Temporal Dynamics of Motor Imagery Comparing Accuracy for Human and Robot Actions: Stimuli and Data

This study explored motor imagery of robotic versus human actions using a temporal judgment task.

Participants observed videos of actions performed by either a human or a NAO robot and then performed motor imagery of the observed action until a stop signal interrupted them. Subsequently, they completed a two-alternative forced choice task to identify the frame corresponding to their imagery stop point. The choice was between the correct frame and either a preceding ('Before') or succeeding ('After') frame.

The availability of the participants’ motor system was also manipulated by comparing performance when their dominant arm was free versus restrained.

Results revealed higher accuracy for robotic actions compared to human actions. Furthermore, a systematic bias towards 'After' incorrect frames emerged, suggesting an accelerated nature of motor imagery. Crucially, the enhanced accuracy for robotic actions was primarily evident for 'After' incorrect frames, indicating that the predictability of robot movements may facilitate temporal precision, especially in the later stages of motor imagery. Arm restraint did not significantly modulate performance.

These findings challenge simplistic embodied simulation accounts and underscore the role of action predictability and cognitive strategies in shaping the temporal dynamics of motor imagery, offering novel insights into human-robot interaction and potential implications for motor rehabilitation strategies.