ERF and scale-free analyses of source-reconstructed MEG brain signals during a multisensory learning paradigm
type: Dataset
description: The analysis of Human brain activity in magnetoencephalography (MEG) can be generally conducted in two ways: either by focusing on the average response evoked by a stimulus repeated over time, more commonly known as an ``event-related field'' (ERF), or by decomposing the signal into functionally relevant oscillatory or frequency bands (such as alpha, beta or gamma). However, the major part of brain activity is arrhythmic and these approaches fail in describing its complexity, particularly in resting-state. As an alternative, the analysis of the 1/f-type power spectrum observed in the very low frequencies, a hallmark of scale-free dynamics, can overcome these issues. Yet it remains unclear whether this scale-free property is functionally relevant and whether its fluctuations matter for behavior. To address this question, our first concern was to establish a visual learning paradigm that would entail functional plasticity during an MEG session. In order to optimize the training effects, we developed new audiovisual (AV) stimuli (an acoustic texture paired with a colored visual motion) that induced multisensory integration and indeed improved learning compared to visual training solely (V) or accompanied with acoustic noise (AVn). This led us to investigate the neural correlates of these three types of training using first a classical method such as the ERF analysis. After source reconstruction on each individual cortical surface using MNE-dSPM, the network involved in the task was identified at the group-level. The selective plasticity observed in the human motion area (hMT+) correlated across all individuals with the behavioral improvement and was supported by a larger network in AV comprising multisensory areas. On the basis of these findings, we further explored the links between the behavior and scale-free properties of these same source-reconstructed MEG signals. Although most studies restricted their analysis to the global measure of self-similarity (i.e. long-r…
identifier: NNT: 2014PA112040
issued: 2026-05-05T12:43:36.434510
language: en
modified: 2026-05-05T12:43:36.434515
contact point: Organization
  fn: CCSD
keyword: activite-basse-frequence
keyword: apprentissage
keyword: audiovisual
keyword: audiovisuel
keyword: colored-motion
keyword: infoeu-reposemanticsdoctoralthesis
keyword: infraslow-activity
keyword: invariance-dechelles
keyword: learning
keyword: loi-de-puissance
keyword: meg
keyword: mouvement-colore
keyword: multifractalite
keyword: multifractality
keyword: multisensoriel
keyword: multisensory
keyword: physcondcm-genphysics-physicscondensed-matter-cond-matother-cond-matother
keyword: plasticite
keyword: plasticity
keyword: power-law
keyword: repos
keyword: resting-state
keyword: scale-invariance
keyword: theses
keyword: wlbmf
landing page: https://theses.hal.science/tel-00984990

ERF and scale-free analyses of source-reconstructed MEG brain signals during a multisensory learning paradigm
type: Distribution
format: HTML
issued: 2026-05-05T12:43:36.436835
modified: 2026-05-05T12:43:36.405288
access URL: https://theses.hal.science/tel-00984990

test_moissonnage_selune
type: Agent