Biology subjects

Grouiller, F.

Publications and source records attributed to Grouiller, F..

3 recordsLinked to original sources

bioRxiv2023

Self-regulation of attention in children in a virtual classroom environment: a feasibility study

Attention is a crucial cognitive function that enables us to selectively focus on relevant information from the surrounding world to achieve our goals. When this sustained ability to direct attention is impaired, individuals face significant challenges in everyday life. This is the case for children with Attention Deficit Hyperactivity Disorder (ADHD), a complex neurodevelopmental disorder characterized by impulsive and inattentive behavior. While psychostimulant medications are currently the most effective treatment for ADHD, they often come with unwanted side effects, and sustaining the benefits can be difficult for many children. Therefore, it is imperative to explore non-pharmacological treatments that offer longer-lasting outcomes. Here, we proposed a groundbreaking protocol that combines electroencephalography-based neurofeedback (EEG-NFB) with virtual reality (VR) as an innovative approach to treating attention deficits. By integrating a virtual classroom environment, we aimed to enhance the transferability of attentional control skills while simultaneously increasing motivation and interest among children. The present study demonstrated the feasibility of this approach through an initial assessment involving a small group of healthy children, showcasing its potential for future evaluation in children diagnosed with ADHD. Encouragingly, the preliminary findings indicated high engagement rates and positive feedback from the children participating in the study. Additionally, the pre-and post-protocol assessments using EEG and fMRI recordings appeared to converge towards an improvement in attentional function. Although further validation is required to establish the efficacy of the proposed protocol, it represents a significant advancement in the field of neurofeedback therapy for ADHD. The integration of EEG-NFB and VR presents a novel avenue for enhancing attentional control and addressing behavioral challenges in children with ADHD.

neuroscience↗

bioRxiv2020

EEG and fMRI connectomes are reliably related: a simultaneous EEG-fMRI study from 1.5T to 7T

Both electroencephalography (EEG) and functional Magnetic Resonance Imaging (fMRI) are non-invasive methods that show complementary aspects of human brain activity. Despite measuring different proxies of brain activity, both the measured blood-oxygenation (fMRI) and neurophysiological recordings (EEG) are indirectly coupled. The electrophysiological and BOLD signal can map the underlying functional connectivity structure at the whole brain scale at different timescales. Previous work demonstrated a moderate but significant correlation between resting-state functional connectivity of both modalities, however there is a wide range of technical setups to measure simultaneous EEG-fMRI and the reliability of those measures between different setups remains unknown. This is true notably with respect to different magnetic field strengths (low and high field) and different spatial sampling of EEG (medium to high-density electrode coverage). Here, we investigated the reproducibility of the bimodal EEG-fMRI functional connectome in the most comprehensive resting-state simultaneous EEG-fMRI dataset compiled to date including a total of 72 subjects from four different imaging centers. Data was acquired from 1.5T, 3T and 7T scanners with simultaneously recorded EEG using 64 or 256 electrodes. We demonstrate that the whole-brain monomodal connectivity reproducibly correlates across different datasets and that a moderate crossmodal correlation between EEG and fMRI connectivity of r{approx}0.3 can be reproducibly extracted in low- and high-field scanners. The crossmodal correlation was strongest in the EEG-{beta} frequency band but exists across all frequency bands. Both homotopic and within intrinsic connectivity network (ICN) connections contributed the most to the crossmodal relationship. This study confirms, using a considerably diverse range of recording setups, that simultaneous EEG-fMRI offers a consistent estimate of multimodal functional connectomes in healthy subjects that are dominantly linked through a functional core of ICNs across spanning across the different timescales measured by EEG and fMRI. This opens new avenues for estimating the dynamics of brain function and provides a better understanding of interactions between EEG and fMRI measures. This observed level of reproducibility also defines a baseline for the study of alterations of this coupling in pathological conditions and their role as potential clinical markers.

neuroscience↗

bioRxiv2020

Whole-Brain High-Resolution Metabolite Mapping with 3D Compressed-Sensing-SENSE-LowRank 1H FID-MRSI

There is a growing interest in the neuroscience community to map the distribution of brain metabolites in vivo. Magnetic resonance spectroscopic imaging (MRSI) is often limited by either a poor spatial resolution and/or a long acquisition time which severely limits its applications for clinical or research purposes. Building on a recently developed technique of acquisition-reconstruction for 2D MRSI, we combined fast Cartesian 1H-FID-MRSI acquisition sequence, compressed-sensing acceleration, and low-rank total-generalized-variation constrained reconstruction to produce 3D high-resolution whole-brain MRSI with a significant acquisition time reduction. We first evaluated the acceleration performance using retrospective undersampling of a fully-sampled dataset. Second, a 20 min accelerated MRSI acquisition was performed on the brain of three healthy volunteers resulting in metabolite maps with 5 mm isotropic resolution. The metabolite maps exhibited the detailed neurochemical composition of all brain regions and revealed parts of the underlying brain anatomy. The latter assessment used previous reported knowledge and a brain atlas-based analysis to show consistency of the concentration contrasts and ratio across all brain regions. These results acquired on a clinical 3 Tesla MRI successful combinae of the 3D 1H-FID-MRSI with a constrained reconstruction to produce detailed mapping of metabolite concentrations at high-resolution over the whole brain, with an acquisition time suitable for clinical or research settings.

neuroscience↗