Bilateral vs unilateral motor imagery training: effects on motor execution performance and ERD

Abstract

Bilateral movement has been reported to enhance actual motor performance more than unilateral movement and increase motor cortex activation more than unilateral movement. We hypothesized that bilateral motor imagery would result in greater improvements in event-related desynchronization (ERD) amplitude and ball rotation performance than unilateral motor imagery. Forty healthy young adults participated in this study. The mental practice session was performed in the unilateral hand condition (right and left hands) and bilateral hand condition for four blocks. ERD in mental practice was calculated using electroencephalography (EEG). The ball rotations were compared between the pre-and post-tests of mental practice. The results showed a greater improvement in actual motor performance with unilateral motor imagery than with bilateral motor imagery. ERD analysis showed no significant differences in multiple comparisons. These results did not support this hypothesis. Nonetheless, the present study showed that unilateral movements resulted in greater performance gains than bilateral movements, suggesting that bilateral motor imagery may have additional control processes similar to actual movements.