Distinct neural representations of hand movement direction between motor imagery and execution in the presupplementary motor area

Motor simulation theory proposes a functional equivalence between motor execution (ME) and its simulation, suggesting that motor imagery (MI) is the self-intentioned simulation of one’s actions. This study used functional magnetic resonance imaging (fMRI) with multivoxel pattern analysis to test whether the direction of hand movement is represented with a similar neural code between ME and MI. In our study, participants used their right hand to move an on-screen cursor in the left–right direction with a joystick or imagined the same movement without execution. The results indicated that the left–right direction as well as their modality (ME or MI) could be decoded significantly above the chance level in the presupplementary motor area (pre-SMA) and primary visual cortex (V1). Next, we used activation patterns of ME as inputs to the decoder to predict hand move directions in MI sessions and found a significantly higher-than-chance accuracy only in V1, not in pre-SMA. Moreover, the representational similarity analysis showed similar activation patterns for the same directions between ME and MI in V1 but not in pre-SMA. This study’s finding indicates distinct spatial activation patterns for movement directions between ME and MI in pre-SMA. •We tried to decode the left-right direction of hand movement (ME) and imagery (MI).•The direction could be decoded in pre-SMA and V1 during ME and MI, respectively.•The neural codes of direction between ME and MI were different in pre-SMA.