23. Adjusting Brain Activity with Body Ownership Transfer

Feedback design is an important issue in motor imagery brain–computer interface (BCI) systems. However, extant research has not reported on the manner in which feedback presentation optimizes coadaptation between a human brain and motor imagery BCI systems. This study assesses the effect of realistic visual feedback on user BCI-performance and motor imagery skills. A previous study developed a teleoperation system for a pair of humanlike robotic hands and showed that the BCI control of the hands in conjunction with first-person perspective visual feedback of movements arouses a sense of embodiment in the operators. In the first stage of this study, the results indicated that the intensity of the ownership illusion was associated with feedback presentation and subject performance during BCI motion control. The second stage investigated the effect of positive and negative feedback bias on BCI-performance of subjects and motor imagery skills. The subject-specific classifier that was set up at the beginning of the experiment did not detect any significant changes in the online performance of subjects, and the evaluation of brain activity patterns revealed that the subject’s self-regulation of motor imagery features improved due to a positive feedback bias and the potential occurrence of ownership illusion. The findings suggest that the manipulation of feedback can generally play an important role with respect to training protocols for BCIs in the optimization of the subject’s motor imagery skills.