## 4 Discussion
### Comparison of Interaction Modes  
The comparison of interaction modes demonstrated that both eye tracking and headset interactions offer distinct advantages over traditional controller-based interaction. Eye tracking proved particularly effective for tasks requiring depth perception, where precise visual focus on distant targets is essential [79]. The headset, however, provided a balance of speed and precision, making it an effective mode for tasks that require rapid and accurate responses [80]. These findings suggest that the choice of interaction mode can be tailored to the specific needs of the user and the nature of the task, with both eye tracking and headset interactions providing naturalistic and intuitive options for VR assessments [2]. This adaptability highlights the potential of these interaction modes to enhance the accessibility and effectiveness of VR-based cognitive assessments.  
The finding that both eye tracking and head movement modes outperformed controller-based interaction in terms of accuracy and task completion time presents important implications for the future of VR interaction design. While controllers are currently the dominant mode of interaction in most VR applications, this study suggests that they may not always be the most efficient or accurate method for specific tasks, particularly those requiring precise targeting and rapid responses. One possible explanation for the superior performance of eye tracking and head movement modes lies in their alignment with natural human behaviors. Eye tracking and head movement are intrinsic to how we interact with the real world, where we use our eyes and heads to focus on and select objects. This natural alignment likely reduces cognitive load, allowing users to interact with the virtual environment more intuitively and efficiently than with controllers, which require hand-eye coordination and manual dexterity. Additionally, these modes may offer ergonomic benefits by reducing physical demand compared to controllers, which could help maintain accuracy and speed over longer periods, particularly in tasks that require sustained precision.  
These findings have significant implications for the design and development of future VR software. While controllers have been the focus due to their widespread use and adaptability, the potential of eye tracking and head movement to provide more efficient and user-friendly interactions deserves greater attention. As VR technology continues to evolve, developers might consider integrating or even prioritizing these alternative interaction modes, offering users more intuitive and less physically demanding ways to interact with virtual environments. Future research could explore the development of hybrid interaction systems that combine the strengths of all these modes, allowing users to choose the most appropriate method for their specific tasks. In conclusion, while controller-based interaction remains prevalent in VR applications, this study demonstrates that alternative modes such as eye tracking and head movement may offer significant benefits in terms of accuracy and task completion time, suggesting a potential shift in how we think about VR interaction design.