References of "Salmon, Eric"
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See detailMetabolic cerebral correlates of conjunctive and relational memory in Alzheimer's disease
Bastin, Christine ULg; Bahri, Mohamed Ali ULg; Collette, Fabienne ULg et al

Poster (2014)

Introduction. Memory deficits are the clinical hallmark of typical Alzheimer’s disease. The precise nature of these deficits however remains to be fully characterized. In this study, we investigated ... [more ▼]

Introduction. Memory deficits are the clinical hallmark of typical Alzheimer’s disease. The precise nature of these deficits however remains to be fully characterized. In this study, we investigated binding in long-term episodic memory. Relational binding processes in memory create an associative link between independent items or between items and context into episodic memories (Cohen et al., 1999). An alternative process, conjunctive binding, allows associations to be encoded as a united representation of features into a single entity (O'Reilly and Rudy, 2001; Mayes et al., 2007). The current study (1) assessed whether Alzheimer’s disease disrupt both conjunctive and relational memory, and (2) related patients’ memory performance to cerebral metabolism. Methods. Thirty patients with mild Alzheimer’s disease and 24 healthy older adults performed a source memory task where items were associated to a background color (Diana et al., 2008, 2010). In one condition, relational binding was promoted by the instruction to associate the item with another object of the same color as the background. In the other condition, color had to be integrated as an item feature (conjunctive binding). Patients’ brain metabolic activity at rest (FDG-PET) was analysed with spatio-temporal Partial Least Squares (McIntosh et al., 1996) in order to assess the relation of behavioral performance and activity in functional cerebral networks. Results. Alzheimer’s disease patients had an impaired capacity to remember item-color associations, with deficits in both relational and conjunctive memory. However, performance in the two kinds of associative memory varied independently across patients. Partial least square analyses revealed a significant pattern of metabolic activity that correlated specifically with each condition (accounting for 76.48 % of the covariance in the data; p< .05). More specifically, poor conjunctive memory was related to hypometabolism in an anterior temporal-posterior fusiform brain network, whereas relational memory correlated with metabolism in regions of the default mode network. Conclusions. These findings support the hypothesis of distinct neural systems specialized in different types of associative memory and point to heterogeneous profiles of memory alteration in Alzheimer’s disease as a function of damage to the respective neural networks. [less ▲]

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See detailBrains creating stories of selves: the neural basis of autobiographical reasoning.
D'Argembeau, Arnaud ULg; Cassol, Helena; Phillips, Christophe ULg et al

in Social Cognitive and Affective Neuroscience (2014), 9

Personal identity critically depends on the creation of stories about the self and one's life. The present study investigates the neural substrates of autobiographical reasoning, a process central to the ... [more ▼]

Personal identity critically depends on the creation of stories about the self and one's life. The present study investigates the neural substrates of autobiographical reasoning, a process central to the construction of such narratives. During fMRI scanning, participants approached a set of personally significant memories in two different ways: on some trials, they remembered the concrete content of the events (autobiographical remembering), whereas on other trials they reflected on the broader meaning and implications of their memories (autobiographical reasoning). Relative to remembering, autobiographical reasoning recruited a left-lateralized network involved in conceptual processing (including the dorsal medial prefrontal cortex (MPFC), inferior frontal gyrus, middle temporal gyrus, and angular gyrus). The ventral MPFC-an area that may function to generate personal/affective meaning-was not consistently engaged during autobiographical reasoning across participants but, interestingly, the activity of this region was modulated by individual differences in interest and willingness to engage in self-reflection. These findings support the notion that autobiographical reasoning and the construction of personal narratives go beyond mere remembering in that they require deriving meaning and value from past experiences. [less ▲]

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See detailLes modifications du fonctionnement exécutif dans le vieillissement normal
Collette, Fabienne ULg; Salmon, Eric ULg

in Psychologie Française (2014), 59(1), 41-58

Il est maintenu bien reconnu que le vieillissement cognitif est associé à une diminution des capacités exécutives. Toutefois, si des déficits sont effectivement observés au sein des différentes fonctions ... [more ▼]

Il est maintenu bien reconnu que le vieillissement cognitif est associé à une diminution des capacités exécutives. Toutefois, si des déficits sont effectivement observés au sein des différentes fonctions, des dissociations entre performances préservées/altérées ont également été observées au sein de chacune. Dans cette revue de question, nous détaillerons les effets du vieillissement dans les fonctions de mise à jour, flexibilité, inhibition et coordination de tâches doubles, ainsi que les modifications au sein des réseaux cérébraux associés à ces processus. Nous discuterons également l'influence des capacités attentionnelles, des ressources en mémoire de travail et de certaines caractéristiques génétiques sur ces modifications. [less ▲]

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See detailA Partial Least Squares Analysis of the self reference effect in Alzheimer's disease: A reply to Irish
Genon, Sarah ULg; Bastin, Christine ULg; Angel, Lucie et al

in Cortex : A Journal Devoted to the Study of the Nervous System & Behavior (2014), 54

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See detailModulating effect of COMT genotype on the brain regions underlying proactive control process during inhibition
Jaspar, Mathieu ULg; Genon, Sarah ULg; Muto, Vincenzo ULg et al

in Cortex : A Journal Devoted to the Study of the Nervous System & Behavior (2014), 50

Introduction. Genetic variability related to the catechol-O-methyltransferase (COMT) gene (Val158Met polymorphism) has received increasing attention as a possible modulator of cognitive control functions ... [more ▼]

Introduction. Genetic variability related to the catechol-O-methyltransferase (COMT) gene (Val158Met polymorphism) has received increasing attention as a possible modulator of cognitive control functions. Methods. In an event-related fMRI study, a modified version of the Stroop task was administered to three groups of 15 young adults according to their COMT Val158Met genotype [Val/Val (VV), Val/Met (VM) and Met/Met (MM)]. Based on the theory of dual mechanisms of control (Braver, et al., 2007), the Stroop task has been built to induce proactive or reactive control processes according to the task context. Results. Behavioral results did not show any significant group differences for reaction times but Val allele carriers individuals are less accurate in the processing of incongruent items. fMRI results revealed that proactive control is specifically associated with increased activity in the anterior cingulate cortex (ACC) in carriers of the Met allele, while increased activity is observed in the middle frontal gyrus (MFG) in carriers of the Val allele. Conclusion. These observations, in keeping with a higher cortical dopamine level in MM individuals, support the hypothesis of a COMT Val158Met genotype modulation of the brain regions underlying proactive control, especially in frontal areas as suggested by Braver et al. [less ▲]

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See detailThe Benefits of Errorless Learning for Serial Reaction Time Performance in Alzheimer's Disease.
Schmitz, Xavier ULg; Bier, Nathalie; Joubert, Sven et al

in Journal of Alzheimer's Disease [=JAD] (2014), 39(2), 287-300

Identifying the conditions favoring new procedural skill learning in Alzheimer’s disease (AD) could be important for patients’ autonomy. It has been suggested that error elimination is beneficial during ... [more ▼]

Identifying the conditions favoring new procedural skill learning in Alzheimer’s disease (AD) could be important for patients’ autonomy. It has been suggested that error elimination is beneficial during skill learning, but no study has explored the advantage of this method in sequential learning situations. In this study, we examined the acquisition of a 6-element perceptual-motor sequence by AD patients and healthy older adults (control group). We compared the impact of two preliminary sequence learning conditions (Errorless vs. Errorful) on Serial Reaction Time performance at two different points in the learning process. A significant difference in reaction times for the learned sequence and a new sequence was observed in both conditions in healthy older participants; in AD patients, the difference was significant only in the errorless condition. The learning effect was greater in the errorless than the errorful condition in both groups. However, while the errorless advantage was found at two different times in the learning process in the AD group, in the control group this advantage was observed only at the halfway point. These results support the hypothesis that errorless learning allows for faster automation of a procedure than errorful learning in both AD and healthy older subjects. [less ▲]

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See detailDorsomedial prefrontal metabolism and unawareness of current characteristics of personality traits in Alzheimer’s disease
Jedidi, Haroun ULg; Feyers, Dorothée ULg; Collette, Fabienne ULg et al

in Social Cognitive and Affective Neuroscience (2014)

Anosognosia is a complex symptom corresponding to a lack of awareness of one’s current clinical status. Anosognosia for cognitive deficits has frequently been described in Alzheimer’s disease (AD), while ... [more ▼]

Anosognosia is a complex symptom corresponding to a lack of awareness of one’s current clinical status. Anosognosia for cognitive deficits has frequently been described in Alzheimer’s disease (AD), while unawareness of current characteristics of personality traits has rarely been considered. We used a well-established questionnaire-based method in a group of 37 AD patients and in healthy controls to probe self- and hetero-evaluation of patients’ personality and we calculated differential scores between each participant’s and his/her relative’s judgments. A brain-behavior correlation was performed using FDG-PET images. The behavioral data showed that AD patients presented with anosognosia for current characteristics of their personality and their anosognosia was primarily explained by impaired third perspective taking. The brain-behavior correlation analysis revealed a negative relationship between anosognosia for current characteristics of personality and dorsomedial prefrontal cortex (dMPFC) activity. Behavioral and neuroimaging data are consistent with the view that impairment of different functions subserved by the dMPFC (self-evaluation, inferences regarding complex enduring dispositions of self and others, confrontation of perspectives in interpersonal scripts) plays a role in anosognosia for current characteristics of personality in AD patients. [less ▲]

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See detailPLS analysis of fMRI data on cognitive processes
Bahri, Mohamed Ali ULg; Genon, Sarah ULg; Bastin, Christine ULg et al

Conference (2013, December 12)

Cognitive processes like memory and self-referential are known to be underlined by extended neural networks. To study these complex processes, multivariate methods appear as the methods of the first ... [more ▼]

Cognitive processes like memory and self-referential are known to be underlined by extended neural networks. To study these complex processes, multivariate methods appear as the methods of the first choice since they take into account the functional integration. Partial Least Square (PLS) was used to study neural networks related to memory and self-referential processing in Alzheimer’s disease patients (AD) and two examples were presented. In the first one, we investigated the metabolic correlates of two forms of memory (conjunctive and relational memory performances) in AD. PLS identified two different brain networks highlighting correlations of the two types of memory and the glucose metabolism. In the second example, we assessed brain regions engaged during self-referential processing of information in AD patients during a task related fMRI study. PLS identified a wide brain network showing the effect of self- vs. other-referential processing. In contrast to univariate methods, PLS showed to be suitable for the study of cognitive processes. [less ▲]

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See detailThe impact of the salience of fluency in recognition memory in Alzheimer’s disease
Simon, Jessica ULg; Bastin, Christine ULg; SALMON, Eric ULg et al

Poster (2013, December 06)

According to the dual-process models, recognition memory is supported by recollection and familiarity (Yonelinas, 2002). Familiarity is a complex function that depends on several processes. One of the ... [more ▼]

According to the dual-process models, recognition memory is supported by recollection and familiarity (Yonelinas, 2002). Familiarity is a complex function that depends on several processes. One of the most important mechanisms is the sense of familiarity driven by the fluency processing (Whittlesea, 1993). The fluency can be defined by the enhancement of processing speed and the ease of processing due to an earlier encounter with the stimulus. Our objective is to explore the effect on an increase of salience of fluency cues on the recognition memory performance of patients with Alzheimer disease (AD). Sixteen AD patients and sixteen healthy elderly controls (HC) performed two conditions of a memory task. In the study phase, 25 words were presented at a rate of one word every 1.5s. Participants were instructed to read the words aloud and to try and remember them. After a break of 5 minutes, participant performed a yes/no recognition task with 25 studied words and 25 new words. In the Non-Overlap condition, the 25 studied words were composed of a subset of letters of the alphabet and the 25 new words of the remaining letters. In the Overlap condition, the 50 words were based on the whole alphabet. The two recognition tasks were separated by a delay of 24h. The capacity to discriminate between old and new items was measured by the index d’. An ANOVA on d’ scores revealed that discrimination was poorer in the AD group than in the HC and also poorer in the Overlap condition than in the Non-Overlap condition. The current results showed that to increase salience of fluency at the level of letter by eliminating letter-overlap between old and new words increases the recognition performance to the same extent in both groups but the amplitude of AD memory deficit was not reduced (Bastin, Willems, Genon, & Salmon, 2013). [less ▲]

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See detailRetirement and the onset of Alzheimer's disease: The ICTUS study
Grotz, Catherine ULg; Letenneur, luc; Bonsang, Eric et al

Conference (2013, October 03)

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