Publications of Fabienne Collette
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See detailSleep slow waves generation and medial prefrontal microstructure in healthy older individuals
Van Egroo, Maxime ULiege; Chylinski, Daphné ULiege; Narbutas, Justinas ULiege et al

Conference (2020, September 22)

Introduction. Aging is associated with alterations in sleep-wake regulation that have been associated with changes in brain structural integrity. In particular, the ability to generate slow oscillations ... [more ▼]

Introduction. Aging is associated with alterations in sleep-wake regulation that have been associated with changes in brain structural integrity. In particular, the ability to generate slow oscillations during non-rapid eye movement (NREM) sleep decreases as early as in the 5th decade of life, predominantly over frontal regions. While previous investigations have identified macrostructural brain correlates of the age-related decrement in sleep slow waves generation, their relationships with brain tissue microstructure remain poorly understood. Methods. We recorded sleep under electroencephalography in 99 healthy older individuals (mean age = 59.6 ± 5.2 years; 66 women), and we quantified slow waves generation using the overnight cumulated power density in the delta band (0.5-4 Hz) during NREM sleep over the frontal Fz derivation. All participants also underwent 3T magnetic resonance imaging (MRI) scans to investigate tissue myelin content based on quantitative magnetization transfer (MT) saturation mapping, as well as diffusion-based metrics derived from neurite orientation dispersion and density imaging (NODDI) model. A region of interest covering bilateral medial prefrontal cortices was used to extract regional grey matter values. Results. We first observed that MT signal in the medial prefrontal cortex was positively associated with higher neurite orientation dispersion (r = .30, p = .003) and density (r = .22, p = .03), supposedly reflecting preserved microstructural integrity. Crucially, overnight NREM sleep slow waves generation was significantly related to higher prefrontal MT signal (r = .22, p = .03), but not to NODDI metrics (dispersion: r = .02, p = .85; density: r = .09, p = .36). Generalized linear mixed models adjusted for demographics and total sleep time confirmed these relationships, although as a statistical trend for MT signal (F1,93 = 3.64, p = .06). Discussion. Our findings suggest a positive association between tissue myelin content within medial prefrontal grey matter and generation of slow waves during NREM sleep in aging. Preserved prefrontal myelination may facilitate neuronal synchronization through enhanced cortico-cortical connections, resulting in higher power density in the slower frequency band. Given the existing link between sleep characteristics and age-related cognitive decline, these results may have implications for successful cognitive aging. Support: FNRS, ULiège, ARC17/21-09, FEDER, WBI, Clerdent Foundation, Leon Frédéricq Foundation [less ▲]

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See detailAlzheimer’s disease genetic risk and sleep phenotypes: association with more slow-waves and daytime sleepiness
Muto, Vincenzo ULiege; Koshmanova, Ekaterina ULiege; Ghaemmaghami Tabrizi, Pouya ULiege et al

in Sleep (2020)

Study objectives: Sleep disturbances and genetic variants have been identified as risk factors for Alzheimer's disease. Our goal was to assess whether genome-wide polygenic risk scores (PRS) for AD ... [more ▼]

Study objectives: Sleep disturbances and genetic variants have been identified as risk factors for Alzheimer's disease. Our goal was to assess whether genome-wide polygenic risk scores (PRS) for AD associate with sleep phenotypes in young adults, decades before typical AD symptom onset. Methods: We computed whole-genome Polygenic Risk Scores (PRS) for AD and extensively phenotyped sleep under different sleep conditions, including baseline sleep, recovery sleep following sleep deprivation and extended sleep opportunity, in a carefully selected homogenous sample of healthy 363 young men (22.1 y ± 2.7) devoid of sleep and cognitive disorders. Results: AD PRS was associated with more slow wave energy, i.e. the cumulated power in the 0.5-4 Hz EEG band, a marker of sleep need, during habitual sleep and following sleep loss, and potentially with large slow wave sleep rebound following sleep deprivation. Furthermore, higher AD PRS was correlated with higher habitual daytime sleepiness. Conclusions: These results imply that sleep features may be associated with AD liability in young adults, when current AD biomarkers are typically negative, and the notion that quantifying sleep alterations may be useful in assessing the risk for developing AD. [less ▲]

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See detailAssociation of Sleep-Disordered Breathing With Alzheimer Disease Biomarkers in Community-Dwelling Older Adults: A Secondary Analysis of a Randomized Clinical Trial.
André, Claire; Rehel, Stéphane; Kuhn, Elizabeth et al

in JAMA Neurology (2020), 77(6), 1-10

IMPORTANCE: Increasing evidence suggests that sleep-disordered breathing (SDB) increases the risk of developing Alzheimer clinical syndrome. However, the brain mechanisms underlying the link between SDB ... [more ▼]

IMPORTANCE: Increasing evidence suggests that sleep-disordered breathing (SDB) increases the risk of developing Alzheimer clinical syndrome. However, the brain mechanisms underlying the link between SDB and Alzheimer disease are still unclear. OBJECTIVE: To determine which brain changes are associated with the presence of SDB in older individuals who are cognitively unimpaired, including changes in amyloid deposition, gray matter volume, perfusion, and glucose metabolism. DESIGN, SETTING, AND PARTICIPANTS: This cross-sectional study was conducted using data from the Age-Well randomized clinical trial of the Medit-Ageing European project, acquired between 2016 and 2018 at Cyceron Center in Caen, France. Community-dwelling older adults were assessed for eligibility and were enrolled in the Age-Well clinical trial if they did not meet medical or cognitive exclusion criteria and were willing to participate. Participants who completed a detailed neuropsychological assessment, polysomnography, a magnetic resonance imaging, and florbetapir and fluorodeoxyglucose positron emission tomography scans were included in the analyses. MAIN OUTCOMES AND MEASURES: Based on an apnea-hypopnea index cutoff of 15 events per hour, participants were classified as having SDB or not. Voxelwise between-group comparisons were performed for each neuroimaging modality, and secondary analyses aimed at identifying which SDB parameter (sleep fragmentation, hypoxia severity, or frequency of respiratory disturbances) best explained the observed brain changes and assessing whether SDB severity and/or SDB-associated brain changes are associated with cognitive and behavioral changes. RESULTS: Of 157 participants initially assessed, 137 were enrolled in the Age-Well clinical trial, and 127 were analyzed in this study. The mean (SD) age of the 127 participants was 69.1 (3.9) years, and 80 (63.0%) were women. Participants with SDB showed greater amyloid burden (t114 = 4.51; familywise error-corrected P = .04; Cohen d, 0.83), gray matter volume (t119 = 4.12; familywise error-corrected P = .04; Cohen d, 0.75), perfusion (t116 = 4.62; familywise error-corrected P = .001; Cohen d, 0.86), and metabolism (t79 = 4.63; familywise error-corrected P = .001; Cohen d, 1.04), overlapping mainly over the posterior cingulate cortex and precuneus. No association was found with cognition, self-reported cognitive and sleep difficulties, or excessive daytime sleepiness symptoms. CONCLUSIONS AND RELEVANCE: The SDB-associated brain changes in older adults who are cognitively unimpaired include greater amyloid deposition and neuronal activity in Alzheimer disease-sensitive brain regions, notably the posterior cingulate cortex and precuneus. These results support the need to screen and treat for SDB, especially in asymptomatic older populations, to reduce Alzheimer disease risk. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02977819. [less ▲]

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See detailAlzheimer s disease genetic risk and sleep phenotypes: association with more slow-waves and daytime sleepiness
Muto, Vincenzo ULiege; Koshmanova, Ekaterina ULiege; Ghaemmaghami, Pouya  et al

E-print/Working paper (2020)

Detailed reference viewed: 60 (15 ULiège)
See detailEffort as a sensitive variable of wakefulness extension and its impact on cognitive performance
Mouraux, Charlotte; Van Egroo, Maxime ULiege; Chylinski, Daphné ULiege et al

Conference (2019, November)

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See detailHow does cognitive fatigue affect Young, Middle-aged, and Older people? A distribution analysis of Time-on-Task effect by fitting the ex-Gaussian parameters to the response time distributions.
Gilsoul, Jessica ULiege; Libertiaux, Vincent; Collette, Fabienne ULiege

Conference (2019, May 14)

Introduction. Young people experiment cognitive fatigue with Time-on-Task, evidenced by increased response time (RT). Since RT data are often positively skewed, the ex-Gaussian function (characterized by ... [more ▼]

Introduction. Young people experiment cognitive fatigue with Time-on-Task, evidenced by increased response time (RT). Since RT data are often positively skewed, the ex-Gaussian function (characterized by parameters mu, sigma, and tau) properly fits RT data. In Young people, tau (representing the extreme RT) suffers from Time-on-Task. Aim. Testing Time-on-Task in Middle-aged and Older people. Method. Twenty-one Young, 17 Middle-aged, and 17 Older performed a 160-min Stroop task comprising Facilitatory, Interfering, and Neutral items which was divided into four 40-min blocks. Ex-Gaussian parameters were fitted in each block for each item types. Measures (Facilitatory_mu, Interfering_mu, Neutral_mu, Facilitatory_tau, Interfering_tau, Neutral_tau) were analyzed with GLIMMIX repeated models. Results. All mu were smaller for Young than Middle-aged and Older. Moreover, Older had a greater I_mu in Block4 as compared to Block1 and Block2. Facilitatory_tau: Middle-aged significantly increased between Block2 and Block4. I_tau: Middle-aged significantly increased between both Block1 and Block2 with Block4. NE_tau: Young significantly increased between Block1 and both Block3 and Block4 (p<.01); Middle-aged increased between both Block1 and Block2 with Block4; Older increased between Block1 and Block4. Discussion. The three groups evidenced increases in their extreme RT (tau) with Time-on-Task. Very interestingly, Middle-aged people seemed the most cognitively fatigued by the task. [less ▲]

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See detailHow does cognitive fatigue affect Young, Middle-aged, and Older people? A distribution analysis of Time-on-Task effect by fitting the ex-Gaussian parameters to the response time distributions.
Gilsoul, Jessica ULiege; Collette, Fabienne ULiege

Poster (2019, April 26)

Introduction. Young people experiment cognitive fatigue after long-lasting tasks (Time-on-Task effect), evidenced by increased response time (RT). The ex-Gaussian function properly fits RT data. Mu ... [more ▼]

Introduction. Young people experiment cognitive fatigue after long-lasting tasks (Time-on-Task effect), evidenced by increased response time (RT). The ex-Gaussian function properly fits RT data. Mu & sigma represent the Gaussian component while tau describes the exponential component (increase in extreme RT). Mu represents motor/peripheral processes and tau decisional processes. In Young, tau suffers from Time-on-Task. Aim. To test Time-on-Task effect in Middle-aged and Older. Method. Twenty-one Young, 17 Middle-aged, and 17 Older performed a 160min Stroop task comprising facilitatory (FA), interfering (I), and neutral (NE) items. The task was divided into four 40min blocks and the ex-Gaussian parameters were fitted in each block for each item types. Six measures (FA_mu, I_mu, NE_mu, FA_tau, I_tau, NE_tau) were analyzed with GLIMMIX repeated measure (p<0.05). Results. All mu were smaller in Young than in Middle-aged and Older. Moreover, Older had a greater I_mu in Block4 as compared to Block1 and Block2. FA_tau: Middle-aged significantly increased between Block2 and Block4. I_tau: Middle-aged significantly increased between both Block1 and Block2 with Block4. NE_tau: Young significantly increased between Block1 and both Block3 and Block4 (p<.01); Middle-aged increased between both Block1 and Block2 with Block4; Older increased between Block1 and Block4. Discussion. The three groups were not impaired in their motor/peripheral processes (mu) with Time-on-task except for the Older on the Interfering items, probably due to their baseline difficulties in inhibition. However, the three groups were disabled in their decisional processes as indexed by increases in their extreme RT (tau), with Middle-aged being the most cognitively fatigued. [less ▲]

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See detailDo attentional capacities and processing speed mediate the effect of age on executive functioning?
Gilsoul, Jessica ULiege; Simon, Jessica ULiege; Hogge, Michaël et al

in Neuropsychology, Development, and Cognition. Section B, Aging, Neuropsychology and Cognition (2019), 26

The executive processes are well known to decline with age, and similar data also exists for attentional capacities and processing speed. Therefore, we investigated whether these two last nonexecutive ... [more ▼]

The executive processes are well known to decline with age, and similar data also exists for attentional capacities and processing speed. Therefore, we investigated whether these two last nonexecutive variables would mediate the effect of age on executive functions (inhibition, shifting, updating, and dual-task coordination). We administered a large battery of executive, attentional and processing speed tasks to 104 young and 71 older people, and we performed mediation analyses with variables showing a significant age effect. All executive and processing speed measures showed age-related effects while only the visual scanning task performance (selective attention) was explained by age when controlled for gender and educational level. Regarding mediation analyses, visual scanning partially mediated the age effect on updating while processing speed partially mediated the age effect on shifting, updating and dual-task coordination. In a more exploratory way, inhibition was also found to partially mediate the effect of age on the three other executive functions. Attention did not greatly influence executive functioning in aging while, in agreement with the literature, processing speed seems to be a major mediator of the age effect on these processes. Interestingly, the global pattern of results seems also to indicate an influence of inhibition but further studies are needed to confirm the role of that variable as a mediator and its relative importance by comparison with processing speed. [less ▲]

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See detailLes modifications cognitives associées au vieillissement normal : d’une conception déficitaire à une vision de compensation
Collette, Fabienne ULiege

in Revue de Neuropsychologie, Neurosciences Cognitives et Cliniques (2019), 11(1), 23-25

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See detailAnosognosia and default mode subnetwork dysfunction in Alzheimer's disease
Antoine, Nicolas ULiege; Bahri, Mohamed Ali ULiege; Bastin, Christine ULiege et al

in Human Brain Mapping (2019), 40

Research on the neural correlates of anosognosia in Alzheimer's disease varied according to methods and objectives: they compared different measures, used diverse neuroimaging modalities, explored ... [more ▼]

Research on the neural correlates of anosognosia in Alzheimer's disease varied according to methods and objectives: they compared different measures, used diverse neuroimaging modalities, explored connectivity between brain networks, addressed the role of specific brain regions or tried to give support to theoretical models of unawareness. We used resting-state fMRI connectivity with two different seed regions and two measures of anosognosia in different patient samples to investigate consistent modifications of default mode subnetworks and we aligned the results with the Cognitive Awareness Model. In a first study, patients and their relatives were presented with the Memory Awareness Rating Scale. Anosognosia was measured as a patient-relative discrepancy score and connectivity was investigated with a parahippocampal seed. In a second study, anosognosia was measured in patients with brain amyloid (taken as a disease biomarker) by comparing self-reported rating with memory performance, and connectivity was examined with a hippocampal seed. In both studies, anosognosia was consistently related to disconnection within the medial temporal subsystem of the default mode network, subserving episodic memory processes. Importantly, scores were also related to disconnection between the medial temporal and both the core subsystem (participating to self-reflection) and the dorsomedial subsystem of the default mode network (the middle temporal gyrus that might subserve a personal database in the second study). We suggest that disparity in connectivity within and between subsystems of the default mode network may reflect impaired functioning of pathways in cognitive models of awareness. © 2019 The Authors. Human Brain Mapping published by Wiley Periodicals, Inc. [less ▲]

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See detailCognitive efficiency in late midlife is linked to lifestyle characteristics and allostatic load
Narbutas, Justinas ULiege; Van Egroo, Maxime ULiege; Chylinski, Daphné ULiege et al

in Aging (2019), 11

We investigated whether cognitive fitness in late midlife is associated with physiological and psychological factors linked to increased risk of age-related cognitive decline. Eighty-one healthy late ... [more ▼]

We investigated whether cognitive fitness in late midlife is associated with physiological and psychological factors linked to increased risk of age-related cognitive decline. Eighty-one healthy late middle-aged participants (mean age: 59.4 y; range: 50-69 y) were included. Cognitive fitness consisted of a composite score known to be sensitive to early subtle cognitive change. Lifestyle factors (referenced below as cognitive reserve factors; CRF) and affective state were determined through questionnaires, and sleep-wake quality was also assessed through actimetry. Allostatic load (AL) was determined through a large range of objective health measures. Generalized linear mixed models, controlling for sex and age, revealed that higher cognitive reserve and lower allostatic load are related to better cognitive efficiency. Crystallized intelligence, sympathetic nervous system functioning and lipid metabolism were the only sub-fields of CRF and AL to be significantly associated with cognition. These results show that previous lifestyle characteristics and current physiological status are simultaneously explaining variability in cognitive abilities in late midlife. Results further encourage early multimodal prevention programs acting on both of these modifiable factors to preserve cognition during the aging process. [less ▲]

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See detailAge-related decrease in cortical excitability circadian variations during sleep loss and its links with cognition
Gaggioni, Giulia ULiege; Ly, Julien; Muto, Vincenzo ULiege et al

in Neurobiology of Aging (2019), 78

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See detailPreserved wake-dependent cortical excitability dynamics predict cognitive fitness beyond age-related brain alterations.
Van Egroo, Maxime ULiege; Narbutas, Justinas ULiege; Chylinski, Daphné ULiege et al

in Communications Biology (2019), 2

Age-related cognitive decline arises from alterations in brain structure as well as in sleep-wake regulation. Here, we investigated whether preserved wake-dependent regulation of cortical function could ... [more ▼]

Age-related cognitive decline arises from alterations in brain structure as well as in sleep-wake regulation. Here, we investigated whether preserved wake-dependent regulation of cortical function could represent a positive factor for cognitive fitness in aging. We quantified cortical excitability dynamics during prolonged wakefulness as a sensitive marker of age-related alteration in sleep-wake regulation in 60 healthy older individuals (50-69 y; 42 women). Brain structural integrity was assessed with amyloid-beta- and tau-PET, and with MRI. Participants' cognition was investigated using an extensive neuropsychological task battery. We show that individuals with preserved wake-dependent cortical excitability dynamics exhibit better cognitive performance, particularly in the executive domain which is essential to successful cognitive aging. Critically, this association remained significant after accounting for brain structural integrity measures. Preserved dynamics of basic brain function during wakefulness could therefore be essential to cognitive fitness in aging, independently from age-related brain structural modifications that can ultimately lead to dementia. [less ▲]

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See detailSleep fragmentation is associated with brain tau but not amyloid-β burden in healthy older adults
Chylinski, Daphné ULiege; Rudzik, Franziska; Coppieters't Wallant, Dorothe ULiege et al

Conference (2018, November 09)

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