## 4 Discussion
### Usability and User Experience  
The TMT-VR received high ratings for usability, user experience, and acceptability, reflecting the successful application of UCD principles in its development. UCD emphasizes creating systems that are not only functional but also tailored to meet the specific needs and preferences of users, thereby enhancing overall satisfaction and effectiveness. The positive evaluations observed across all participants, regardless of their gaming or technology experience, indicate that the TMT-VR is accessible and user-friendly. This is a significant achievement, as it suggests that the TMT-VR can be effectively used in diverse populations, including those who may not be familiar with VR technology [2]. Furthermore, those findings indicate that TMT-VR has the potential to increase accessibility in cognitive evaluations by adhering to the distinct requirements and preferences of diverse populations. This is crucial for groups that may otherwise face barriers in conventional cognitive assessment techniques, such as individuals with physical impairments and older adults. This broad applicability is crucial for neuropsychological assessments, which often need to cater to a wide range of users, including clinical populations and older adults who may have limited technological exposure [75]. Figure 7: Accuracy in TMT-VR Task B per interaction mode. Accuracy is displayed as a Z score of the distance from the center. \(p<0.01\)**. The development of the TMT-VR adhered closely to the ISO 9241-210:2019 standards for Ergonomics of Human-System Interaction, which provide comprehensive guidelines for designing interactive systems that are efficient, effective, and satisfying for users [58]. By aligning the design of the TMT-VR with these standards, the developers ensured that the tool not only met the technical requirements for usability but also addressed the ergonomic needs of users, reducing the likelihood of discomfort and cognitive overload during the assessment process. This alignment with ISO standards is critical in the context of VR, where user comfort and interaction quality are paramount to prevent issues like cognitive fatigue and physical discomfort, which can negatively impact the user experience and the validity of the assessment outcomes [76]. Incorporating specific features to mitigate common VR issues, such as the Midas touch effect and cybersickness, further contributed to the positive user experience reported in this study. The Midas touch effect, which occurs when a system interprets unintended user actions as intentional, can be particularly problematic in VR environments where precise control is necessary [61]. To address this, the TMT-VR implemented a two-second confirmation delay for target selection, allowing users to correct potential errors before finalizing their actions. This feature is consistent with best practices in VR interface design, which recommend implementing safeguards against inadvertent actions to enhance user control and reduce frustration [60]. Cybersickness, another common issue in VR, can manifest as symptoms such as dizziness, nausea, and disorientation, often resulting from discrepancies between visual and vestibular inputs [77]. The TMT-VR's design includes measures to minimize these effects, such as optimizing the frame rate and implementing smooth, consistent motion within the virtual environment. These strategies are in line with the recommendations for reducing VR-induced symptoms, which emphasize the importance of maintaining a high level of visual fidelity and ensuring that user movements are accurately reflected in the virtual space [78]. The successful mitigation of cybersickness in the TMT-VR is particularly important for its application in clinical settings, where users may already be vulnerable to discomfort or disorientation [2]. Furthermore, the TMT-VR's design carefully considered the user experience by incorporating elements that enhance immersion and reduce potential barriers to effective interaction.