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See detailPreserved automatic inhibition effect after 1 Hz repetitive transcranial magnetic stimulation over the supplementary motor area
D'Ostilio, Kevin ULg; CREMERS, Julien ULg; DELVAUX, Valérie ULg et al

Poster (2013)

Background: It is widely accepted that medial frontal regions are involved in voluntary action control. Indeed, Sumner et al. (2007) have recently suggested that one of the mechanisms through which the ... [more ▼]

Background: It is widely accepted that medial frontal regions are involved in voluntary action control. Indeed, Sumner et al. (2007) have recently suggested that one of the mechanisms through which the supplementary motor area (SMA) contributes to voluntary control is automatic and unconscious motor inhibition. In this study, they administered a visuo-motor subliminal masked prime task (Eimer & Schlaghecken, 2003) to two patients with micro-lesions of the SMA and demonstrated an absence of automatic and unconscious inhibition as evoked by masked prime stimuli. This finding has been supported by neuroimaging data (D'Ostilio et al., 2012). Here, the aim of our research was to corroborate this result by means of a “virtual lesion” approach. Methods: For this purpose, we examined the effects of 1 Hz rTMS (train of 20 min; stimulus intensity 120 % of resting motor threshold) over the SMA of ten healthy volunteers, previously localized by functional magnetic resonance imaging (fMRI), on reaction time (RT) performance in the subliminal masked prime task. The functional localizer experiment consisted of four blocks of sequential finger tapping and 15 s of rest after each block. Imaging data were analyzed with SPM 8 and then were imported into the Brainsight software version 2.1.5. With such system, we were able to navigate across the subjects’ brain. The peak voxel in the SMA for each subject (at a statistical threshold of p < 0.05 uncorrected) was used as a target point for the rTMS session. Results: The mean motor threshold was 50.9 % of maximal stimulator output (SD: ± 4.86 %). Wilcoxon tests showed a significant effect of compatibility on RTs (sham: Z = 2.7, p = 0.007; rTMS: Z = 2.8, p = 0.005) and accuracy rate (sham: Z = 2.5, p = 0.01; rTMS: Z = 2.1, p = 0.03), subjects being slower and making more errors in compatible trials (sham: 391.64 ± 52 ms, 87.3 % of accuracy; rTMS: 396.66 ± 37 ms, 86.3 % of accuracy) in comparison to incompatible trials (sham: 357.45 ± 36 ms, 92.5 % of accuracy; rTMS: 356.25 ± 28 ms, 92.7 % of accuracy), suggesting motor inhibition. However, this NCE was preserved after rTMS over the SMA (RTs: Z = 0.87, p = 0.39; accuracy rate: Z = 0.71, p = 0.47). Conclusions: We conclude that long trains of low intensity 1 Hz rTMS did not affect the modulation of RT by subliminal stimuli, suggesting that the SMA might not be mandatory for the implementation of this automatic process. The limitation of this study is relative to the neural efficacy argument because we are not sure that TMS was strong enough to disturb the redundant organizational processing in the SMA or that other regions were not able to compensate for the virtually lesioned area. [less ▲]

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See detailPreserved familiarity-based recognition memory in a case of global amnesia
Bastin, Christine ULg; Van der Linden, Martial ULg; Charnallet, Annik et al

in Journal of Cognitive Neuroscience (2002), 14(Supplemental), 32

Whether recognition memory can be preserved relative to recall in global amnesia is a matter of debate. Some studies suggest that amnesic patients with selective lesion to the hippocampal circuit show a ... [more ▼]

Whether recognition memory can be preserved relative to recall in global amnesia is a matter of debate. Some studies suggest that amnesic patients with selective lesion to the hippocampal circuit show a relatively normal recognition memory in the presence of impaired recall. However, other findings did not support this assumption. We investigated the recognition memory performance of a patient (ER) who became amnesic following a carbon monoxide poisoning. The MR scan revealed bilateral lesions to the pallidum. Based on the aetiology, a hippocampal lesion is suspected, but needs to be confirmed by a volumetric analysis. The recall and recognition performance of the patient was tested by means of the nonverbal subtests of the Doors and People Test Battery, which were matched on difficulty. On these subtests, ER’s recall performance was much more impaired than his recognition memory. ER’s recognition memory performance was further examined on a yes-no and a forced-choice recognition memory task, using faces as material. On the yes-no task, ER’s hit rate was normal, but he made a lot of false alarms compared to control subjects. By contrast, his forced-choice recognition memory was completely normal. This suggests that ER is able to use the familiarity process to make recognition decisions. Familiarity and recollection were finally investigated with a recognition task using the Process Dissociation Procedure (Jacoby, 1991). On this task, ER’s familiarity score was normal, whereas his recollection score was lower. These results support the assumption that familiarity-based recognition memory can be preserved in amnesia. [less ▲]

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See detailPreserved feedforward but impaired top-down processes in the vegetative state.
Boly, Mélanie ULg; Garrido, Marta Isabel; Gosseries, Olivia ULg et al

in Science (2011), 332(6031), 858-62

Frontoparietal cortex is involved in the explicit processing (awareness) of stimuli. Frontoparietal activation has also been found in studies of subliminal stimulus processing. We hypothesized that an ... [more ▼]

Frontoparietal cortex is involved in the explicit processing (awareness) of stimuli. Frontoparietal activation has also been found in studies of subliminal stimulus processing. We hypothesized that an impairment of top-down processes, involved in recurrent neuronal message-passing and the generation of long-latency electrophysiological responses, might provide a more reliable correlate of consciousness in severely brain-damaged patients, than frontoparietal responses. We measured effective connectivity during a mismatch negativity paradigm and found that the only significant difference between patients in a vegetative state and controls was an impairment of backward connectivity from frontal to temporal cortices. This result emphasizes the importance of top-down projections in recurrent processing that involve high-order associative cortices for conscious perception. [less ▲]

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See detailPréserver l'égalité des chances
Durand, Pascal ULg

Article for general public (1995)

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See detailPreserver le fonctionnement du cerveau...par la pratique d'une activite physique?
Garraux, Gaëtan ULg

in Revue Médicale de Liège (2008), 63(5-6), 293-8

Over the last few years, there has been an increasing interest in the relationship between brain function and physical exercise. Preliminary evidence from observational and interventional studies in ... [more ▼]

Over the last few years, there has been an increasing interest in the relationship between brain function and physical exercise. Preliminary evidence from observational and interventional studies in humans suggests a positive and robust effect of chronic aerobic exercise on several brain functions across the entire lifespan. Physical activity and exercise might also serve to reduce the risk of age-associated neurological disorders such as Alzheimer's and Parkinson's diseases. The mechanisms underlying these beneficial effects remain poorly understood. More scientific work is needed before disseminating more specific recommendations to the general population. [less ▲]

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See detailPréserver les écosystèmes forestiers naturels
Dufrêne, Marc ULg; Jacquemart, Anne-Laure

in Louvain : Revue Mensuelle de l'Université Catholique de Louvain et de l'Association des Anciens et Amis de l'UCL (2011), 188

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See detailPréserver plutôt que reconstruire
LAMBERT, France ULg

Conference (2012, January 13)

Chacun d’entre nous est familier avec la résorption typique de la crête alvéolaire après l’extraction d’une dent et particulièrement dans le secteur esthétique. Cette perte de tissus, entraîne fréquemment ... [more ▼]

Chacun d’entre nous est familier avec la résorption typique de la crête alvéolaire après l’extraction d’une dent et particulièrement dans le secteur esthétique. Cette perte de tissus, entraîne fréquemment la nécessité de reconstructions tissulaires élaborées afin de restaurer la ou les dents extraite(s). Cet exposé vise à évaluer le bénéfice des gestions des alvéoles d’extraction avec l’utilisation de biomatériaux et de la chirurgie muquo-gingivale, afin de limiter les pertes tissulaires post- extractionnelles. Les principes biologiques de ce protocole seront décrits par le biais des résultats des études cliniques réalisées au seins de notre université, et illustré par des cas cliniques. [less ▲]

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See detailPreserving and exhibiting contemporary art. Creation of a Research Unit at the University of Liège
Bawin, Julie ULg

in revue électronique "Ceroart" (conservation, exposition, restauration d'objets d'art) (2007)

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See detailPreserving the morphology and evaluating the quality of liver grafts by hypothermic machine perfusion: A proof-of-concept study using discarded human livers.
Monbaliu, Diethard; Liu, Qiang; Libbrecht, Louis et al

in Liver Transplantation (2012), 18(12), 1495-507

The wider use of livers from expanded criteria donors and donation after circulatory death donors may help to improve access to liver transplantation. A prerequisite for safely using these higher risk ... [more ▼]

The wider use of livers from expanded criteria donors and donation after circulatory death donors may help to improve access to liver transplantation. A prerequisite for safely using these higher risk livers is the development of objective criteria for assessing their condition before transplantation. Compared to simple cold storage, hypothermic machine perfusion (HMP) provides a unique window for evaluating liver grafts between procurement and transplantation. In this proof-of-concept study, we tested basic parameters during HMP that may reflect the condition of human liver grafts, and we assessed their morphology after prolonged HMP. Seventeen discarded human livers were machine-perfused. Eleven livers were nontransplantable (major absolute contraindications and severe macrovesicular steatosis in the majority of the cases). Six livers were found in retrospect to be transplantable but could not be allocated and served as controls. Metabolic parameters (pH, lactate, partial pressure of oxygen, and partial pressure of carbon dioxide), enzyme release in the perfusate [aspartate aminotransferase (AST) and lactate dehydrogenase (LDH)], and arterial/portal resistances were monitored during HMP. Nontransplantable livers released more AST and LDH than transplantable livers. In contrast, arterial/portal vascular resistances and metabolic profiles did not differ between the 2 groups. Morphologically, transplantable livers remained well preserved after 24 hours of HMP. In conclusion, HMP preserves the morphology of human livers for prolonged periods. A biochemical analysis of the perfusate provides information reflecting the extent of the injury endured. Liver Transpl, 2012. (c) 2012 AASLD. [less ▲]

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See detailPrésidence
Bourgeois, Marc ULg

Conference (2010, January 28)

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See detailPrésidence belge et visibilité en matière de défense dans l'environnement d'une armée en réforme
Dumoulin, André ULg

in Pyramides : Revue du Laboratoire d’Etudes et de Recherches en Administration Publique (2011), (21),

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See detailPrésidence du 3ème atelier du colloque international "Boucle et répétition"
Delville, Michel ULg

Diverse speeche and writing (2011)

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See detailPrésident de l’atelier "The History of Experiment"
Delville, Michel ULg

Diverse speeche and writing (2005)

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See detailPrésident de la journée d’études Olith (“Literaire Dynamiek – Atelier 3“)
Delville, Michel ULg

Diverse speeche and writing (2007)

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See detailPrésident de la session "On and Around Rosmarie Waldrop"
Delville, Michel ULg

Diverse speeche and writing (1999)

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See detailPrésident de la session "Salman Rushdie"
Delville, Michel ULg

Diverse speeche and writing (2000)

Detailed reference viewed: 8 (3 ULg)