Enhancing Usability with Virtual Imagery: Insights into Feedback Mechanism from a BCI-VR Integrated System

The integration of brain-computer interface (BCI) and virtual reality (VR) technologies has fostered innovative applications in medical rehabilitation, education, and entertainment. One prominent application is the motor imagery (MI)-based BCI-VR system, which allows users to control the system through imagined movements without physical motion. Despite these advancements, the usability of a such system remains a significant challenge, primarily due to limited user feedback mechanisms. This study addresses this gap by designing and evaluating four haptic feedback modes to enhance user interaction in MI-based BCI-VR systems. Specifically, the research introduces a novel approach by integrating pseudo-haptic feedback - the illusion of touch created through visual and auditory stimuli - alongside traditional physical feedback. Using a within-subjects experimental design, the study assesses the impact of different combinations of physical and pseudo-haptic feedback on haptic perception, user workload, and satisfaction. The results indicate that the combination of both pseudo-haptic and physical feedback significantly enhances user satisfaction (M=2.25, SD=0.46) and perceived vibration level (M=9.25, SD=1.03), although it also increases the workload. These findings suggest that carefully balanced haptic feedback can improve the usability and overall user experience of MI-based BCI-VR systems, providing practical insights for system optimization.