Neuro-narrative games represent an emerging integration of brain-computer interface (BCI) and virtual reality (VR) technologies, leveraging imagery perspective and motor imagery (MI) task sequence as two critical design factors. However, the individual and combined influences of these factors on system usability remain underexplored, especially regarding the interaction between first- and third-person perspectives and the structuring of MI task sequences. This paper presents a unified evaluation framework that combines objective electroencephalogram (EEG)-based usability metrics with subjective user feedback to provide a comprehensive assessment in a custom-designed, user-centered BCI-VR narrative game system. Employing a within-subject experimental design, we systematically examine the main and interaction effects of perspective and sequence structure, revealing that immersive VR can mitigate perspective-induced usability gaps and that fixed MI sequences reduce cognitive workload and enhance user performance. Conversely, mixed task sequences boost user motivation but lead to increased mental workload. These findings contribute actionable design guidelines for expanding accessible, engaging, and user-centered BCI-VR game experiences to a broader range of users, ultimately supporting the development of more effective neuro-narrative systems. Importantly, our approach bridges objective neural data with subjective user experience, paving the way for holistic usability evaluation in future BCI-VR applications.

Zoning out, a form of cognitive disengagement, seriously challenges the effectiveness of virtual reality (VR) based upper limb rehabilitation. As therapy often involves repetitive tasks requiring sustained attention, undetected lapses in focus can reduce motor learning, engagement, and overall recovery outcomes. This research addresses this gap by proposing ZonAware, a novel strategy integrating real-time zoning out detection with adaptive intervention to enhance user engagement during VR rehabilitation. ZonAware identifies zoning out using five eye-tracking metrics: blink frequency, blink duration, pupil size, eye openness, and gaze duration. These signals are analysed through lightweight statistical models (Z-Score, Boxplot, and Modified Z-Score), with a hard voting mechanism producing binary classifications in real-time. Upon detection, a pattern changing intervention subtly modulates task difficulty by temporarily increasing, then decreasing it, to regain user focus without breaking immersion. Three user studies involving 70 healthy participants and 22 patients demonstrated the strategy's effectiveness. ZonAware achieved 98.24% detection accuracy with low latency (82-150 ms), reducing zoning out frequency by 53.57% and shortening disengagement duration from 18.1 to 4.8 seconds. The approach also improved user engagement, performance, and emotional motivation. ZonAware delivers one of the first real-time zoning out solutions for VR rehabilitation, offering an interpretable, theory-driven approach that enhances attention, engagement, and adaptability in human-computer interaction.

Integrating biofeedback technology, such as real-time eye-tracking, has revolutionized the landscape of virtual reality (VR) rehabilitation games, offering new opportunities for personalized therapy. Motivated to increase patient focus during rehabilitation, the Focus-Driven Augmented Feedback (FDAF) system was developed to enhance focus and maintain engagement during upper limb VR rehabilitation. This novel approach dynamically adjusts augmented visual feedback based on a patient's gaze, creating a personalised rehabilitation experience tailored to individual needs. This research aims to develop and comprehensively evaluate the FDAF system to enhance patient focus and maintain engagement in VR rehabilitation environments. The methodology involved three experimental studies, which tested varying levels of augmented feedback with 71 healthy participants and 17 patients requiring upper limb rehabilitation. The results demonstrated that a 30% augmented level was optimal for healthy participants, while a 20% was most effective for patients, ensuring sustained engagement without inducing discomfort. The research's findings highlight the potential of eye-tracking technology to dynamically customise feedback in VR rehabilitation, leading to more effective therapy and improved patient outcomes. This research contributes significant advancements in developing personalised VR rehabilitation techniques, offering valuable insights for future therapeutic applications.

The use of Virtual Reality (VR) technology, especially in medical rehabilitation, has expanded to include tactile cues along with visual stimuli. For patients with upper limb hemiplegia, tangible handles with haptic stimuli could improve their ability to perform daily activities. Traditional VR controllers are unsuitable for patient rehabilitation in VR, necessitating the design of specialized tangible handles with integrated tracking devices. Besides, matching tactile stimulation with corresponding virtual visuals could strengthen users' embodiment (i.e., owning and controlling virtual bodies) in VR, which is crucial for patients' training with virtual hands. Haptic stimuli have been shown to amplify the embodiment in VR, whereas the effect of partial tactile stimulation from tangible handles on embodiment remains to be clarified. This research, including three experiments, aims to investigate how partial tactile feedback of tangible handles impacts users' embodiment, and we proposed a design concept called TouchMark for partial tactile stimuli that could help users quickly connect the physical and virtual worlds. To evaluate users' tactile and comfort perceptions when grasping tangible handles in a non-VR setting, various handles with three partial tactile factors were manipulated in Study 1. In Study 2, we explored the effects of partial feedback using three forms of TouchMark on the embodiment of healthy users in VR, with various tangible handles, while Study 3 focused on similar investigations with patients. These handles were utilized to complete virtual food preparation tasks. The tactile and comfort perceptions of tangible handles and users' embodiment were evaluated in this research using questionnaires and interviews. The results indicate that TouchMark with haptic line and ring forms over no stimulation would significantly enhance users' embodiment, especially for patients. The low-cost and innovative TouchMark approach may assist users, particularly those with limited VR experience, in achieving the embodiment and enhancing their virtual interactive experience.

As players demand better-quality horror games, a study is conducted to find the more practical design choices to induce fear and tension in first-person PC horror games. This research investigates designs on enemy appearances and movement artificial intelligence logic and builds corresponding demos for experiments. The data is collected by questionnaires and experiments that record participants’ heart rates when playing horror games. The results show that using enemy designs with uncanny valley effect appearance and outflanking behaviour movement AI effectively induces fear and tension in first-person PC horror games. This study makes contribution to the design guidelines for game designers and developers in developing better-quality horror games.