Wavelet analysis as a tool for investigating movement-related cortical oscillations in EEG-fMRI coregistration

Silvia Francesca Storti, Emanuela Formaggio, Alberto Beltramello, Antonio Fiaschi, Paolo Manganotti

Research output: Contribution to journalArticle

Abstract

Electroencephalography combined with functional magnetic resonance imaging (EEG-fMRI) identifies blood oxygenation level dependent (BOLD) signal changes associated with physiological and pathological EEG events. In this study we used EEG-fMRI to determine the possible correlation between topographical movement-related EEG changes in brain oscillatory activity recorded from EEG electrodes over the scalp and fMRI cortical responses in motor areas during finger movement. Thirty-two channels of EEG were recorded in 12 subjects during eyes-closed condition inside a three T magnetic resonance (MR) scanner using an MR-compatible EEG recording system. Off-line MRI artifact subtraction software was applied to obtain continuous EEG data during fMRI acquisition. For EEG data analysis we used a time-frequency approach to measure time by varying the energy in a signal at a given frequency band by the convolution of the EEG signal with a wavelet family in the alpha and beta bands. The correlation between the BOLD signal associated with the EEG regressor provides that sensory motor region is a source of the EEG. We conclude that combined EEG-fMRI can be used to investigate movement-related oscillations of the human brain inside an MRI scanner and wavelet analysis adds further details on the EEG changes. The movement-related changes in the EEG signals are useful to identify the brain activation sources responsible for BOLD-signal changes.

Original languageEnglish
Pages (from-to)46-57
Number of pages12
JournalBrain Topography
Volume23
Issue number1
DOIs
Publication statusPublished - Mar 2010

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Keywords

  • BOLD
  • EEG
  • Maps
  • Wavelet analysis
  • Wavelet energy

ASJC Scopus subject areas

  • Anatomy
  • Clinical Neurology
  • Radiology Nuclear Medicine and imaging
  • Neurology
  • Radiological and Ultrasound Technology

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