université de Liège), poursuit actuellement deux lignes de recherche en lien avec la question de la détection précoce de la maladie d’Alzheimer : Premièrement, nous tentons de déterminer si nous pouvons encore mieux détecter les personnes à risque de développer une maladie d’Alzheimer en affinant les mesures de la mémoire. Le point de départ de cette recherche doit être une compréhension approfondie des mécanismes qui régissent le fonctionnement de la mémoire ainsi que de leurs bases cérébrales. Nos premiers résultats ont montré une perte précoce de la capacité à réactiver tous les détails d’un épisode vécu, associée à une déconnexion entre les régions d’un réseau cérébral incluant le cortex cingulaire postérieur et l’hippocampe. Deuxièmement, nous étudions les facteurs protecteurs qui permettent à certaines personnes de mieux résister que d’autres aux effets négatifs du vieillissement et de la pathologie cérébrale. Une étude non encore publiée menée auprès de personnes âgées sans trouble cognitif a montré que plus les personnes avaient étudié longtemps et avaient pratiqué une activité physique au cours de leur vie, meilleure était leur capacité à se souvenir des détails des événements vécus. Enfin, une approche idéale pour Identifier le plus tôt possible qui risque de développer des symptômes de déclin cognitif est l’approche multidisciplinaire. Plutôt que d’évaluer l’intérêt d’une mesure seule, nous proposons de tenir compte de manière combinée des différents éléments qui semblent contribuer à la détection précoce de la maladie d’Alzheimer : modifications neuropathologiques, mesures neuropsychologiques, mesures de la structure et du fonctionnement cérébral, habitudes de vie, changements physiologiques et modification du sommeil. [less ▲]

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See detailThe impact of ageing on episodic memory encoding: an fMRI study
François, Sarah ULg; Angel, Lucie; SALMON, Eric ULg et al

Poster (2015, September 04)

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See detailMesures de mémoire épisodique
Bastin, Christine ULg

Scientific conference (2015, June 09)

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See detailThe effect of ageing and encoding instructions on episodic memory
Hagelstein, Catherine ULg; François, Sarah ULg; Manard, Marine ULg et al

Poster (2015, May 28)

During ageing, a decline in episodic memory is observed, characterized by decreased recollection (a). In this study, we investigated the influence of encoding instructions, intentional or incidental, on ... [more ▼]

During ageing, a decline in episodic memory is observed, characterized by decreased recollection (a). In this study, we investigated the influence of encoding instructions, intentional or incidental, on the performance of younger and older adults during an episodic memory task. Twenty young volunteers (aged 18 to 30 years old) and 20 older volunteers (aged 61 to 72 years old) participated in this experiment. The stimuli consisted of 300 black-and-white drawings of common objects. The task comprised two steps. During the encoding phase, 100 items were presented once ("hard" condition) and 100 other items were presented twice ("easy" condition). During recognition, the items from the encoding phase were presented again, as well as 100 new items. In each age group, half of the participants received incidental encoding instructions (they had to make size judgements about the objects depicted) while the other half were explicitly asked to memorize the objects presented because they would be asked to recognize them later on (intentional encoding). During recognition, they performed a Remember-Know judgement for the items they believed they had seen earlier. We carried out ANOVAs in order to test for the influence of instructions, age group and number of repetitions of the items in one hand on the percentage of recollection and on the other hand on the percentage of familiarity (p<.05). Results show a significant effect of age, with more correct recollection responses in young adults, whereas more correct familiarity was found in older adults. Furthermore, it was found that the items presented twice lead to more recollection than those presented only once. Finally, these results also suggest that in the older group of participants, only for the items presented twice, intentional encoding instructions lead to more recollection and less familiarity. This finding is consistent with previous work showing that the elderly do not easily use elaborate encoding strategies, and that they need more support (here, a second exposition to the material) in order to perform a deep encoding when they are encouraged to do so with intentional learning instructions (b). (a) Bugaiska, A., Clarys, D., Jarry, C., Taconnat, L., Tapia, G., Vanneste, S., & Isingrini, M. (2007). The effect of aging in recollective experience: the processing speed and executive functioning hypothesis. Consciousness and Cognition, 16(4), 797-808. doi: 10.1016/j.concog.2006.11.007 (b) Froger, C., Bouazzaoui, B., Isingrini, M., & Taconnat, L. (2012). Study time allocation deficit of older adults: the role of environmental support at encoding? Psychology and Aging, 27(3), 577-588. doi:10.1037/a0026358 [less ▲]

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See detailThe impact of ageing on episodic memory encoding: an fMRI study
François, Sarah ULg; Angel, Lucie; Salmon, Eric ULg et al

Poster (2015, May 28)

It is now commonly accepted that a decline in episodic memory is observed with ageing: while recollection processes are impaired, familiarity seems to be relatively preserved (a). Older individuals appear ... [more ▼]

It is now commonly accepted that a decline in episodic memory is observed with ageing: while recollection processes are impaired, familiarity seems to be relatively preserved (a). Older individuals appear to recruit prefrontal areas bilaterally when their encoding is successful, while in young adults this activation is found to be left-lateralized (b). In this study, we were interested in the differences between younger and older participant regarding cerebral activity during encoding depending on whether the item elicited recollection or familiarity during the recognition phase. Twenty young volunteers (aged 19 to 29 years old) and 19 older volunteers (aged 60 to 78 years old) were presented visual stimuli depicting objects. During a first fMRI session, they were asked to make a size judgement about them. Then, in a second phase, the subjects were shown the items previously encountered during the encoding phase, as well as distractors. Participants' task was to determine which one were new and which one were seen earlier. For the latter, they also performed a Remember-Know judgement. Data were analysed using SPM8, with an event design comparing modifications in cerebral activity between the two subjects groups during encoding (1) for the items leading to recollection during the recognition phase compared to those leading to familiarity, and (2) for the items associated with familiarity during the recognition phase compared to those which were not recognized. Results show that older adults display a heightened activity in the right middle frontal gyrus, medial cingulate and paracingulate left gyri as well as in the precuneus, bilaterally when they engage recollection processes. Given that activations in these areas did not correlate with performance, they could be interepreted either as dedifferentiation or as an attempt of the ageing brain to compensate for a less elaborate encoding. However, no increase of activity was associated with familiarity processes in older adults, possibly because they are less demanding regarding attentional resources. (a) Bugaiska, A., Clarys, D., Jarry, C., Taconnat, L., Tapia, G., Vanneste, S., & Isingrini, M. (2007). The effect of aging in recollective experience: the processing speed and executive functioning hypothesis. Consciousness and Cognition, 16(4), 797-808. doi: 10.1016/j.concog.2006.11.007 (b) Duverne, S., Motamedinia, S., & Rugg, M. D. (2009). The relationship between aging, performance, and the neural correlates of successful memory encoding. Cerebral Cortex, 19(3), 733-744. doi:10.1093/cercor/bhn122 [less ▲]

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See detailThe impact of ageing on episodic memory encoding: an fMRI study
François, Sarah ULg; Angel, Lucie; Salmon, Eric ULg et al

Poster (2015, May 21)

It is now commonly accepted that a decline in episodic memory is observed with ageing: while recollection processes are impaired, familiarity seems to be relatively preserved (a). Older individuals appear ... [more ▼]

It is now commonly accepted that a decline in episodic memory is observed with ageing: while recollection processes are impaired, familiarity seems to be relatively preserved (a). Older individuals appear to recruit prefrontal areas bilaterally when their encoding is successful, while in young adults this activation is found to be left-lateralized (b). In this study, we were interested in the differences between younger and older participant regarding cerebral activity during encoding depending on whether the item elicited recollection or familiarity during the recognition phase. Twenty young volunteers (aged 19 to 29 years old) and 19 older volunteers (aged 60 to 78 years old) were presented visual stimuli depicting objects. During a first fMRI session, they were asked to make a size judgement about them. Then, in a second phase, the subjects were shown the items previously encountered during the encoding phase, as well as distractors. Participants' task was to determine which one were new and which one were seen earlier. For the latter, they also performed a Remember-Know judgement. Data were analysed using SPM8, with an event design comparing modifications in cerebral activity between the two subjects groups during encoding (1) for the items leading to recollection during the recognition phase compared to those leading to familiarity, and (2) for the items associated with familiarity during the recognition phase compared to those which were not recognized. Results show that older adults display a heightened activity in the right middle frontal gyrus, medial cingulate and paracingulate left gyri as well as in the precuneus, bilaterally when they engage recollection processes. Amongst those regions, the precuneus seems to underlie compensatory processes, allowing the elderly to perform a richer encoding, as it was previously suggested for recollection processes during recall (c). However, no increase in activity was associated with familiarity processes in older adults, possibly because they are less demanding regarding attentional resources. (a) Bugaiska, A., Clarys, D., Jarry, C., Taconnat, L., Tapia, G., Vanneste, S., & Isingrini, M. (2007). The effect of aging in recollective experience: the processing speed and executive functioning hypothesis. Consciousness and Cognition, 16(4), 797-808. doi: 10.1016/j.concog.2006.11.007 (b) Duverne, S., Motamedinia, S., & Rugg, M. D. (2009). The relationship between aging, performance, and the neural correlates of successful memory encoding. Cerebral Cortex, 19(3), 733-744. doi:10.1093/cercor/bhn122 (c) Angel, L., Bastin, C., Genon, S., Balteau, E., Phillips, C., Luxen, A., . . . Collette, F. (2013). Differential effects of aging on the neural correlates of recollection and familiarity. Cortex, 49(6), 1585-1597. doi:10.1016/j.cortex.2012.10.002 [less ▲]

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See detail[18F]UCB-H as a new PET radiotracer for Synaptic vesicle protein 2A: A first clinical trial.
Bahri, Mohamed Ali ULg; Stifkens, M; Bastin, Christine ULg et al

in Tijdschrift voor Nucleaire Geneeskunde (2015, May 09), 37(3), 1457-1458

The synaptic vesicle protein 2A (SV2A) is widely distributed in the brain and has been demonstrated to be involved in vesicle trafficking. The critical role of SV2A in proper nervous system function is ... [more ▼]

The synaptic vesicle protein 2A (SV2A) is widely distributed in the brain and has been demonstrated to be involved in vesicle trafficking. The critical role of SV2A in proper nervous system function is shown, e.g., by the fact that it is a binding site and the primary mechanism of the antiepileptic drug levetiracetam. This drug has recently been suggested to reduce synaptic deficits in a mouse model for Alzheimer’s disease. We here aimed to investigate the cerebral distribution of [18F]UCB-H, which has a high affinity with the SV2A. Dynamic PET data of the head of 4 healthy volunteers were acquired over 100 minutes after injection of 170.4 ± 24.9 MBq of GMP produced [18F]UCB-H. The arterial input function (IF) was obtained by blood sampling but also derived from the dynamic data using the correlation coefficient method. Blood data revealed a consistent amount of [18F]UCB-H in whole blood and plasma indicating a very low degree of binding of the tracer to the red blood cells. The unchanged fraction of [18F]UCB-H in plasma showed a bi-exponential behavioral decrease with a starting fraction of 92% of the injected amount of the tracer, measured at 3 min post injection. This fraction decreased to about 50% at 10 min post injection. The image-derived arterial IFs showed to be very similar to the measured ones with a peak-ratio around 0.91 and an area-under-curve ratio about 0.98. The PET images showed a high and rapid uptake of [18F]UCB-H in the grey matter structures, matching the known ubiquitous distribution of the SV2A in the brain. The kinetics of the tracer in the brain was characterized by an initial high uptake phase followed by rapid washout. For the three standard compartmental models (1-tissue, 2-tissue, and Logan Plot), similar results were obtained with both the measured and image-derived IFs. Nevertheless the two-tissue compartment model fitted the experimental data best and provided a total distribution volume of the [18F]UCB-H in the brain greater than 7 mL/cm3 and a specific distribution volume around 3 mL/cm3. Our results suggest that [18F]UCB-H is a good candidate as radiotracer for brain SV2A proteins and could be used for human studies (dosimetry has already been reported elsewhere). Image-derived IF showed to be useful for quantitative studies without the need to the arterial blood sampling. This new tracer could help to assess SV2A modifications in neurological pathologies such as Alzheimer’s disease. [less ▲]

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See detailEpisodic memory in Alzheimer’s disease: Investigation of recollection and familiarity processes
Bastin, Christine ULg

Scientific conference (2015, March 12)

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