Movement imagery-related lateralization of event-related (de)synchronization (ERD/ERS): Motor-imagery duration effects

Objective: To investigate movement imagery-related lateralization of event-related (de)synchronization (ERD/ERS) during two motor-imagery tasks with varying movement duration (brief versus continuous). Methods: Twelve subjects performed or kinesthetically imagined the indicated movement (left or right hand movement) for 1 s (brief) or 5 s (continuous) while electroencephalograms (EEGs) were recorded using 16 electrodes covering the sensorimotor cortex of the brain according to the modified 10-20 system. Results: Significant hemispheric differences were found between contralateral and ipsilateral area in mu ERD, mu ERS and beta ERD during both brief and continuous conditions, showing contralateral dominance of mu and beta ERD and ipsilateral dominance of mu ERS. Beta ERS showed a significant ipsilateral dominance only in the brief condition. Movement imagery duration influenced the lateralization of mu ERD, beta ERD, and beta ERS, but not mu ERS. Conclusions: The results of this study will aid in clarifying movement-related lateralization in association with imagery tasks under varying movement duration. Significance: For designing an EEG-based brain-computer interface (BCI) for people with severe neuromuscular impairments, movement imagery-related lateralization can play a key role in utilizing motor-imagery tasks as a control or communication strategy. (c) 2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.