References of "SALMON, Eric"
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See detailMétamémoire pour des informations épisodiques et sémantiques dans la maladie d’Alzheimer.
Simon, Jessica ULg; Bastin, Christine ULg; Collette, Fabienne ULg et al

in Proceedings of the "XIIème Colloque International sur le Vieillissement Cognitif" (2012, June 25)

Quelques études ont examiné la précision du jugement concernant leur propre mémoire chez des patients présentant une maladie d’Alzheimer (MA) à l’aide de la procédure « Feeling-of-Knowing » (FOK). Dans ... [more ▼]

Quelques études ont examiné la précision du jugement concernant leur propre mémoire chez des patients présentant une maladie d’Alzheimer (MA) à l’aide de la procédure « Feeling-of-Knowing » (FOK). Dans cette procédure, le participant est invité à prédire sa capacité à reconnaître parmi des distracteurs l’item qu’il n’est pas parvenu à rappeler avant de passer à la phase de reconnaissance. Chez les patients en début de MA, la précision du jugement semble préservée lorsque la tâche implique la mémoire sémantique mais apparaît altérée lorsque la tâche implique la mémoire épisodique (Perrotin & Insingrini, 2010). Il existerait donc une dissociation dans la précision du jugement métacognitif chez les patients avec MA débutante entre les domaines épisodique et sémantique. Cependant, cette hypothèse n’a jamais été examinée au sein d’une même tâche. Dans cette étude, nous avons administré une version adaptée du FOK à 23 patients avec MA débutante et 17 sujets de contrôle. Les participants voyaient des visages de personnes dont ils avaient dû étudier le nom auparavant (items épisodiques) et des visages de personnes célèbres (items sémantiques). Pour chaque visage, les participants devaient indiquer la probabilité qu’ils reconnaissent le nom de la personne sur une échelle qualitative à 4 points (« Aucune chance », « Faible chance », « Forte chance », « Je le connais (rappel) ») puis reconnaître le nom parmi 3 distracteurs. La précision des jugements a été évaluée à l’aide du score de Hamann. Une ANOVA a révélé un effet significatif d’interaction entre le groupe et le domaine mnésique (P = .05), la moindre précision du jugement en mémoire épisodique étant exacerbée chez les patients avec MA. Cette étude renforce donc l’hypothèse selon laquelle il existe une dissociation entre les domaines épisodique et sémantique dans la capacité métacognitive des patients avec MA débutante. Perrotin, A. & Insingrini, M. (2010). La métamémoire et sa fonction de monitoring dans le vieillissement normal et dans la maladie d’Alzheimer. Revue de Neurospsychologie Neurosciences cognitives et cliniques, 2(4), 299-309. [less ▲]

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See detailSelf-appraisal and medial prefrontal activation in early stage Alzheimer’s disease
Genon, Sarah ULg; Collette, Fabienne ULg; Angel, Lucie et al

Poster (2012, June 12)

Introduction Self-referential processing in healthy subjects is related to activation within cortical midline structures, such as the medial prefrontal cortex (MPFC) and the posterior cingulate cortex ... [more ▼]

Introduction Self-referential processing in healthy subjects is related to activation within cortical midline structures, such as the medial prefrontal cortex (MPFC) and the posterior cingulate cortex (PCC; Northoff et al., 2006). Little is know about the engagement of these structures during self-referential processing at different stages of Alzheimer’s disease (AD). The PCC and the MPFC have been found to be activated during a self-appraisal task of adjectives in patients at very early stage of the disease (patients with Mild Cognitive Impairment, MCI; Ries et al., 2006). In contrast, in a similar task, Ruby et al. (2009) have found that mild demented patients activated the dorsal part of the MPFC (DMPFC) to a lesser extent than healthy controls (HC). Ruby et al. did not assess depression symptoms in their patients. Yet, MPFC activations have been found to be modified during self-referential processing in depressed participants (Lemogne et al., 2012). Therefore, in this study, we examined brain correlates of self-appraisal processing in AD patients when controlling for depressive symptoms. Methods Twenty-two mild AD patients and 22 HC matched on age, level of education and gender (respectively: 76±5y; 11±3y; 12M10F) to the AD patients (respectively: 76±7y; 11±3y; 11M11F) were recruited. To control for dementia severity and depression, the participants were administrated the Mattis Dementia Rating (MDR) and the Geriatric Depression Scale (GDS). A self-appraisal task intermixed with a recognition task was administered in an fMRI experimentation. In the self-appraisal task, the participants saw adjectives and had to indicate if the trait describes them (Self-condition; SC) or the King Albert II (for men)/the Queen Fabiola (for women; Other-condition; OC). The adjectives were presented in blocks of 6 items. Participants performed 9 runs consisting in one block of SC and one block of OC followed by a recognition phase where participants were presented with the 12 adjectives that they had just previously seen randomly mixed with 12 new adjectives. They were asked to indicate for each adjective whether they had seen it in the previous task. Statistical analyses focused on the self-appraisal task. Brain activations related to the self appraisal process were isolated in each participant by subtracting brain activation related to OC items from brain activation related to SC items. Then at the group level, we examined differences between groups (HC>AD and AD>HC) and a conjunction analysis examined brain activations that were common to both groups. Preprocessing and statistical analyses were performed with SPM8 (p<.001 uncorrected with a-priori hypotheses). Results GDS scores were similar in AD (3±3) and HC (3±3; T(42) = .1; P=.9) groups. No region was found to be significantly more activated during self-appraisal process in HC than in AD and vice versa when performing direct statistical comparison. Moreover, a conjunction analysis revealed that the VMPFC was the only region commonly activated in AD and HC during self-appraisal process (Punc<.001). Conclusions Our results revealed that AD patients engaged the ventral part of the MPFC to a similar extent than HC during self-appraisal judgements. These results and the results found in patients with MCI by Ries et al. (2006) suggest that at initial stages of AD, patients engaged self-related regions when they performed judgements about themselves as HC do. The divergence with the findings by Ruby et al. (2009) may be related either to the fact that they did not controlled for depressive symptoms or to the fact that their patients showed on average lower scores at the MDR (124) than our patients (127). One can assume that engagement of the self-related regions during self-appraisal judgements in the AD patients depends on the severity of the dementia and/or depressive symptoms. In conclusion, MPFC may be engaged during self-referential processing in very mild AD patients without depressive symptoms. References: Lemogne, C., Delaveau, P., Freton, M., Guionnet, S. & Fossati, P. (2012). Medial prefrontal cortex and the self in major depression. Journal of Affective Disorders, 136, 1-11. Ries, M. L., Schmitz, T.W., Kawahara, T.N., Torgerson, B.M., Trivedi, M.A. & Johnson, S.C. (2006). Task-dependent posterior cingulated activation in mild cognitive impairment. NeuroImage, 29, 485-492. Ruby, P., Collette, F., D’Argembeau, A., Péters, F., Degueldre, C., Balteau, E., Luxen, A., Maquet, P. & Salmon, E. (2009). Perspective taking to assess self-personality: What’s modified in Alzheimer’s disease ? Neurobiology of Aging, 30(10), 1637-1651. [less ▲]

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See detailAutomatic multiclass classification of 18FDG-PET scans for the distinction between Parkinson’s disease and atypical parkinsonian syndromes
Phillips, Christophe ULg; Schrouff, Jessica ULg; Luxen, André ULg et al

Poster (2012, June 10)

Part of the difficulty in the early diagnosis of Parkinson’s disease (PD) is in differentiating it from atypical parkinsonian disorders (APS) that have a poorer prognosis such as multiple system atrophy ... [more ▼]

Part of the difficulty in the early diagnosis of Parkinson’s disease (PD) is in differentiating it from atypical parkinsonian disorders (APS) that have a poorer prognosis such as multiple system atrophy (MSA), progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS). 18flurodeoxyglucose (FDG) positron emission tomography (PET) has been recommended for the early differentiation between PD and APS [1]. Here, 120 FDG PET scans (42, 31, 26 and 21 for the PD, MSA, PSP and CBS resp.) were acquired on average 3.5 years after symptoms onset (because the initial clinical features were outside the prevailing perception for PD) to look, without any a priori assumption, for cerebral FDG uptake patterns that discriminate either between the PD and APS classes, or between the four PD, MSA, PSP and CBS classes. The diagnostic used to label the scans was defined by clinical criteria on average 4.5 years after PET assessment. [less ▲]

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See detailThe neural correlates of recollection and familiarity during aging
Angel, Lucie; Bastin, Christine ULg; Genon, Sarah ULg et al

Poster (2012, June)

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See detailAlteration de l'interaction entre le Soi et la mémoire dans la maladie d'Alzheimer
Genon, Sarah ULg; Collette, Fabienne ULg; Salmon, Eric ULg et al

in Maladie d'Alzheimer et déclin cognitif: recherche et pratique clinique (2012, May 22)

Le Soi et la mémoire sont deux systèmes en interaction chez l’homme. Ainsi, une information qui a été traitée en référence à soi fait l’objet de meilleures performances mnésiques qu’une information qui ... [more ▼]

Le Soi et la mémoire sont deux systèmes en interaction chez l’homme. Ainsi, une information qui a été traitée en référence à soi fait l’objet de meilleures performances mnésiques qu’une information qui n’est pas liée au Soi. Ce phénomène cognitif bien connu est appelé « l’effet de référence à soi en mémoire » (« Self Reference Effect », SRE ; 1). En outre, le rappel d’une information qui a été reliée à soi est davantage associé à une expérience recollective (souvenir du contexte d’apprentissage), phénomène appelé le « Self-reference recollection effect » (SRRE ; 2). Dans la maladie d’Alzheimer (MA), l’expérience recollective est sévèrement altérée (3). Si le SRE est principalement sous-tendu par l’expérience recollective, il devrait donc être diminué chez les patients avec MA. Dix-huit patients avec MA à un stade débutant et 21 sujets volontaires de contrôle ont réalisé une première tâche dans laquelle des adjectifs leur étaient présentés. Pour chaque adjectif, ils devaient dans un premier temps soit indiquer si le trait s’appliquait à eux-mêmes (condition soi) soit indiquer si le trait s’appliquait au Roi Albert/à la Reine Fabiola (condition autrui). Dans un second temps, les adjectifs des deux conditions (soi et autrui) étaient mélangés à de nouveaux adjectifs. Pour chaque adjectif, les participants devaient indiquer s’ils avaient vu l’adjectif dans les essais précédents ou non. Quelques jours plus tard, la même procédure était administrée aux participants avec un nouveau set d’adjectifs comparables à ceux de la première tâche, excepté que pour chaque adjectif que les participants indiquaient avoir préalablement vu, ils devaient décrire l’expérience qui avait guidé leur réponse (sentiment de familiarité, expérience recollective ou autre). Concernant la première tâche, l’analyse de la proportion d’adjectifs correctement reconnus révèle que le groupe contrôle présente un SRE alors que cet effet est absent dans le groupe avec MA. Concernant la seconde tâche, l’analyse des proportions de reconnaissances correctes basées (1) sur une expérience recollective et (2) sur un sentiment de familiarité révèle (1) que le groupe contrôle présente un SRRE alors que cet effet est absent dans le groupe MA, (2) que la proportion de réponses correctes basées sur un sentiment de familiarité est similaire entre les deux types d’adjectifs (soi et autrui) et ce dans les deux groupes. Chez les personnes âgées normales, l’information associée au Soi en mémoire est davantage récupérée sur base d’une expérience recollective, menant à de meilleures performances pour ce type d’information que pour une information non reliée au Soi. En revanche, chez les patients avec MA, l’interaction entre le Soi et la mémoire est altérée en ce sens que l’information relative à soi ne bénéficie pas d’une meilleure récupération en raison de la pauvre qualité du processus recollectif. Ces données suggèrent donc que chez les patients avec MA, même à un stade débutant de la maladie, la récupération en mémoire d’information relative à soi est quantitativement et qualitativement altérée. 1) T. Rogers, N. Kuiper, W. Kirker. Journal of Personality and Social Psychology 37, 677 (1977). 2) M. Conway, S. Dewhurst. Applied Cognitive Psychology 9, 1 (1995). 3) G. Della Barba. Memory 5, 657 (1997). [less ▲]

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See detailMemory testing for the early diagnosis of Alzheimer’s disease: Comparative study
Grotz, Catherine ULg; Adam, Stéphane ULg; Teunisse, Jan-Pieter et al

Poster (2012, May 11)

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See detailMemory testing for the early diagnosis of Alzheimer’s disease: Comparative study
Grotz, Catherine; Adam, Stéphane ULg; Teunisse, J-P. et al

Poster (2012, May 10)

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See detailSelf-appraisal and medial prefrontal activation in early stage Alzheimer’s disease
Genon, Sarah ULg; Collette, Fabienne ULg; Angel, Lucie et al

in Proceedings of the 1st Joint Meeting of the Belgian Association for Psychological Sciences (BAPS, Belgium) and Sociedad Espanola de Psicologia Experimental (SEPEX, Spain) (2012, May 10)

Introduction Self-referential processing in healthy subjects is related to activation within cortical midline structures, such as the medial prefrontal cortex (MPFC) and the posterior cingulate cortex ... [more ▼]

Introduction Self-referential processing in healthy subjects is related to activation within cortical midline structures, such as the medial prefrontal cortex (MPFC) and the posterior cingulate cortex (Northoff et al., 2006). The structures are known to be altered in Alzheimer’s disease (AD; Buckner et al., 2008). However, little is known about their engagement during self-referential processing in AD patients. Methods Twenty-two mild AD patients and 22 healthy controls (HC) were administered a self-appraisal task in an fMRI experimentation. The participants saw adjectives and had to indicate if the trait describes them (Self-condition; SC) or the King Albert II/the Queen Fabiola (Other-condition; OC). We examined differences between groups (HC>AD and AD>HC) and a conjunction analysis examined brain activations that were common to both groups during the self-appraisal process (p<.001 uncorrected with a-priori hypotheses). Results No region was found to be significantly more activated during self-appraisal in HC than in AD and vice versa. The VMPFC was the only region commonly activated in AD and HC during self-appraisal process (Punc<.001). Conclusions The study demonstrates that AD patients at early stages of the disease may still engage the MPFC during self-referential processing (compared to a well-known but not close “other”) as HC do. References: Northoff, G., Heinzel, A., de Greck, M., Bermpohl, F., Dobrowolny, H. & Pankseepp, J. (2006). Self-referential processing in our brain-A meta-analysis of imaging studies on the self. NeuroImage, 31, 440-457. Buckner, R.L., Andrews-Hanna, J.R., Schacter, D.L. (2008). The brain’s default network: anatomy, function and relevance to disease. Annals of the New York Academy of Sciences 1124, 1-38. [less ▲]

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See detailModulating effect of COMT genotype on the brains regions underlying inhibition
Jaspar, Mathieu ULg; Grandjean, Julien ULg; SALMON, Eric ULg et al

Conference (2012, May)

Catechol-O-methyltransferase (COMT) is an important enzyme which degrades catecholamines, such dopamine, notably in the prefrontal cortex (Männistö & Kaakkola, 1999). A large number of studies reported an ... [more ▼]

Catechol-O-methyltransferase (COMT) is an important enzyme which degrades catecholamines, such dopamine, notably in the prefrontal cortex (Männistö & Kaakkola, 1999). A large number of studies reported an effect on executive functioning of COMT genotype (Barnett & al., 2007), each genotype being associated with a different COMT enzymatic activity (Weinshilboum & al., 1999). In an event-related fMRI study, a modified form of the Stroop task was administered to 45 young adults separated in three groups according to their COMT val158met genotype : 15 homozygous val/val (VV), 15 homozygous met/met (MM) and 15 heterozygotes val/met (VM). Both behavioral and fMRI results indicated the presence of a general interference effect consistent with prior reports (Nee & al., 2007). More interestingly, group comparisons indicate that this effect is associated, for a similar behavioral performance, with increased medial frontal and precentral gyrus activity in VV and VM groups by comparison with MM group. Conversely, no supplementary brain areas were observed for the comparison of the MM to the two other groups. These observations, paralleling with the lower COMT enzymatic activity and, thus, the higher cortical dopamine level in met/met individuals, confirms our expectation of a COMT Val158Met genotype modulation of the brain regions underlying inhibition efficiency. [less ▲]

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See detailNEMA NU4-2008 Performance Evaluation for the MicroPET FOCUS 120 and Iodine-124
Taleb, Dounia ULg; Bahri, Mohamed Ali ULg; Warnock, Geoffrey ULg et al

in IEEE proceedings of ANIMMA 2011 (2012, March 12)

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See detailConnectivity within the default mode network is related to working memory performance in young but not elderly healthy adults
Yakushev, Igor; Chételat, Gael; Fischer, Florian et al

in Alzheimer's & Dementia : The Journal of the Alzheimer's Association (2012), 8(4), 81

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See detailThe influence of cognitive reserve on inter-individual variability in resting-state cerebral metabolism in normal aging
Bastin, Christine ULg; Salmon, Eric ULg; Bahri, Mohamed Ali ULg et al

in Alzheimer's & Dementia : The Journal of the Alzheimer's Association (2012), 8(4), 80-81

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See detailMemory impairments in dementia: Which memory and how does it fail?
Salmon, Eric ULg; Collette, Fabienne ULg; Genon, Sarah ULg et al

in Frontiers in Human Neuroscience (2012)

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See detailCircadian preference modulates the neural substrate of conflict processing across the day
Schmidt, Christina ULg; Peigneux, Philippe ULg; Leclercq, Yves ULg et al

in PLoS ONE (2012), 7(1), 29658

Human morning and evening chronotypes differ in their preferred timing for sleep and wakefulness, as well as in optimal daytime periods to cope with cognitive challenges. Recent evidence suggests that ... [more ▼]

Human morning and evening chronotypes differ in their preferred timing for sleep and wakefulness, as well as in optimal daytime periods to cope with cognitive challenges. Recent evidence suggests that these preferences are not a simple by-product of socio-professional timing constraints, but can be driven by inter-individual differences in the expression of circadian and homeostatic sleep-wake promoting signals. Chronotypes thus constitute a unique tool to access the interplay between those processes under normally entrained day-night conditions, and to investigate how they impinge onto higher cognitive control processes. Using functional magnetic resonance imaging (fMRI), we assessed the influence of chronotype and time-of-day on conflict processing-related cerebral activity throughout a normal waking day. Sixteen morning and 15 evening types were recorded at two individually adapted time points (1.5 versus 10.5 hours spent awake) while performing the Stroop paradigm. Results show that interference-related hemodynamic responses are maintained or even increased in evening types from the subjective morning to the subjective evening in a set of brain areas playing a pivotal role in successful inhibitory functioning, whereas they decreased in morning types under the same conditions. Furthermore, during the evening hours, activity in a posterior hypothalamic region putatively involved in sleep-wake regulation correlated in a chronotype-specific manner with slow wave activity at the beginning of the night, an index of accumulated homeostatic sleep pressure. These results shed light into the cerebral mechanisms underlying inter-individual differences of higher-order cognitive state maintenance under normally entrained day-night conditions. [less ▲]

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See detailThe neural correlates of recollection and familiarity during aging
Angel, Lucie; Bastin, Christine ULg; Genon, Sarah ULg et al

in Proceedings of the XII Colloque International sur le Vieillissement Cognitif (2012)

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See detailEvaluation de la conscience de soi dans le vieillissement normal et pathologique
Feyers, Dorothée ULg; Bastin, Christine ULg; Jedidi, Haroun ULg et al

in Brédart, Serge; Van der Linden, Martial (Eds.) Identité et cognition. Apports de la psychologie et des neurosciences cognitives (2012)

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See detailItem familiarity and controlled associative retrieval in Alzheimer’s disease: An fMRI study.
Genon, Sarah ULg; Collette, Fabienne ULg; Feyers, Dorothée ULg et al

in Frontiers in Human Neuroscience (2012)

Alzheimer’s disease (AD) is characterised by altered recollection function, with impaired controlled retrieval of associations. In contrast, familiarity-based memory for individual items may sometimes be ... [more ▼]

Alzheimer’s disease (AD) is characterised by altered recollection function, with impaired controlled retrieval of associations. In contrast, familiarity-based memory for individual items may sometimes be preserved in the early stages of the disease. This is the first study that directly examines whole brain regional activity during one core aspect of the recollection function: associative controlled episodic retrieval (CER), contrasted to item familiarity in AD patients. Cerebral activity related to associative CER and item familiarity in AD patients and healthy controls (HC) was measured with functional magnetic resonance imaging during a word-pair recognition task to which the process dissociation procedure was applied. Some patients had null CER estimates (AD–), whereas others did show some CER abilities (AD+), although significantly less than HC. In contrast, familiarity estimates were equivalent in the three groups. In AD+, as in controls, associative CER activated the inferior precuneus/posterior cingulate cortex (PCC). However, during associative CER, functional connection between this region and the hippocampus, the inferior parietal and dorsolateral prefrontal cortex (DLPFC) was significantly higher in HC than in AD+. In all three groups, item familiarity was related to activation along the intraparietal sulcus (IPS). In conclusion, whereas the preserved automatic detection of an old item (without retrieval of accurate word association) is related to parietal activation centred on the IPS, the inferior precuneus/PCC supports associative CER ability in AD patients, as in HC. However, AD patients have deficient functional connectivity during associative CER, suggesting that the residual recollection function in these patients might be impoverished by the lack of some recollection-related aspects such as autonoetic quality, episodic details and verification. [less ▲]

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