References of "Maquet, Pierre"
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See detailActive brain processes during human quiescent sleep
Dang Vu, Thien Thanh ULg; Schabus, M.; Balteau, Evelyne ULg et al

in Journal of Sleep Research (2006, September), 15(Suppl. 1), 51

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See detailNeural correlates of sleep spindles as revealed by simultaneous electroencephalography (EEG) and functional magnetic resonance imaging (FMRI)
Schabus, M.; Dang-Vu, T.; Balteau, Evelyne ULg et al

in Journal of Sleep Research (2006, September), 15(Suppl. 1), 50-51

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See detailThe role of sleep in motor memory consolidation assessed by fMRI
Albouy, Geneviève ULg; Sterpenich, Virginie ULg; Darsaud, A. et al

in Journal of Sleep Research (2006, September), 15(Suppl. 1), 189

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See detailSleep-dependent changes in brain activity subserving human navigation
Rauchs, G.; Orban, Pierre ULg; Schmidt, Christina ULg et al

in Journal of Sleep Research (2006, September), 15(Suppl. 1), 189-190

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See detailThe locus ceruleus is involved in the successful retrieval of emotional memories in humans
Sterpenich, Virginie ULg; D'Argembeau, Arnaud ULg; Desseilles, Martin ULg et al

in Journal of Neuroscience (2006), 26(28), 7416-7423

Emotional memories are better remembered than neutral ones. The amygdala is involved in this enhancement not only by modulating the hippocampal activity, but possibly also by modulating central arousal ... [more ▼]

Emotional memories are better remembered than neutral ones. The amygdala is involved in this enhancement not only by modulating the hippocampal activity, but possibly also by modulating central arousal. Using functional magnetic resonance imaging, we analyzed the retrieval of neutral faces encoded in emotional or neutral contexts. The pupillary size measured during encoding was used as a modulator of brain responses during retrieval. The interaction between emotion and memory showed significant responses in a set of areas, including the amygdala and parahippocampal gyrus. These areas responded significantly more for correctly remembered faces encoded in an emotional, compared with neutral, context. The same interaction conducted on responses modulated by the pupillary size revealed an area of the dorsal tegmentum of the ponto-mesencephalic region, consistent with the locus ceruleus. Moreover, a psychophysiological interaction showed that amygdalar responses were more tightly related to those of the locus ceruleus when remembering faces that had been encoded in an emotional, rather than neutral, context. These findings suggest that the restoration of a central arousal similar to encoding takes part in the successful retrieval of neutral events learned in an emotional context. [less ▲]

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See detailTracking the recovery of consciousness from coma
Laureys, Steven ULg; Boly, Mélanie ULg; Maquet, Pierre ULg

in Journal of Clinical Investigation (2006), 116(7), 1823-1825

Predicting the chances of recovery of consciousness and communication in patients who survive their coma but transit in a vegetative state or minimally conscious state (MCS) remains a major challenge for ... [more ▼]

Predicting the chances of recovery of consciousness and communication in patients who survive their coma but transit in a vegetative state or minimally conscious state (MCS) remains a major challenge for their medical caregivers. Very few studies have examined the slow neuronal changes underlying functional recovery of consciousness from severe chronic brain damage. A case study in this issue of the JCI reports an extraordinary recovery of functional verbal communication and motor function in a patient who remained in MCS for 19 years (see the related article beginning on page 2005). Diffusion tensor MRI showed increased fractional anisotropy (assumed to reflect myelinated fiber density) in posteromedial cortices, encompassing cuneus and precuneus. These same areas showed increased glucose metabolism as studied by PET scanning, likely reflecting the neuronal regrowth paralleling the patient's clinical recovery. This case shows that old dogmas need to be oppugned, as recovery with meaningful reduction in disability continued in this case for nearly 2 decades after extremely severe traumatic brain injury. [less ▲]

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See detailImplicit oculomotor sequence learning in humans: Time course of offline processing
Albouy, Geneviève ULg; Ruby, P.; Phillips, Christophe ULg et al

in Brain Research (2006), 1090

Studies of manual and digital sequence learning indicate that motor memories continue to be processed after training has ended, following a succession of identifiable steps. However, it is not known ... [more ▼]

Studies of manual and digital sequence learning indicate that motor memories continue to be processed after training has ended, following a succession of identifiable steps. However, it is not known whether this offline memory processing constitutes a basic feature of motor learning and generalizes to the implicit learning of a sequence of eye movements. To assess this hypothesis, we have created the serial oculomotor reaction time task (SORT). Participants were trained to the SORT then tested after either 30 min, 5 h or 24 h. During training, ocular reaction times decreased monotonically over practice of a repeated sequence, then increased when a different sequence was displayed, demonstrating oculomotor learning of the trained sequence. When tested 30 min after training, a significant gain in oculomotor performance was observed irrespective of the sequence learning. This gain was no longer present after 5 h. Remarkably, a gain in performance specific to the learned sequence emerged only 24 h after training. After testing, a generation task confirmed that most subjects learned implicitly the regularities of the sequence. Our results show that, as for manual or digital sequences, oculomotor sequences can be implicitly learned. The offline processing of oculomotor memories follows distinct stages in a way similar to those observed after manual or digital sequence learning. (c) 2006 Elsevier B.V. All rights reserved. [less ▲]

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See detailSleep after spatial learning promotes covert reorganization of brain activity
Orban, Pierre ULg; Rauchs, Géraldine; Balteau, Evelyne ULg et al

in Proceedings of the National Academy of Sciences of the United States of America (2006), 103(18), 7124-7129

Sleep promotes the integration of recently acquired spatial memories into cerebral networks for the long term. In this study, we examined how sleep deprivation hinders this consolidation process. Using ... [more ▼]

Sleep promotes the integration of recently acquired spatial memories into cerebral networks for the long term. In this study, we examined how sleep deprivation hinders this consolidation process. Using functional MRI, we mapped regional cerebral activity during place-finding navigation in a virtual town, immediately after learning and 3 days later, in subjects either allowed regular sleep (RS) or totally sleep-deprived (TSD) on the first posttraining night. At immediate and delayed retrieval, place-finding navigation elicited increased brain activity in an extended hippocamponeocortical network in both RS and TSD subjects. Behavioral performance was equivalent between groups. However, striatal navigation-related activity increased more at delayed retrieval in RS than in TSD subjects. Furthermore, correlations between striatal response and behavioral performance, as well as functional connectivity between the striatum and the hippocampus, were modulated by posttraining sleep. These data suggest that brain activity is restructured during sleep in such a way that navigation in the virtual environment, initially related to a hippocampus-dependent spatial strategy, becomes progressively contingent in part on a response-based strategy mediated by the striatum. Both neural strategies eventually relate to equivalent performance levels, indicating that covert reorganization of brain patterns underlying navigation after sleep is not necessarily accompanied by overt changes in behavior. [less ▲]

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See detailOffline persistence of memory-related cerebral activity during active wakefulness
Peigneux, Philippe ULg; Orban, Pierre ULg; Balteau, Evelyne ULg et al

in PLoS Biology (2006), 4(4), 100

Much remains to be discovered about the fate of recent memories in the human brain. Several studies have reported the reactivation of learning-related cerebral activity during post-training sleep ... [more ▼]

Much remains to be discovered about the fate of recent memories in the human brain. Several studies have reported the reactivation of learning-related cerebral activity during post-training sleep, suggesting that sleep plays a role in the offline processing and consolidation of memory. However, little is known about how new information is maintained and processed during post-training wakefulness before sleep, while the brain is actively engaged in other cognitive activities. We show, using functional magnetic resonance imaging, that brain activity elicited during a new learning episode modulates brain responses to an unrelated cognitive task, during the waking period following the end of training. This post-training activity evolves in learning-related cerebral structures, in which functional connections with other brain regions are gradually established or reinforced. It also correlates with behavioral performance. These processes follow a different time course for hippocampus-dependent and hippocampus-independent memories. Our experimental approach allowed the characterization of the offline evolution of the cerebral correlates of recent memories, without the confounding effect of concurrent practice of the learned material. Results indicate that the human brain has already extensively processed recent memories during the first hours of post-training wakefulness, even when simultaneously coping with unrelated cognitive demands. [less ▲]

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See detailImproved PRESS sequence for lactate detection in the human vitreous body
Balteau, Evelyne ULg; COLLIGNON, Nathalie ULg; Robe, Pierre ULg et al

in Proceedings of the International Society for Magnetic Resonance in Medicine (2006), 14

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See detailHippocampal response at training promotes insight after sleep
Darsaud, Annabelle; Balteau, Evelyne ULg; Desseilles, Martin ULg et al

in NeuroImage (2006), 31(Suppl. 1),

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See detailThe role of sleep in the consolidation of emotional memories in humans : a fMRI study
Sterpenich, Virginie; Albouy, Geneviève ULg; Boly, Mélanie ULg et al

Poster (2006)

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See detailEarly boost and slow consolidation in motor skill learning
Hotermans, C.; Peigneux, Philippe ULg; Maertens De Noordhout, Alain ULg et al

in Learning & Memory (Cold Spring Harbor, N.Y.) (2006), 13(5, Sep-Oct), 580-583

Motorskill learning is a dynamic process that continues covertly after training has ended and eventually leads to delayed increments in performance. Current theories Suggest that this off-line improvement ... [more ▼]

Motorskill learning is a dynamic process that continues covertly after training has ended and eventually leads to delayed increments in performance. Current theories Suggest that this off-line improvement takes time and appears only after several hours. Here we show an early transient and short-lived boost in performance, emerging as early as 5-30 min after training but no longer observed 4 h later. This early boost is predictive of the performance achieved 48 h later, Suggesting its functional relevance for memory processes. [less ▲]

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See detailThe left intraparietal sulcus and verbal short-term memory: Focus of attention or serial order ?
Majerus, Steve ULg; Poncelet, Martine ULg; Van der Linden, Martial ULg et al

in Neuroimage (2006), 32(2), 880-891

One of the most consistently activated regions during verbal short-term memory (STM) tasks is the left intraparietal sulcus (IPS). However, its precise role remains a matter of debate. While some authors ... [more ▼]

One of the most consistently activated regions during verbal short-term memory (STM) tasks is the left intraparietal sulcus (IPS). However, its precise role remains a matter of debate. While some authors consider the IPS to be a specific store for serial order information, other data suggest that it serves a more general function of attentional focalization. In the current fMRI experiment, we investigated these two hypotheses by presenting different verbal STM conditions that probed recognition for word identity or word order and by assessing functional connectivity of the left IPS with distant brain areas. If the IPS has a role of attentional focalization, then it should be involved in both order and item conditions, but it should be connected to different brain regions, depending on the neural substrates involved in processing the different types of information (order versus phonological/orthographic) to be remembered in the item and order STM conditions. We observed that the left IPS was activated in both order and item STM conditions but for different reasons: during order STM, the left IPS was functionally connected to serial/temporal order processing areas in the right IPS, premotor and cerebellar cortices, while during item STM, the left IPS was connected to phonological and orthographic processing areas in the superior temporal and fusiform gyri. Our data support a position considering that the left IPS acts as an attentional modulator of distant neural networks which themselves are specialized in processing order or language representations. More generally, they strengthen attention-based accounts of verbal STM. [less ▲]

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See detailA role for sleep in brain plasticity.
Dang Vu, Thien Thanh ULg; Desseilles, Martin ULg; Peigneux, Philippe ULg et al

in Pediatric Rehabilitation (2006), 9(2), 98-118

The idea that sleep might be involved in brain plasticity has been investigated for many years through a large number of animal and human studies, but evidence remains fragmentary. Large amounts of sleep ... [more ▼]

The idea that sleep might be involved in brain plasticity has been investigated for many years through a large number of animal and human studies, but evidence remains fragmentary. Large amounts of sleep in early life suggest that sleep may play a role in brain maturation. In particular, the influence of sleep in developing the visual system has been highlighted. The current data suggest that both Rapid Eye Movement (REM) and non-REM sleep states would be important for brain development. Such findings stress the need for optimal paediatric sleep management. In the adult brain, the role of sleep in learning and memory is emphasized by studies at behavioural, systems, cellular and molecular levels. First, sleep amounts are reported to increase following a learning task and sleep deprivation impairs task acquisition and consolidation. At the systems level, neurophysiological studies suggest possible mechanisms for the consolidation of memory traces. These imply both thalamocortical and hippocampo-neocortical networks. Similarly, neuroimaging techniques demonstrated the experience-dependent changes in cerebral activity during sleep. Finally, recent works show the modulation during sleep of cerebral protein synthesis and expression of genes involved in neuronal plasticity. [less ▲]

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See detailA prominent role for amygdaloid complexes in the Variability in Heart Rate (VHR) during Rapid Eye Movement (REM) sleep relative to wakefulness.
Desseilles, Martin ULg; Dang Vu, Thien Thanh ULg; Laureys, Steven ULg et al

in NeuroImage (2006), 32(3), 1008-1015

Rapid eye movement sleep (REMS) is associated with intense neuronal activity, rapid eye movements, muscular atonia and dreaming. Another important feature in REMS is the instability in autonomic ... [more ▼]

Rapid eye movement sleep (REMS) is associated with intense neuronal activity, rapid eye movements, muscular atonia and dreaming. Another important feature in REMS is the instability in autonomic, especially in cardiovascular regulation. The neural mechanisms underpinning the variability in heart rate (VHR) during REMS are not known in detail, especially in humans. During wakefulness, the right insula has frequently been reported as involved in cardiovascular regulation but this might not be the case during REMS. We aimed at characterizing the neural correlates of VHR during REMS as compared to wakefulness and to slow wave sleep (SWS), the other main component of human sleep, in normal young adults, based on the statistical analysis of a set of (H2O)-O-15 positron emission tomography (PET) sleep data acquired during SWS, REMS and wakefulness. The results showed that VHR correlated more tightly during REMS than during wakefulness with the rCBF in the right amygdaloid complex. Moreover, we assessed whether functional relationships between amygdala and any brain area changed depending the state of vigilance. Only the activity within in the insula was found to covary with the amygdala, significantly more tightly during wakefulness than during REMS in relation to the VHR. The functional connectivity between the amygdala and the insular cortex, two brain areas involved in cardiovascular regulation, differs significantly in REMS as compared to wakefulness. This suggests a functional reorganization of central cardiovascular regulation during REMS. (c) 2006 Elsevier Inc. All rights reserved. [less ▲]

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See detailDaytime light exposure dynamically enhances brain responses.
Vandewalle, Gilles ULg; Balteau, Evelyne ULg; Phillips, Christophe ULg et al

in Current Biology (2006), 16(16), 1616-21

In humans, light enhances both alertness and performance during nighttime and daytime [1-4] and influences regional brain function [5]. These effects do not correspond to classical visual responses but ... [more ▼]

In humans, light enhances both alertness and performance during nighttime and daytime [1-4] and influences regional brain function [5]. These effects do not correspond to classical visual responses but involve a non-image forming (NIF) system, which elicits greater endocrine, physiological, neurophysiological, and behavioral responses to shorter light wavelengths than to wavelengths geared toward the visual system [6-11]. During daytime, the neural changes induced by light exposure, and their time courses, are largely unknown. With functional magnetic resonance imaging (fMRI), we characterized the neural correlates of the alerting effect of daytime light by assessing the responses to an auditory oddball task [12-15], before and after a short exposure to a bright white light. Light-induced improvement in subjective alertness was linearly related to responses in the posterior thalamus. In addition, light enhanced responses in a set of cortical areas supporting attentional oddball effects, and it prevented decreases of activity otherwise observed during continuous darkness. Responses to light were remarkably dynamic. They declined within minutes after the end of the light stimulus, following various region-specific time courses. These findings suggest that light can modulate activity of subcortical structures involved in alertness, thereby dynamically promoting cortical activity in networks involved in ongoing nonvisual cognitive processes. [less ▲]

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See detailBrain response to one's own name in vegetative state, minimally conscious state and locked-in syndrome
Perrin, F.; Schnakers, Caroline ULg; Schabus, M. et al

in Archives of Neurology (2006), 63

Detailed reference viewed: 35 (7 ULg)