Gymnasts' ability for general motor imagery evaluated by bioelectric sensorimotor rhythms

Introduction: Previous psychological studies using questionnaires have consistently reported that athletes have superior motor imagery ability, both for sports-specific movements and general movements. However, regarding general motor imagery, no physiological studies have demonstrated differences in neural activity between athletes and non-athletes. Gymnasts may be a suitable population for investigating this issue because they are likely to have particularly superior motor imagery ability due to their frequent usage of motor imagery as part of daily practice. Purpose: The purpose of the present study was to examine differences in bioelectric sensorimotor rhythms during kinesthetic motor imagery of general movements between gymnasts and non-gymnasts. Methods: Healthy young participants (16 gymnasts and 16 non-gymnasts) performed repeated motor execution and motor imagery of general movements (wrist dorsiflexion and shoulder abduction of the dominant hand). Scalp electroencephalogram (EEG) was recorded over the contralateral sensorimotor cortex. During motor execution and motor imagery, sensorimotor EEG power is known to decrease in the α- (8-15 Hz) and β-bands (16-35 Hz), referred to as event-related desynchronization (ERD). We calculated the maximal peak of ERD both in the α- (αERDmax) and β-bands (βERDmax) as a measure of changes in corticospinal excitability. Results: ERD magnitude during motor imagery was significantly greater in gymnasts, who subjectively evaluated their motor imagery as being more vivid. In particular, αERDmax was greater in gymnasts compared with non-gymnasts for both motor imagery tasks, whereas βERDmax was greater in gymnasts only for shoulder abduction imagery. Conclusion: We observed gymnasts9 signature of flexibly modulating sensorimotor rhythm with no movement, which may be the basis of their superior general motor imagery ability.