Learning-induced modulation of scale-free properties of brain activity measured with MEG

Nicolas Zilber (1) , Philippe Ciuciu (2) , Patrice Abry (3) , Virginie van Wassenhove (4)

1 LNAO - Laboratoire de Neuroimagerie Assistée par Ordinateur
2 PARIETAL - Modelling brain structure, function and variability based on high-field MRI data
3 Phys-ENS - Laboratoire de Physique de l'ENS Lyon
4 UNICOG-U992 - Neuroimagerie cognitive - Psychologie cognitive expérimentale

Previous studies have suggested that infraslow brain activity could play an important role in cognition. Its scale-free properties (coarsely described by its 1/f power spectrum) are indeed modulated between contrasted conscious states (sleep vs. awake). However, finer modulations remain to be investigated. Here, we make use of a robust multifractal analysis to investigate the group-level impact of perceptual learning (visual (V), or audiovisual (AV), N=12 subjects in each group) on the source reconstructed scale-free activity recorded with magnetoencephalography (MEG) during rest and task. We first observed a significant decrease of self-similarity in evoked activity during the task after both trainings. More interestingly, only the most efficient training (AV) induced a decrease of self-similarity in spontaneous activity at rest whereas only V training induced an increase of multifractality in evoked activity.

Domaines: Traitement du signal et de l'image [eess.SP]; Traitement du signal et de l'image [eess.SP]; Sciences cognitives

Nicolas Zilber, Philippe Ciuciu, Patrice Abry, Virginie van Wassenhove. Learning-induced modulation of scale-free properties of brain activity measured with MEG. 10th IEEE International Symposium on Biomedical Imaging, IEEE, Apr 2013, San Francisco, United States. pp.998-1001, ⟨10.1109/ISBI.2013.6556645⟩. ⟨hal-00859389⟩