References of "Collette, Fabienne"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailChronic exercise differentially impacts perceptual or motor inhibition as a function of age: a cross-sectional study
Albinet, Cédric; Boucard, Geoffrey; Collette, Fabienne ULg et al

Poster (2013)

Detailed reference viewed: 20 (7 ULg)
Full Text
Peer Reviewed
See detailExploration of the mechanisms underlying the ISPC effect: Evidence from behavioral and neuroimaging data
Grandjean, Julien; D'Ostilio, Kevin ULg; Fias, Wim et al

in Neuropsychologia (2013), 51

The item-specific proportion congruent (ISPC) effect in a Stroop task – the observation of reduced interference for color words mostly presented in an incongruent color – has attracted growing interest ... [more ▼]

The item-specific proportion congruent (ISPC) effect in a Stroop task – the observation of reduced interference for color words mostly presented in an incongruent color – has attracted growing interest since the original study by Jacoby (2003). Two mechanisms have been proposed to explain the effect: associative learning of contingencies and item-specific control through word reading modulation. Both interpretations have received empirical support from behavioral data. Therefore, the aim of this study was to investigate the responsible mechanisms of the ISPC effect with the classic two-item sets design using fMRI. Results showed that the ISPC effect is associated with increased activity in the anterior cingulate (ACC), dorsolateral prefrontal (DLPFC), and inferior and superior parietal cortex. Importantly, behavioral and fMRI analyses specifically addressing the respective contribution of associative learning and item-specific control mechanisms brought support for the contingency learning account of the ISPC effect. Results are discussed in reference to task and procedure characteristics that may influence the extent to which item-specific control and/or contingency learning contribute to the ISPC effect. [less ▲]

Detailed reference viewed: 28 (6 ULg)
Full Text
Peer Reviewed
See detailAssociative memory in aging: The effect of unitization on source memory
Bastin, Christine ULg; Diana, Rachel A.; Simon, Jessica ULg et al

in Psychology & Aging (2013), 28(1), 275-283

In normal aging, memory for associations declines more than memory for individual items. Unitization is an encoding process defined by creation of a new single entity to represent a new arbitrary ... [more ▼]

In normal aging, memory for associations declines more than memory for individual items. Unitization is an encoding process defined by creation of a new single entity to represent a new arbitrary association. The current study tested the hypothesis that age-related differences in associative memory can be reduced following encoding instructions that promote unitization. In two experiments, groups of 20 young and 20 older participants learned new associations between a word and a background color under two conditions. In the item detail condition, they had to imagine that the item is the same color as the background; an instruction promoting unitization of the associations. In the context detail condition, that did not promote unitization, they had to imagine that the item interacted with another colored object. At test, they had to retrieve the color that was associated to each word (source memory). In both experiments, the results showed an age-related decrement in source memory performance in the context detail but not in the item detail condition. Moreover, Experiment 2 examined receiver operating characteristics in older participants and indicated that familiarity contributed more to source memory performance in the item detail than in the context detail condition. These findings suggest that unitization of new associations can overcome the associative memory deficit observed in aging, at least for item-color associations. [less ▲]

Detailed reference viewed: 72 (10 ULg)
Full Text
Peer Reviewed
See detailVerbal learning in Alzheimer’s disease and mild cognitive impairment:fine-grained acquisition and short-delay consolidation performance and neural correlates
Genon, Sarah ULg; Collette, Fabienne ULg; Moulin, Chris et al

in Neurobiology of Aging (2013), 34

The aim of this study was to examine correlations between acquisition and short-delay consolidation and brain metabolism at rest measured by fluorodeoxyglucose positron emission tomography (FDG-PET) in 44 ... [more ▼]

The aim of this study was to examine correlations between acquisition and short-delay consolidation and brain metabolism at rest measured by fluorodeoxyglucose positron emission tomography (FDG-PET) in 44 Alzheimer’s disease (AD) patients, 16 patients with mild cognitive impairment (MCI) who progressed to dementia (MCI-AD), 15 MCI patients who remained stable (MCI-S, 4–8 years of follow-up), and 20 healthy older participants. Acquisition and short-delay consolidation were calculated respectively as mean gained (MG) and lost (ML) access to items of the California Verbal Learning Task. MG performance suggests that acquisition is impaired in AD patients even at predementia stage (MCI-AD). ML performance suggests that short-delay consolidation is deficient only in confirmed AD patients. Variations in acquisition performance in control participants are related to metabolic activity in the anterior parietal cortex, an area supporting task-positive attentional processes. In contrast, the acquisition deficit is related to decreased activity in the lateral temporal cortex, an area supporting semantic processes, in patients at an early stage of AD and is related to metabolic activity in the hippocampus, an area supporting associative processes, in confirmed AD patients. [less ▲]

Detailed reference viewed: 67 (15 ULg)
Peer Reviewed
See detailSelf et mémoire dans la maladie d'Alzheimer
Collette, Fabienne ULg

Conference (2012, November 20)

Detailed reference viewed: 29 (9 ULg)
Peer Reviewed
See detailDoes processing speed protect from age-related decline in cognitive control ?
Manard, Marine ULg; Carabin, Delphine; Collette, Fabienne ULg

Poster (2012, October 27)

Age-related difficulties have been reported on proactive control whereas reactive control seems to remain intact (Braver, Gray, & Burgess, 2007; Braver, 2012). This study investigated the potential ... [more ▼]

Age-related difficulties have been reported on proactive control whereas reactive control seems to remain intact (Braver, Gray, & Burgess, 2007; Braver, 2012). This study investigated the potential influence of speed of processing abilities on the age-related decline in proactive control. We used a working memory recognition paradigm involving proactive or reactive cognitive control by manipulating the interference level across items. 80 young adults (18-29 years old) and 80 healthy older adults (60-89 years old) were included. The main results revealed significant effects of age on sensitivity to interference. As expected, reactive control performance remained intact with aging (similar interference effect in the two groups). In contrast, we observed a larger interference effect in the proactive condition in aging. Finally, when the groups are matched according to their processing speed (assessed by the Code task of the WAIS III, with both younger and older adults having a score comprised between 60 and 93), the effect of age on sensitivity to interference disappeared. In other words, when younger and older adults had similar speed of processing abilities, no age-related proactive control decline was observed. In conclusion, beyond the fact that this study confirms the selective age-related decline in proactive control, it also indicates that speed of processing, a measure considered as reflecting the integrity of cognitive functioning during aging (Salthouse, 1996), influences the efficiency of proactive control in that population. [less ▲]

Detailed reference viewed: 15 (1 ULg)
Full Text
Peer Reviewed
See detailDoes processing speed protect from age-related decline in cognitive control?
Manard, Marine ULg; Carabin, Delphine; Collette, Fabienne ULg

in Frontiers in Human Neuroscience (2012, October 27)

Age-related difficulties have been reported on proactive control whereas reactive control seems to remain intact (Braver, Gray, & Burgess, 2007; Braver, 2012). This study investigated the potential ... [more ▼]

Age-related difficulties have been reported on proactive control whereas reactive control seems to remain intact (Braver, Gray, & Burgess, 2007; Braver, 2012). This study investigated the potential influence of speed of processing abilities on the age-related decline in proactive control. We used a working memory recognition paradigm involving proactive or reactive cognitive control by manipulating the interference level across items. 80 young adults (18-29 years old) and 80 healthy older adults (60-89 years old) were included. The main results revealed significant effects of age on sensitivity to interference. As expected, reactive control performance remained intact with aging (similar interference effect in the two groups). In contrast, we observed a larger interference effect in the proactive condition in aging. Finally, when the groups are matched according to their processing speed (assessed by the Code task of the WAIS III, with both younger and older adults having a score comprised between 60 and 93), the effect of age on sensitivity to interference disappeared. In other words, when younger and older adults had similar speed of processing abilities, no age-related proactive control decline was observed. In conclusion, beyond the fact that this study confirms the selective age-related decline in proactive control, it also indicates that speed of processing, a measure considered as reflecting the integrity of cognitive functioning during aging (Salthouse, 1996), influences the efficiency of proactive control in that population. [less ▲]

Detailed reference viewed: 49 (16 ULg)
Full Text
Peer Reviewed
See detailEvidence for a role of a cortico-subcortical network for automatic and unconscious motor inhibition of manual responses
D'Ostilio, Kevin ULg; Collette, Fabienne ULg; Phillips, Christophe ULg et al

in PLoS ONE (2012)

It is now clear that non-consciously perceived stimuli can bias our decisions. Although previous researches highlighted the importance of automatic and unconscious processes involved in voluntary action ... [more ▼]

It is now clear that non-consciously perceived stimuli can bias our decisions. Although previous researches highlighted the importance of automatic and unconscious processes involved in voluntary action, the neural correlates of such processes remain unclear. Basal ganglia dysfunctions have long been associated with impairment in automatic motor control. In addition, a key role of the medial frontal cortex has been suggested by administrating a subliminal masked prime task to a patient with a small lesion restricted to the supplementary motor area (SMA). In this task, invisible masked arrows stimuli were followed by visible arrow targets for a left or right hand response at different interstimuli intervals (ISI), producing a traditional facilitation effect for compatible trials at short ISI and a reversal inhibitory effect at longer ISI. Here, by using fast event-related fMRI and a weighted parametric analysis, we showed BOLD related activity changes in a cortico-subcortical network, especially in the SMA and the striatum, directly linked to the individual behavioral pattern. This new imaging result corroborates previous works on subliminal priming using lesional approaches. This finding implies that one of the roles of these regions was to suppress a partially activated movement below the threshold of awareness. [less ▲]

Detailed reference viewed: 33 (8 ULg)
Peer Reviewed
See detailDifference in neural correlates of discrimination during sleep deprivation in PER3 homozygous
Shaffii-Le Bourdiec, Anahita; Muto, Vincenzo ULg; Jaspar, Mathieu ULg et al

Poster (2012, September 07)

Detailed reference viewed: 31 (8 ULg)
See detailInfluence of sleep homeostasis and circadian rhythm on executive discriminative ability during a constant routine
Jaspar, Mathieu ULg; Meyer, Christelle ULg; Muto, Vincenzo ULg et al

Poster (2012, September)

Introduction & Objectives The human brain upholds cognitive performance throughout a waking day due to putative circadian (C) arousal signal (1) which counteracts the increase in homeostatic (H) sleep ... [more ▼]

Introduction & Objectives The human brain upholds cognitive performance throughout a waking day due to putative circadian (C) arousal signal (1) which counteracts the increase in homeostatic (H) sleep pressure associated to the deterioration in brain efficiency. When wakefulness is extended into the circadian night, maintenance of cognitive performance is jeopardized (Fig.1). Some individuals are very vulnerable to the negative effects of sleep loss and circadian misalignment, whereas others are resilient (3). These individuals differences can be readily explained within the conceptual framework of the circadian and homeostatic regulation of performance (4,5) but also by individual genetic differences and notably the PERIOD3 gene polymorphism (6). In this experiment, we investigated the consequences of sleep deprivation on cognitive performance during a working memory task (3-back). Following the signal detection theory, the ability to discriminate target from non-target stimuli is estimated by d prime (d') and criterion (cr). Here we assessed whether d' and cr were modulated by the raising sleep need and the oscillatory circadian signal. We also tested whether the individual vulnerability to sleep loss predicted by the PERIOD3 gene polymorphism influences this cognitive modulation, which is also driven by the sleep/wake regulation. Materials and Methods Population: Thirty-five right-handed healthy young volunteers aged from 19 to 26 (17 females) were recruited on the basis of their PER3 polymorphism. From a sample of about 400 screened volunteers, twelve 5/5 and twenty-three 4/4 homozygotes (matched for age, gender, chronotype, IQ, and level of education at the group level) participated in this study. Study protocol: Participants wore actigraphs for three weeks before the laboratory study. The first two weeks allowed us to determine their habitual sleep/wake schedule. During the third one, a strict sleep schedule adjusted on two possible timetables (00:00-08:00 or 01:00-09:00) was imposed in order to stagger fMRI sessions. Compliance to this schedule was again checked by wrist actigraphy and sleep diaries. The laboratory study began in the evening of day 1 and ran over 5 nights (Fig. 2). During the first 2 nights (habituation and baseline), the volunteers slept according to habitual sleep/wake schedule. Participants remained awake from the morning of day 3 for 42 hours. During this period, they remained in a semi-recumbent position, under dim light conditions (5 lux, eye level), with no information on clock time, in a constant routine protocol (CR). Saliva samples was hourly collected for melatonin analysis. Every 2 hours, volunteers received calibrated isocaloric snacks, behavioral data were collected and waking EEG recorded. During CR, behavioral measures were used to assess subjective (Karolinska Sleepiness Scale, KSS) and objective alertness (psychomotor vigilance task [PVT]). Executive functioning efficiency was assessed using the 3-back (Fig. 3) and SART tasks. During fMRI, participants performed alternating blocks of 0- and 3-back task. D’ and cr (Fig. 4) were analyzed with mixed-model analysis of variance (PROC Mixed), with main factors “session” and “genotype” (PER3 4/4 & PER3 5/5). All p-values derived from r-ANOVAs were based on Huynh-Feldt's (H-F) corrected degrees of freedom (p<0.05). Exploratory analysis assessed theoretical coefficients for the homeostatic sleep pressure (derived from a quasi-linear function) and the circadian oscillation (as a 24-hour period sine wave) were utilized in a multiple regression model to predict d’ and cr performance during the CR. Before these analyses, d’ and cr have been normalized using a z-score transformation. Results. Analyses on d’ 1. MIXED MODEL : Significant effect of sessions (F(12,385) = 17.16, p < 0.0001), but no group effect (F(1,133) = 0.00, p = 0.99) or interaction (F(12,385) = 1.51, p = 0.11). 2. REGRESSION: Significant regression (R² = 0.24, F(2,440) = 69.94, p <0.0001). The two predictors are significant (homeostat: p < 0.0001 ; circadian: p < 0.0001). Analyses on cr 1. MIXED MODEL : Significant effect of sessions (F(12,385) = 4.12, p < 0.0001), but no group effect (F(1,133) = 0.00, p = 0.99) or interaction (F(12,385) = 0.75, p = 0.71). 2. REGRESSION: Significant regression (R² = 0.04, F(2,440) = 9.35 , p = 0.0001). Only one predictor was significant (homeostat: p < 0.0001 ; circadian: p = 0.96). Conclusion These preliminary results show that both sleep homeostatic pressure and circadian factors influence executive discriminative ability during sleep loss, as assessed by signal detection theory (d’). Decision criterion (cr) appears modulated only by homeostatic sleep pressure. The difference between these two parameters could be explained by the theoretical modeling of the circadian oscillation and future analyses will incorporate individual experimentally-derived homeostatic and circadian parameters. Neither discrimination ability (d’) or criterion (cr) seem sensitive measures of individual cognitive vulnerability to sleep loss predicted by PER3 polymorphism. REFERENCES (1) Aston-Jones. Sleep Med. 2005, 6(Suppl 1), S3-7. (2) Dijk & Archer. Sleep Med. Rev. 2010, 14, 151-160.(3) Van Dongen & al. Sleep. 2004, 27, 423-433. (4) Mongrain & al. J. Sleep Res. 2006, 15, 162-166. (5) Van Dongen et al. Sleep. 2007, 30, 1129-1143. (6) Groeger & al. Sleep. 2008, 31, 1159-1167. (7) Vandewalle & al. J. Neuro. 2009, 29, 7948-7956. ACKNOWLEDGEMENTS & SPONSORS Cyclotron Research Centre (CRC) ; Belgian National Funds of Scientific Research (FNRS) ; Actions de Recherches Concertées (ARC, ULg) – Fondation Médicale Reine Elisabeth (FMRE) ; Walloon Excellence in Lifesciences and Biotechnology (WELBIO) ; Wellcome Trust ; Biotechnology and Biological Sciences Research Council (BBSRC) [less ▲]

Detailed reference viewed: 116 (28 ULg)
See detailInfluence of sleep homeostasis and circadian rhythm on waking EEG oscillations during a constant routine
Muto, Vincenzo ULg; Meyer, Christelle ULg; Jaspar, Mathieu ULg et al

Poster (2012, September)

Introduction & Objectives Human sleep and wake EEG oscillations are modulated by complex non-additive interaction between homeostatic and circadian processes. Quantitative analysis of EEG data, during ... [more ▼]

Introduction & Objectives Human sleep and wake EEG oscillations are modulated by complex non-additive interaction between homeostatic and circadian processes. Quantitative analysis of EEG data, during extended wakefulness, indicate that its frequency-specificity is influenced by both factors, such that low-frequencies (<8Hz) increase with time spent awake (1), thus more homeostatically-driven, while alpha activity undergoes a clear circadian modulation (2). Interindividual differences in sleep-wake regulation in young volunteers are associated with the variable-number tandem-repeat (VNTR) polymorphism in the coding region of the circadian clock gene PERIOD3 (PER3). Individuals homozygous for the longer allele of PER3 (PER35/5) were reported to generate more slow wave activity during NREM sleep and theta activity during wakefulness, relative to individuals with the shorter allele (PER34/4). However, the phase and amplitude of circadian markers do not differ between these genotypes (3). Here we tested the hypothesis if fluctuations in the dynamics of waking EEG frequency-specificity are modulated by a polymorphism in the clock gene PER3, under 42h of sustained wakefulness. Materials and Methods Population. A total of 400 young men and women were recruited, from whom DNA samples and questionnaire data were collected. On the basis of their PER3 polymorphism, 35 healthy young volunteers (age: 19-26 y; 17 females) were recruited, out of which twelve were PER35/5 and twenty-three PER34/4 homozygotes, and matched by age, gender, level of education, chronotype and IQ at the group level. Study protocol. The laboratory part of this study began in the evening of day 1 until day 5 (Fig. 1). During the first 2 nights (habituation and baseline), volunteers followed one out of two possible sleep-wake schedules (00:00-08:00 or 01:00-09:00). Thereafter, participants underwent approximately 42 hours of sustained wakefulness under constant routine (CR) conditions (semi-recumbent position, dim light <5 lux, no time-of-day information), and a subsequent recovery sleep episode. EEG recordings. Continuous EEG measurements with 9 EEG channels (F3, Fz, F4, C3, Cz, C4, Pz, O1, O2) were performed throughout the CR. Waking EEG was recorded every 2-h, during a modified version of the Karolinska Drowsiness Test (KDT) (4). Data presented here pertain to the last 60-sec of KDT, during which subjects were instructed to relax, to fixate a dot displayed on a screen ca. 75cm and to try to suppress blinks. After re-referencing to mean mastoids, recordings were scored using Rechtschaffen criteria. The 1-min EEGs during the KDT were manually and visually scored for artifacts (eye blinks, body movements, and slow eye movements) offline by 2 independent observers. The absolute EEG power density was then calculated for artifact-free 2-s epochs in the frequency range of 0.5 to 20 Hz , overlapping by 1 second using the pwelch function in MATLAB (7.5.0). For data reduction, power density of artifact-free 2-s epochs was averaged over 20-s epochs. Statistics. Waking EEG delta (0.75-4.5Hz), theta (4.75-7.75Hz) and alpha (8-12.0Hz) power density computed on Central derivation (Cz) were analyzed with a mixed-model analysis of variance (PROC Mixed), with main factors “elapsed time awake” and “genotype” (PER34/4 and PER35/5), and the interaction of these two factors. All p-values derived from r-ANOVAs were based on Huynh-Feldt's (H-F) corrected degrees of freedom (p<0.05). Multiple comparisons were performed using Tukey-Kramer test. Theoretical coefficients for the homeostatic sleep pressure (derived from a quasi-linear function) and the circadian oscillation (24-hour period sine wave) were used in a multiple regression model to predict delta, theta and alpha activity during the CR. Prior to multiple regression analysis, data were normalized according to PROC Transreg, in order to derive the best normalization method for linear and non-linear datasets. Results. Delta activity Analysis of delta activity yielded a significant main effect of “elapsed time awake” (F=5.31; p < 0.0001), albeit no significant effects for “genotype” (F=0.01; p = 0.94) nor for the interaction of these factors (F=0.85; p = 0.65). The multiple regression model revealed a significant regression (R² = 0.0433 Adj. R² = 0.0404; F = 15.24; p <0.0001), for the homeostat (p < 0.0001 ) and circadian (p = 0.0006) coefficients. Theta activity Analysis of theta activity yielded a significant main effect of “elapsed time awake” (F= 12.2; p < 0.0001), although no significant effects for “genotype” (F= 0.1; p = 0.70) nor for the interaction of these factors (F= 0.67; p = 0.86). The multiple regression model revealed a significant regression (R²= 0.072 Adj. R² =0.069; F= 26.36; p <0.0001), for the homeostat (p < 0.0001 ) and circadian (p < 0.0001 ) coefficients. Alpha activity Analysis of alpha activity yielded a significant main effect of “elapsed time awake”(F=3.43; p < 0.0001), although no significant effects for “genotype” (F = 0.01; p = 0.92) nor for the interaction of these factors (F= 1.23; p = 0.22). The multiple regression model revealed a significant regression (R²=0.052; Adj. R²=0.05; F =18.63; p <0.0001), for the homeostat (p = 0.0012) and for the circadian (p < 0.0001) coefficients. Conclusion Our results indicate that fluctuations in the dynamics of waking EEG activity are modulated by the circadian and homeostatic processes, although the magnitude of these differences are not underlined by a polymorphism in the clock gene PER3. REFERENCES 1. Cajochen C, Brunner DP, Kräuchi K, Graw P, Wirz-Justice A. Power density in theta/alpha frequencies of the waking EEG progressively increases during sustained wakefulness. Sleep. 1995, 10:890-894. 2. Cajochen C, Wyatt JK, Czeisler CA, Dijk DJ.Separation of circadian and wake duration-dependent modulation of EEG activation during wakefulnessNeuroscience. 2002, 114:1047-60. 3. Viola AU, Archer SN, James LM, Groeger JA, Lo JC, Skene DJ, von Schantz M, Dijk DJ PER3 polymorphism predicts sleep structure and waking performance. Curr Biol 2007,17:613–618. 4. Gillberg M, Kecklund G, Akerstedt T. Relations between performance and subjective rating of sleepiness during a night awake. Sleep 1994, 17:236-241. ACKNOWLEDGEMENTS & SPONSORS Cyclotron Research Centre (CRC) ; Belgian National Funds of Scientific Research (FNRS) ; Actions de Recherche Concertées (ARC, ULg) – Fondation Médicale Reine Elisabeth (FMRE) ; Walloon Excellence in Lifesciences and Biotechnology (WELBIO) ; Wellcome Trust ; Biotechnology and Biological Sciences Research Council (BBSRC) [less ▲]

Detailed reference viewed: 115 (16 ULg)
Peer Reviewed
See detailDoes processing speed protect from age-related decline in cognitive control?
Manard, Marine ULg; Carabin, Delphine; Collette, Fabienne ULg

Poster (2012, August 30)

Age-related difficulties have been reported on proactive control whereas reactive control seems to remain intact. This study investigated the potential influence of speed of processing abilities on the ... [more ▼]

Age-related difficulties have been reported on proactive control whereas reactive control seems to remain intact. This study investigated the potential influence of speed of processing abilities on the age-related decline in proactive control. We used a working memory recognition paradigm involving proactive or reactive cognitive control by manipulating the interference level across items. 80 young adults (18-29 years old) and 80 healthy older adults (60-89 years old) were included. Main results revealed significant effects of age on interference sensitivity. As expected, reactive control performance remained intact with aging (similar interference effect in the two groups). In contrast, we observed a larger interference effect in the proactive condition in aging. Finally, when the groups are matched according to their processing speed (assessed by the Code task of the WAIS III, with both younger and older adults having a score comprised between 60 and 93), the effect of age on sensitivity to interference disappeared. In other words, when younger and older adults had similar speed of processing abilities, no age-related proactive control decline was observed. In conclusion, beyond the fact that this study confirms the selective age-related decline in proactive control, it also indicates that speed of processing, a measure considered as reflecting the integrity of cognitive functioning during aging, influences the efficiency of proactive control in that population. [less ▲]

Detailed reference viewed: 37 (12 ULg)
Full Text
Peer Reviewed
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 Proceedings of the Amsterdam Memory Slam 2012 (2012, August 30)

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 early stages of the disease. This is the first study that directly examines whole brain regional activity engaged 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+ like 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 the dorsolateral prefrontal cortex was significantly higher in HC than in AD+. In the 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 a 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 residual recollection function in these patients might be impoverished by lack of some recollection-related aspects such as autonoetic quality, episodic details and verification. [less ▲]

Detailed reference viewed: 41 (5 ULg)
Full Text
Peer Reviewed
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 ▲]

Detailed reference viewed: 106 (23 ULg)
Peer Reviewed
See detailDoes fluid intelligence protect from age-related decline in cognitive control ?
Manard, Marine ULg; Carabin, Delphine; Collette, Fabienne ULg

Poster (2012, June 25)

Age-related difficulties have been reported on proactive control whereas reactive control seems to remain intact. This study investigated the potential influence of fluid intelligence capacity on the age ... [more ▼]

Age-related difficulties have been reported on proactive control whereas reactive control seems to remain intact. This study investigated the potential influence of fluid intelligence capacity on the age-related decline in proactive control. We used a working memory recognition paradigm involving proactive or reactive cognitive control by manipulating the interference level across items. 80 young adults (18-29 years old) and 80 healthy older adults (60-89 years old) were included. The main results revealed significant effects of age and fluid intelligence capacity on sensitivity to interference. As expected, reactive control performance remained intact with aging (similar interference effect in the two groups). In contrast, we observed a larger interference effect in the proactive condition in aging. Finally, older participants with similar level of fluid intelligence to young adults showed no proactive control age-related decrement. Beyond the fact that this study confirms the selective age-related decline in proactive control, it also indicates that the level of fluid intelligence influences the efficiency of proactive control in aging. [less ▲]

Detailed reference viewed: 49 (11 ULg)
Full Text
Peer Reviewed
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 ▲]

Detailed reference viewed: 43 (7 ULg)