Short-Interval Priming Effects: An EEG Study of Action Observation on Motor Imagery

How to effectively set and adjust training tasks is the main challenge of task-oriented rehabilitation. Recent studies have shown that motor priming effects could be used as an important reference for task setting. However, the use of assessment scales to quantify priming effects lacks timeliness. This study focused on evaluating the motor priming effects on a smaller timescale using electroencephalogram (EEG). Six healthy adults were recruited to perform motor imagery (MI) of elbow flexion extension primed by the same action observation (AO). The control task replaced AO with arrows indicating different elbows. The motor priming effects were evaluated by the event-related desynchronization (ERD) of
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band (8–13 Hz) power and single-trial classification of left or right elbow MI. Both ERD intensity and classification accuracy of MI primed by AO were more significant than MI instructed by arrows. The results demonstrated that short-interval motor priming effects could be evaluated at the neural level and could be used as feasible neurofeedback to guide task-oriented rehabilitation.