Desynchronization of the mu oscillatory activity during motor imagery: A preliminary EEG-fMRI study

The purpose of this study is to identify the correspondence between distinct brain oscillatory activity acquired from electroencephalography (EEG) and blood oxygenation level dependent signals obtained from functional magnetic resonance imaging (fMRI). In this preliminary study, the changes in the mu rhythmic power (8-13Hz) during motor imagery tasks in the EEG data simultaneously acquired with fMRI data were examined. The average mu powers during the left-hand (LH)/right-hand (RH) motor imagery tasks were separately estimated after removing dominant artifacts, such as gradient artifact, ballistocardiogram artifact, and helium-pump artifact. As a result, the relatively lower mu power of the contralateral motor area during LH/RH motor imagery tasks was observed compared to ipsilateral side. This observation indicates a functional signature for motor imagery tasks.