DocumentCode :
2573578
Title :
Modulation of scale-free properties of brain activity in MEG
Author :
Zilber, Nicolas ; Ciuciu, Philippe ; Abry, Patrice ; Van Wassenhove, Virginie
Author_Institution :
IBM NeuroSpin center, CEA, Gif-sur-Yvette, France
fYear :
2012
fDate :
2-5 May 2012
Firstpage :
1531
Lastpage :
1534
Abstract :
The analysis of scale-free (i.e., 1/f power spectrum) brain activity has emerged in the last decade since it has been shown that low frequency fluctuations interact with oscillatory activity in electrophysiology, noticeably when exogenous factors (stimuli, task) are delivered to the human brain. However, there are some major difficulties in measuring scale-free activity in neuroimaging data: they are noisy, possibly nonstationary ... Here, we make use of multifractal analysis to better understand the biological meaning of scale-free activity recorded with Magnetoencephalography (MEG) data. On a cohort of 20 subjects, we demonstrate the presence of self-similarity on all sensors during rest and visually evoked activity. Also, we report significant multifractality on the norm of gradiometers. Finally, on the latter signals we show how self-similarity and multifractality are modulated between ongoing and evoked activity.
Keywords :
magnetoencephalography; medical signal processing; neurophysiology; visual evoked potentials; MEG; brain activity; electrophysiology; gradiometer; low frequency fluctuation; magnetoencephalography; multifractal analysis; multifractality; neuroimaging data; oscillatory activity; rest activity; scale-free activity; self-similarity; signal modulation; visually evoked activity; Brain; Electroencephalography; Fractals; Modulation; Sensors; Time series analysis; Wavelet analysis; MEG; multifractal analysis; scale-free activity; scaling;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Biomedical Imaging (ISBI), 2012 9th IEEE International Symposium on
Conference_Location :
Barcelona
ISSN :
1945-7928
Print_ISBN :
978-1-4577-1857-1
Type :
conf
DOI :
10.1109/ISBI.2012.6235864
Filename :
6235864
Link To Document :
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