References of "Neuroimage"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailNeural networks involved in self-judgement in young and elderly adults
Feyers, Dorothée ULg; Collette, Fabienne ULg; D'Argembeau, Arnaud ULg et al

in NeuroImage (2010)

Recent studies have shown that both young and elderly subjects activate the ventromedial prefrontal cortex (VMPFC) when they make self-referential judgements. However, the VMPFC might interact with ... [more ▼]

Recent studies have shown that both young and elderly subjects activate the ventromedial prefrontal cortex (VMPFC) when they make self-referential judgements. However, the VMPFC might interact with different brain regions during self-referencing in the two groups. In this study, based on data from Ruby et al (2009), we have explored this issue using psychophysiological interaction analyses. Young and elderly participants had to judge adjectives describing personality traits in reference to the self versus a close friend or relative (the other), taking either a first-person or a third-person perspective. The physiological factor was the VMPFC activity observed in all participants during self judgement, and the psychological factor was the self versus other referential process. The main effect of first-person perspective in both groups revealed that the VMPFC was coactivated with the left parahippocampal gyrus and the precuneus for self versus other judgments. The main effect of age showed a stronger correlation between activity in the VMPFC and the lingual gyrus in young compared to elderly subjects. Finally, in the interaction, the VMPFC was specifically co-activated with the orbitofrontal gyrus and the precentral gyrus when elderly subjects took a first-person perspective for self judgements. No significant result was observed for the interaction in young subjects. These findings show that, although the VMPFC is engaged by both young and older adults when making self-referential judgements, this brain structure interacts differently with other brain regions as a function of age and perspective. These differences might reflect a tendency by older people to engage in more emotional/social processing than younger adults when making self-referential judgements with a first-person perspective [less ▲]

Detailed reference viewed: 60 (16 ULg)
Full Text
Peer Reviewed
See detailImproved shimming for fMRI specifically optimizing the local BOLD sensitivity
Balteau, Evelyne ULg; Hutton, Chloe; Weiskopf, Nikolaus

in NeuroImage (2010), 49

In functional MRI, magnetic field inhomogeneities due to air-tissue susceptibility differences may lead to severe signal dropouts and geometric distortions in echo-planar images. Therefore, the ... [more ▼]

In functional MRI, magnetic field inhomogeneities due to air-tissue susceptibility differences may lead to severe signal dropouts and geometric distortions in echo-planar images. Therefore, the inhomogeneities in the field are routinely minimized by shimming prior to imaging. However in fMRI, the Blood Oxygen Level Dependent (BOLD) effect is the measure of interest, so the BOLD sensitivity (BS) should be optimized rather than the magnetic field homogeneity. The analytical expression for an estimate of the BOLD sensitivity has been recently developed, allowing for the computation of BOLD sensitivity maps from echo-planar images and field maps. This report describes a novel shimming procedure that optimizes the local BOLD sensitivity over a region of interest. The method is applied in vivo and compared to a standard global shimming procedure. A breath-holding experiment was carried out and demonstrated that the BS-based shimming significantly improved the detection of activation in a target region of interest, the medial orbitofrontal cortex. [less ▲]

Detailed reference viewed: 21 (1 ULg)
Full Text
Peer Reviewed
See detailSleep spindles and neural activity changes in the cortico-striatal system underlie motor sequence consolidation
Barakat, M; Carrier, J; Debas, K et al

in NeuroImage (2010), 51(Suppl. 1),

Detailed reference viewed: 15 (1 ULg)
Full Text
Peer Reviewed
See detailRobustness of optimal design of fMRI experiments with application of a genetic algorithm.
Maus, Bärbel ULg; van Breukelen, Gerard J P; Goebel, Rainer et al

in NeuroImage (2010), 49(3), 2433-2443

In this paper we apply the genetic algorithm developed by Kao et al. (2009) to find designs which are robust against misspecification of the error autocorrelation. Two common optimality criteria, the A ... [more ▼]

In this paper we apply the genetic algorithm developed by Kao et al. (2009) to find designs which are robust against misspecification of the error autocorrelation. Two common optimality criteria, the A-optimality criterion and the D-optimality criterion, based upon a general linear model are employed to obtain locally optimal designs for a given value of the autocorrelation. The maximin criterion is then used to obtain designs which are robust against misspecification of the autocorrelation. Furthermore, robustness depending on the choice of optimality criterion is evaluated. We show analytically and empirically that the A- and D-optimality criterion will result in different optimal designs, e.g. with different stimulus frequencies. Optimal stimulus frequency for the A-optimality criterion has been derived by Liu et al. (2004) whereas we derive here the optimal stimulus frequency for the D-optimality criterion. Conclusions about the robustness of an optimal design against misspecification of model parameters and choice of optimality criterion are drawn based upon our results. [less ▲]

Detailed reference viewed: 12 (3 ULg)
Full Text
Peer Reviewed
See detailEvidence for a role of sleep in forgetting of irrelevant information
Collette, Fabienne ULg; Rauchs, Géraldine; Landeau, Brigitte et al

in NeuroImage (2009, June), 47(Suppl 1), 328-

Detailed reference viewed: 20 (1 ULg)
Full Text
Peer Reviewed
See detailPain and non-pain processing during hypnosis: a thulium-YAG event-related fMRI study.
Vanhaudenhuyse, Audrey ULg; Boly, Mélanie ULg; Balteau, Evelyne ULg et al

in NeuroImage (2009), 47(3), 1047-54

The neural mechanisms underlying the antinociceptive effects of hypnosis still remain unclear. Using a parametric single-trial thulium-YAG laser fMRI paradigm, we assessed changes in brain activation and ... [more ▼]

The neural mechanisms underlying the antinociceptive effects of hypnosis still remain unclear. Using a parametric single-trial thulium-YAG laser fMRI paradigm, we assessed changes in brain activation and connectivity related to the hypnotic state as compared to normal wakefulness in 13 healthy volunteers. Behaviorally, a difference in subjective ratings was found between normal wakefulness and hypnotic state for both non-painful and painful intensity-matched stimuli applied to the left hand. In normal wakefulness, non-painful range stimuli activated brainstem, contralateral primary somatosensory (S1) and bilateral insular cortices. Painful stimuli activated additional areas encompassing thalamus, bilateral striatum, anterior cingulate (ACC), premotor and dorsolateral prefrontal cortices. In hypnosis, intensity-matched stimuli in both the non-painful and painful range failed to elicit any cerebral activation. The interaction analysis identified that contralateral thalamus, bilateral striatum and ACC activated more in normal wakefulness compared to hypnosis during painful versus non-painful stimulation. Finally, we demonstrated hypnosis-related increases in functional connectivity between S1 and distant anterior insular and prefrontal cortices, possibly reflecting top-down modulation. [less ▲]

Detailed reference viewed: 146 (30 ULg)
Full Text
Peer Reviewed
See detailAbnormal neural filtering of irrelevant visual information in depression
Desseilles, Martin ULg; Balteau, Evelyne ULg; Sterpenich, Virginie et al

in NeuroImage (2009), 45(Suppl. 1),

Detailed reference viewed: 23 (7 ULg)
Full Text
Peer Reviewed
See detailComputational biology — Modeling of primary blast effects on the central nervous system
Moore, David; Jérusalem, Antoine; Nyen, Michelle et al

in NeuroImage (2009), 47(Sup. 2), 10-20

Objectives Recent military conflicts in Iraq and Afghanistan have highlighted the wartime effect of traumatic brain injury. The reason for the prominence of TBI in these particular conflicts as opposed to ... [more ▼]

Objectives Recent military conflicts in Iraq and Afghanistan have highlighted the wartime effect of traumatic brain injury. The reason for the prominence of TBI in these particular conflicts as opposed to others is unclear but may result from the increased survivability of blast due to improvements in body armor. In the military context blunt, ballistic and blast effects may all contribute to CNS injury, however blast in particular, has been suggested as a primary cause of military TBI. While blast effects on some biological tissues, such as the lung, are documented in term of injury thresholds, this is not the case for the CNS. We hypothesized that using bio-fidelic models, allowing for fluid-solid interaction and basic material properties available in the literature, that a blast wave would interact with CNS tissue and cause a possible concussive effect. Methods The blast shockwave on CNS tissue was modeled using a coupled computational fluid-solid dynamic simulation. The model included a complex finite element mesh of the head and intra-cranial contents. The effects of threshold and 50% lethal blast lung injury were compared with concussive impact injury using the full head model allowing know upper and lower bounds of tissue injury to be applied using pulmonary injury as the reference tissue. Results The effects of a 50% lethal dose blast lung injury (LD50) were comparable with concussive impact injury using the DVBIC – MIT full head model. Interpretation CNS blast concussive effects were found to be similar between impact mild TBI and the blast field associated with LD50 lung blast injury sustained without personal protective equipment. With the ubiquitous use of personal protective equipment this suggests that blast concussive effects may more readily occur in personnel due to enhanced survivability in the current conflicts. [less ▲]

Detailed reference viewed: 108 (16 ULg)
Full Text
Peer Reviewed
See detailRejection of pulse related artefact (PRA) from continuous electroencephalographic (EEG) time series recorded during functional magnetic resonance imaging (fMRI) using constraint independent component analysis (cICA).
Leclercq, Yves ULg; Balteau, Evelyne ULg; Dang Vu, Thien Thanh ULg et al

in NeuroImage (2009), 44(3), 679-91

Rejection of the pulse related artefact (PRA) from electroencephalographic (EEG) time series recorded simultaneously with fMRI data is difficult, particularly during NREM sleep because of the similarities ... [more ▼]

Rejection of the pulse related artefact (PRA) from electroencephalographic (EEG) time series recorded simultaneously with fMRI data is difficult, particularly during NREM sleep because of the similarities between sleep slow waves and PRA, in both temporal and frequency domains and the need to work with non-averaged data. Here we introduce an algorithm based on constrained independent component analysis (cICA) for PRA removal. This method has several advantages: (1) automatic detection of the components corresponding to the PRA; (2) stability of the solution and (3) computational treatability. Using multichannel EEG recordings obtained in a 3 T MR scanner, with and without concomitant fMRI acquisition, we provide evidence for the sensitivity and specificity of the method in rejecting PRA in various sleep and waking conditions. [less ▲]

Detailed reference viewed: 25 (4 ULg)
Full Text
Peer Reviewed
See detailOptimization of blocked designs in fMRI studies
Maus, Bärbel ULg; Van Breukelen, G.J.P; Goebel, R. et al

in NeuroImage (2009), 47(Supplement 1), 125

Detailed reference viewed: 14 (3 ULg)
Full Text
Peer Reviewed
See detailNeural correlates mediating the consolidation of visuomotor adapted actions : A study on the role of night sleep versus the passage of daytime
Debas, Karen; Carrier, Julie; Orban, Pierre et al

in NeuroImage (2009), 45(Suppl. 1),

Detailed reference viewed: 14 (0 ULg)
Full Text
Peer Reviewed
See detailSelecting forward models for MEG source-reconstruction using model-evidence.
Henson, R. N.; Mattout, J.; Phillips, Christophe ULg et al

in NeuroImage (2009), 46(1), 168-76

We investigated four key aspects of forward models for distributed solutions to the MEG inverse problem: 1) the nature of the cortical mesh constraining sources (derived from an individual's MRI, or ... [more ▼]

We investigated four key aspects of forward models for distributed solutions to the MEG inverse problem: 1) the nature of the cortical mesh constraining sources (derived from an individual's MRI, or inverse-normalised from a template mesh); 2) the use of single-sphere, overlapping spheres, or Boundary Element Model (BEM) head-models; 3) the density of the cortical mesh (3000 vs. 7000 vertices); and 4) whether source orientations were constrained to be normal to that mesh. These were compared within the context of two types of spatial prior on the sources: a single prior corresponding to a standard L2-minimum-norm (MNM) inversion, or multiple sparse priors (MSP). The resulting generative models were compared using a free-energy approximation to the Bayesian model-evidence after fitting multiple epochs of responses to faces or scrambled faces. Statistical tests of the free-energy, across nine participants, showed clear superiority of MSP over MNM models; with the former reconstructing deeper sources. Furthermore, there was 1) no evidence that an individually-defined cortical mesh was superior to an inverse-normalised canonical mesh, but 2) clear evidence that a BEM was superior to spherical head-models, provided individually-defined inner skull and scalp meshes were used. Finally, for MSP models, there was evidence that the combination of 3) higher density cortical meshes and 4) dipoles constrained to be normal to the mesh was superior to lower-density or freely-oriented sources (in contrast to the MNM models, in which free-orientation was optimal). These results have practical implications for MEG source reconstruction, particularly in the context of group studies. [less ▲]

Detailed reference viewed: 17 (0 ULg)
Full Text
Peer Reviewed
See detailNeural Correlates of Envisioning Emotional Events in the near and Far Future
D'Argembeau, Arnaud ULg; Xue, Gui; Lu, Zhong-Lin et al

in NeuroImage (2008), 40(1), 398-407

Being able to envision emotional events that might happen in the future has a clear adaptive value. This study addressed the functional neuroanatomy of this process and investigated whether it is ... [more ▼]

Being able to envision emotional events that might happen in the future has a clear adaptive value. This study addressed the functional neuroanatomy of this process and investigated whether it is modulated by temporal distance. Participants imagined positive and negative events pertaining to the near future or far future while their brain activity was measured with fMRI. The results demonstrate that the anterior part of the ventromedial prefrontal cortex (vmPFC) was more active in envisioning emotional events in the far future than in the near future, whereas the caudate nucleus was engaged in envisioning emotional (especially positive) situations in the near future. We argue that the anterior part of the vmPFC might assign emotional values to mental representations of future events that pertain to long-term goals. On the other hand, the caudate might support more concrete simulations of action plans to achieve rewarding situations in the near future. [less ▲]

Detailed reference viewed: 79 (7 ULg)
Full Text
Peer Reviewed
See detailVariational Bayesian inversion of the equivalent current dipole model in EEG/MEG
Kiebel, S. J.; Daunizeau, J.; Phillips, Christophe ULg et al

in Neuroimage (2008), 39(2), 728-741

In magneto- and electroencephalography (M/EEG), spatial modelling of sensor data is necessary to make inferences about underlying brain activity. Most source reconstruction techniques belong to one of two ... [more ▼]

In magneto- and electroencephalography (M/EEG), spatial modelling of sensor data is necessary to make inferences about underlying brain activity. Most source reconstruction techniques belong to one of two approaches: point source models, which explain the data with a small number of equivalent current dipoles and distributed source or imaging models, which use thousands of dipoles. Much methodological research has been devoted to developing sophisticated Bayesian source imaging inversion schemes, while dipoles have received less such attention. Dipole models have their advantages; they are often appropriate summaries of evoked responses or helpful first approximations. Here, we propose a variational Bayesian algorithm that enables the fast Bayesian inversion of dipole models. The approach allows for specification of priors on all the model parameters. The posterior distributions can be used to form Bayesian confidence intervals for interesting parameters, like dipole locations. Furthermore, competing models (e.g., models with different numbers of dipoles) can be compared using their evidence or marginal likelihood. Using synthetic data, we found the scheme provides accurate dipole localizations. We illustrate the advantage of our Bayesian scheme, using a multi-subject EEG auditory study, where we compare competing models for the generation of the N100 component. (C) 2007 Elsevier Inc. All rights reserved. [less ▲]

Detailed reference viewed: 26 (2 ULg)
Full Text
Peer Reviewed
See detailNeural networks for short-term memory for order differentiate high and low proficiency bilinguals
Majerus, Steve ULg; Belayachi, Sanaa ULg; De Smedt, Bert et al

in NeuroImage (2008), 42

Detailed reference viewed: 139 (30 ULg)
Full Text
Peer Reviewed
See detailChronotype-dependent performance modulation according to time of day : a functional neuroimaging approach
Schmidt, Christina ULg; Collette, Fabienne ULg; Sterpenich, Virginie et al

in NeuroImage (2008), 41(Suppl. 1),

Detailed reference viewed: 23 (1 ULg)
Full Text
Peer Reviewed
See detailA three-dimensional MRI atlas of the zebra finch brain in stereotaxic coordinates.
Poirier, Colline; Vellema, Michiel; Verhoye, Marleen et al

in NeuroImage (2008), 41(1), 1-6

The neurobiology of birdsong, as a model for human speech, is a fast growing area of research in the neurosciences and involves electrophysiological, histological and more recently magnetic resonance ... [more ▼]

The neurobiology of birdsong, as a model for human speech, is a fast growing area of research in the neurosciences and involves electrophysiological, histological and more recently magnetic resonance imaging (MRI) approaches. Many of these studies require the identification and localization of different brain areas (nuclei) involved in the sensory and motor control of song. Until now, the only published atlases of songbird brains consisted in drawings based on histological slices of the canary and of the zebra finch brain. Taking advantage of high-magnetic field (7 Tesla) MRI technique, we present the first high-resolution (80 x 160 x 160 microm) 3-D digital atlas in stereotaxic coordinates of a male zebra finch brain, the most widely used species in the study of birdsong neurobiology. Image quality allowed us to discern most of the song control, auditory and visual nuclei. The atlas can be freely downloaded from our Web site and can be interactively explored with MRIcro. This zebra finch MRI atlas should become a very useful tool for neuroscientists working on birdsong, especially for co-registrating MRI data but also for determining accurately the optimal coordinates and angular approach for injections or electrophysiological recordings. [less ▲]

Detailed reference viewed: 78 (2 ULg)
Full Text
Peer Reviewed
See detailStriatal Contribution to sleep-dependent motor consolidation
Debas, Karen; Carrier, Julie; Orban, Pierre et al

in NeuroImage (2008), 41(Suppl. 1),

Detailed reference viewed: 22 (1 ULg)