## 4 Discussion
### Multiple Health Goals: Integrating Physical and Cognitive Wellness
Additionally, [PERSON] et al. [21] assessed the cognitive abilities of older adults through gamified cognitive training in VR, finding that although the correlation between the gamified test and traditional test results was weak, participants' engagement and learning in the virtual environment were still significant, further demonstrating the potential of VR to intervene in cognitive functions. Therefore, future research should focus on systematic design and evaluation to enhance the effectiveness and relevance of VR interventions for cognitive function. In addition, Self-Determination Theory (SDT) provides an important perspective for understanding how these virtual reality (VR) health games can effectively enhance engagement and motivation among older adults [29]. According to SDT, satisfying three basic psychological needs--autonomy, competence, and relatedness--can enhance intrinsic motivation and long-term willingness to participate [30]. For example, in the multitasking VR game designed by [PERSON] et al. [26], participants were able to independently choose the difficulty of the task (satisfying autonomy) and received timely feedback after completing complex tasks, which enhanced their sense of accomplishment (satisfying competence). However, existing research has not thoroughly explored the specific impact of difficulty selection on participants' long-term motivation, limiting our understanding of how autonomy fosters sustained engagement. Similarly, the socially collaborative VR game designed by [PERSON] et al. [12] enhanced older adults' sense of social connectedness through teamwork (satisfying relatedness), thereby significantly increasing their willingness to participate and motivation to exercise. Nonetheless, a systematic assessment of how teamwork influences motivation across different social contexts remains unexamined, potentially affecting the design and implementation of such games. Furthermore, [PERSON] et al. [23] demonstrated that highly interactive and collaborative VR games can strengthen older adults' social support networks and enhance their sense of belonging. These cases show that meeting the psychological needs outlined by SDT not only increases older adults' acceptance of VR interventions but also promotes their long-term engagement and health goals. However, future research should place greater emphasis on how to meet these needs in various social and cultural contexts to further improve the effectiveness and applicability of VR interventions. In terms of mental health improvement, several studies have shown that VR can significantly enhance the emotional state and mental well-being of older adults. [PERSON] et al. [19] conducted a study on the effects of VR on the mood of older adults and found that engaging in virtual activities led to significant mood improvements, especially among older adults who had fewer interactions with others or felt lonely. This indicates that VR provides an immersive entertainment and interactive experience that helps older adults reduce negative emotions such as anxiety and depression. However, while these studies reveal VR's potential in improving mood, there is still a lack of assessment regarding its long-term effects, particularly considering different social backgrounds and individual differences. Future research should comprehensively explore the long-term impacts of VR on the mental health of older adults and the underlying mechanisms involved. Additionally, [PERSON] et al. [18] further investigated the immersion and psychological burden experienced by older adults when using VR, finding that older adults reported comparable levels of immersion to younger adults while experiencing lower psychological burden and discomfort. This suggests that VR can provide a safe and comfortable means for psychological adjustment.