Guy Cheron

Université Libre de Bruxelles | ULB · Laboratoire des Sciences de la Motricité

Objective To investigate kinematic and muscle activity differences during the sleep-push movement in elite field hockey players. We hypothesized that players with specialized sleep-push movement training (specialists) would possess a lower center of mass (CoM) and enhanced reproducibility of muscle activations during the movement, compared to playe...

Electroencephalography (EEG) can detect changes in cerebral activity during spaceflight. This study evaluates the effect of spaceflight on brain networks through analysis of the Default Mode Network (DMN)'s alpha frequency band power and functional connectivity (FC), and the persistence of these changes. Five astronauts' resting state EEGs under th...

The network formed by the brainstem, cerebellum, and hippocampus occupies a central position to achieve navigation. Multiple physiological functions are implicated in this complex behavior. Among these, control of the eye-head and body movements is crucial. The gaze-holding system realized by the brainstem oculomotor neural integrator (ONI) situate...

The cognitive performance of the crew has a major impact on mission safety and success in space flight. Monitoring of cognitive performance during long-duration space flight therefore is of paramount importance and can be performed using compact state-of-the-art mobile EEG. However, signal quality of EEG may be compromised due to the vicinity to va...

Background: Accidental awareness during general anesthesia (AAGA) is defined as an unexpected awareness of the patient during general anesthesia. This phenomenon occurs in 1%-2% of high-risk practice patients and can cause physical suffering and psychological after-effects, called posttraumatic stress disorder. In fact, no monitoring techniques are...

The brain is essential to human adaptation to any environment including space. We examined astronauts’ brain function through their electrical EEG brain potential responses related to their decision of executing a docking task in the same virtual scenario in Weightlessness and on Earth before and after the space stay of 6 months duration. Astronaut...

The search for the best wellness practice has promoted the development of devices integrating different technologies and guided meditation. However, the final effects on the electrical activity of the brain remain relatively sparse. Here, we have analyzed of the alpha and theta electroencephalographic oscillations during the realization of the arre...

Alzheimer's disease is histopathologically well defined by the presence of amyloid deposits and tau‐related neurofibrillary tangles in crucial regions of the brain. Interest is growing in revealing and determining possible pathological markers also in the cerebellum as its involvement in cognitive functions is now well supported. Despite the centra...

Objective Different visual stimuli are classically used for triggering visual evoked potentials comprising well-defined components linked to the content of the displayed image. These evoked components result from the average of ongoing EEG signals in which additive and oscillatory mechanisms contribute to the component morphology. The evoked relate...

The present study aimed to characterize microstate dynamics induced by non-reactive attention underlying mindfulness. Electroencephalogram signals from eighteen trained meditators and a matched non-meditators group were recorded before, during, and after a non-reactive attention meditation or during three resting periods respectively, while they we...

Résumé En 1992, le Laboratoire de physiologie humaine de l’université de Parme (Italie) publie une étude décrivant, chez le macaque, des neurones « miroirs » s’activant à la fois lorsque le singe réalise une action et lorsqu’il observe un expérimentateur effectuer cette même action. L’équipe de recherche à l’origine de cette découverte postule que...

Although human adaptation to spaceflight has been studied for decades, little is known about its long-term effects on brain and behavior. The present study investigated visuospatial performance and associated electrophysiological responses in astronauts before, during, and after an approximately half-year long mission to the International Space Sta...

Previous studies showed reduced activity of anterior cingulate cortex and supplementary motor area during inhibition in children with attention‐deficit/hyperactivity disorder (ADHD). This study aimed to investigate deep brain generators underlying alterations of evoked potentials components triggered by visual GO/NoGO tasks in children with ADHD co...

Transcranial direct-current stimulation (tDCS) is a non-invasive brain stimulation technique consisting in the application of weak electric currents on the scalp. Although previous studies have demonstrated the clinical value of tDCS for modulating sensory, motor, and cognitive functions, there are still huge gaps in the knowledge of the underlying...

Ce livre s’articule autour de l’idée que les oscillations neuronales du cerveau forment le fondement du mouvement et de la pensée. Il démontre que la majorité des fonctions cérébrales peut être pilotée à partir d’une gamme étendue d’oscillations pouvant produire des états mentaux différents allant de l’éveil au sommeil, au rêve, au passage de la se...

We here studied the possibility that the coordination of the upper limb segments acting on the hand controlling the bow of the violin during a musical performance could be organized in a planar covariation pattern. Two music masters from the Queen Elisabeth Music Chapel of Belgium played the cadence of the first movement of Mozart’s concert symphon...

Non-invasive BMI applications are increasingly used in different contexts ranging from industrial, clinical and gaming. After having tested the difference between a classical EEG recorder with electroconductive gel (ANT system) and the MUSE EEG headband, we studied the BCI performances of the later during the control of a small robot. We demonstrat...

3D augmented reality could provide an improvement of clinical symptomatology in patients suffering from neuropathic unilateral facial pain

Interactions between two brains constitute the essence of social communication. Daily movements are commonly executed during social interactions and are determined by different mental states that may express different positive or negative behavioral intent. In this context, the effective recognition of festive or violent intent before the action ex...

Event-related potentials (ERP) studies report alterations in the ongoing visuo-attentional processes in children with attention-deficit/hyperactivity disorder (ADHD). We hypothesized that the neural generators progressively recruited after a cue stimulus imply executive-related areas well before engagement in executive processing in children with A...

Psychological “flow” emerges from a goal requiring action, and a match between skills and challenge. Using high-density electroencephalographic (EEG) recording, we quantified the neural generators characterizing psychological “flow” compared to a mindful “stress” state during a professional tightrope performance. Applying swLORETA based on self-rep...

Transcranial direct-current stimulation (tDCS) is a non-invasive brain stimulation technique consisting in the application of weak electric currents on the scalp. Although previous studies have demonstrated the clinical value of tDCS for modulating sensory, motor, and cognitive functions, there are still huge gaps in the knowledge of the underlying...

Background Motor deficits in autism have a double aspect: on one side, they are neglected by standard diagnostic procedures, on the other they are very frequent (70%) and promising as early indicator of the syndrome. Their characterization is extremely relevant, as they could impact on social abilities based on the understanding of others’ actions....

Adequate sleep quantity and quality is required to maintain vigilance, cognitive and learning processes. A decrease of sleep quantity preflight and on the International Space Station (ISS) has been reported. Recent counter-measures have been implemented to better regulate sleep opportunities on ISS. In our study, astronauts were allocated enough ti...

The tACS only differs from tDCS by the fact that sinusoidal currents are given at a specific frequency in place of continuous and constant currents. tACS directly modulates oscillatory brain activity in such a way that the stimulation frequency can be adapted to the frequency of the specific targeted oscillation of the brain. Although there is an e...

La neurofisiologia del movimento e dell’apprendimento motorio occupa un ampio campo scientifico. Le basi fondamentali dell’elaborazione centrale del movimento si inseriscono in strutture cerebrali molto specifiche sul piano anatomico e funzionale, ma anche riccamente interconnesse, formando insiemi neuronali gerarchici e dinamici. L’obiettivo princ...

La neurofisiología del movimiento y del aprendizaje motor abarca un campo científico muy amplio. Las bases fundamentales de la elaboración central del movimiento se inscriben en estructuras cerebrales muy específicas desde los puntos de vista anatómico y funcional, pero también profusamente interconectadas, formando conjuntos neuronales jerarquizad...

Purkinje cells (PC) control deep cerebellar nuclei (DCN), which in turn inhibit inferior olive nucleus, closing a positive feedback loop via climbing fibers. PC highly express potassium BK channels but their contribution to the olivo-cerebellar loop is not clear. Using multiple-unit recordings in alert mice we found in that selective deletion of BK...

In contrast to childhood ADHD that is characterized by inattention, impulsivity and hyperactivity, most adults with ADHD predominantly exhibit inattention. We used a new oddball paradigm using implicit navigational images and analysed EEG dynamics with swLORETA inverse modelling of the evoked potential generators to study cortical processing in adu...

We examined proactive (early restraint in preparation for stopping) and reactive (late correction to stop ongoing action) motor response inhibition in two groups of participants: professional athletes (n = 28) and nonathletes (n = 25). We recruited the elite athletes from Belgian national taekwondo and fencing teams. We estimated proactive and reac...

Background: Studies investigating event-related potential (ERP) evoked in a Cue-Go/NoGo paradigm have shown lower frontal N1, N2 and central P3 in children with attention-deficit/hyperactivity disorder (ADHD) compared to typically developing children (TDC). However, the electroencephalographic (EEG) dynamics underlying these ERPs remain largely un...

In order to characterize the neural generators of the brain oscillations related to motor imagery (MI), we investigated the cortical, subcortical, and cerebellar localizations of their respective electroencephalogram (EEG) spectral power and phase locking modulations. The MI task consisted in throwing a ball with the dominant upper limb while in a...

The ability to suppress responses that are inappropriate, as well as the mechanisms monitoring the accuracy of actions in order to compensate for errors, is central to human behavior. Neural alterations that prevent stopping an inaccurate response, combined with a decreased ability of error monitoring, are considered to be prominent features of alc...

This paper describes a study protocol, which aims to explore and describe the feasibility of a mobile-phone application for initiating intuitive eating and intuitive exercising in patients who are following an ambulatory treatment for obesity. Intuitive eating refers to one’s ability to make food choices based on one’s awareness of his/her body's r...

The ecological environment offered by virtual reality is primarily supported by visual information. The different image contents and their rhythmic presentation imply specific bottom-up and top-down processing. Because these processes already occur during passive observation we studied the brain responses evoked by the presentation of specific 3D v...

Brain function is compromised in myotonic dystrophy type 1 (DM1), but the underlying mechanisms are not fully understood. To gain insight into the cellular and molecular pathways primarily affected, we studied a mouse model of DM1 and brains of adult patients. We found pronounced RNA toxicity in the Bergmann glia of the cerebellum, in association w...

It is not known whether, during the course of ageing, changes occur in the motor strategies used by the CNS for lifting objects of different weights. Here, we analysed the kinematics of object-lifting in two different healthy groups (young and elderly people) plus one well known deafferented patient (GL). The task was to reach and lift onto a shelf...

Introduction During last years the putative effects of cerebellar transcranial direct-current stimulation (tDCS) has attracted the attention of basic and clinical neuroscientist. Nevertheless, the impact of exogenous electric fields on the different components of the cerebellar network is not already elucidated. Objectives The aim of this study wa...

Human brain adaptation in weightlessness follows the necessity to reshape the dynamic integration of the neural information acquired in the new environment. This basic aspect was here studied by the electroencephalogram (EEG) dynamics where oscillatory modulations were measured during a visuo-attentional state preceding a visuo-motor docking task....

Brain dynamics is at the basis of top performance accomplishment in sports. The search for neural biomarkers of performance remains a challenge in movement science and sport psychology. The noninvasive nature of high-density electroencephalography (EEG) recording has made it a most promising avenue for providing quantitative feedback to practitione...

In order to characterize the neural signature of a motor imagery (MI) task, the present study investigates for the first time the oscillation characteristics including both of the time-frequency measurements, event related spectral perturbation and intertrial coherence (ITC) underlying the variations in the temporal measurements (event related pote...

Brain oscillations are, perhaps paradoxically, crucial for movement stability and high performance. Much of what is known about brain oscillations and their relation to movement, sensation and cognition has been established during the last three decades through an explosion of research ranging from in vitro (Draguhn et al., 1998; Fisahn a al., 1998...

Forty years ago, a consensual definition of the cerebral palsy concept was suggested, delineating it as a disorder of movement and posture secondary to non-progressive pathological processes that affect the immature brain. Because this concept is pragmatic and based on function, it has survived unaltered many changes in pathophysiolgical knowledge,...

This commentary is on the original article by Jongsma et al. on pages 277–284 of this issue.

Background: Children born preterm are at risk for developmental cerebral visual impairment. Several modalities of visual evoked potentials recording have been used to approach prognosis. The recent development of high-density EEG protocols allows evaluation of the oscillatory content of cortical activities evoked by specific stimulation. We aimed t...

Background: Angelman syndrome is a genetic neurodevelopmental disorder recognised to show characteristic (non-epileptic) high-amplitude slow rhythmic electroencephalographic patterns. These hypersynchronous neuronal activities have been studied to approach the pathophysiology of the condition. Aim: to analyse these patterns with enhanced recording...

Careful study of the phenotype can have implications at several levels, namely clinical diagnosis, pathophysiological reasoning, management planning, and outcome measurement. Behavioural phenotypes involve cognition, communication, social skills, and motor control. They can be documented in a host of neurodevelopmental conditions and approached wit...

Efforts to document early changes in the developing brain have resulted in the construction of increasingly accurate structural images based on magnetic resonance imaging (MRI) in newborn infants. Tractography diagrams obtained through diffusion tensor imaging have focused on white matter microstructure, with particular emphasis on neuronal connect...

The highly stereotyped, crystal-like architecture of the cerebellum has long served as a basis for hypotheses with regard to the function(s) that it subserves. Historically, most clinical observations and experimental work have focused on the involvement of the cerebellum in motor control, with particular emphasis on coordination and learning. Two...

Background Regulation of synaptic connectivity, including long-term depression (LTD), allows proper tuning of cellular signalling processes within brain circuitry. In the cerebellum, a key centre for motor coordination, a positive feedback loop that includes mitogen-activated protein kinases (MAPKs) is required for proper temporal control of LTD at...

Angelman syndrome (AS) is a genetic neurodevelopmental disorder in which cerebellar functioning impairment has been documented despite the absence of gross structural abnormalities. Characteristically, a spontaneous 160 Hz oscillation emerges in the Purkinje cells network of the Ube3a (m-/p+) Angelman mouse model. This abnormal oscillation is induc...

Powered exoskeletons can empower paraplegics to stand and walk. Actively controlled hip ab/adduction (HAA) is needed for weight shift and for lateral foot placement to support dynamic balance control and to counteract disturbances in the frontal plane. Here, we describe the design, control, and preliminary evaluation of a novel exoskeleton, MINDWAL...

During human walking, there exists a functional neural coupling between arms and legs, and between cervical and lumbosacral pattern generators. Here, we present a novel approach for associating the electromyographic (EMG) activity from upper limb muscles with leg kinematics. Our methodology takes advantage of the high involvement of shoulder muscle...