Hand mental rotation reaction time reflects motor imagery strategy and predicts changes in finger dexterity after motor imagery
Yuki Fukumoto, Keisuke Fujii, Marina Todo, Toshiaki SuzukiBackground
Motor imagery can improve motor performance, but its effects vary among individuals. Hand mental rotation may reflect individual characteristics related to motor imagery processing, including imagery strategies. This study examined whether the reaction time in a hand mental rotation task could explain interindividual differences in motor imagery-induced changes in finger dexterity and spinal motor neuron excitability.
Methods
Participants were classified into ‘good’ and ‘poor’ groups according to the reaction times for right- and left-hand mental rotation judgments. Finger dexterity was assessed using the Purdue Pegboard task, and spinal motor neuron excitability during motor imagery was evaluated using F-waves.
Results
Grouping based on hand mental rotation reaction time showed no interaction effect on the F/M amplitude ratio. In contrast, grouping based on left-hand mental rotation reaction time revealed greater improvement in finger dexterity in the poor group. Left-hand mental rotation reaction time showed a weak association with backward digit span performance but not with other measures of working memory.
Conclusion
The hand mental rotation reaction time may reflect differences in motor imagery strategy rather than motor imagery ability and may explain interindividual differences in motor imagery–related improvements in finger dexterity.