## 1 Introduction
Implicit and automatic forms of ER can be more efficient and effortless than explicit forms, but they are also less flexible and can run to completion without monitoring [26]. Explicit ER strategies, such as cognitive reappraisal, depend on neural circuits in the prefrontal cortex [27; 28], and these cortical areas have been implicated in both EFs and ERs in clinical [29] and healthy populations [30]. Cognitive training programs include a variety of exercises that challenge different cognitive abilities. For example, exercises that require focusing attention while ignoring distractions (i.e., inhibitory control), managing multiple stimuli simultaneously (divided attention and working memory), switching between tasks, and solving different dynamic problems (i.e., cognitive flexibility) [31]. However, these exercises are often criticized for having low ecological validity. That is, they do not always mimic real-life situations well and are sometimes described as unstimulated, repetitive, and even boring [32; 33; 34; 35]. Recently, new studies using technology, like virtual reality (VR) games, have shown that these immersive programs can have positive effects on training cognitive functions, including EFs. These VR-based cognitive training programs have shown promising results in both clinical and healthy populations, improving various cognitive skills, psychological well-being, and even mental health issues in both childhood and adolescence [5; 36; 37; 38; 39]. For instance, VR cognitive rehabilitation and stimulation has been shown to enhance paper- and/or computer-based cognitive training for adults and older adults with cognitive impairments and dementia [40]. The immersive and engaging nature of this technology could also make it an attractive educational tool within the school curriculum. By replicating realistic scenarios, VR-based cognitive training can help individuals train cognitive skills while managing emotions in triggering contexts [38; 40], for example, recognizing and managing negative emotions in a simulated stressful home- or school-based environment. In addition, VR-based cognitive programs can harness motivational factors, reduce dropout rates, and promote greater engagement [41]. This, in turn, may increase adolescents' motivation and participation, thereby increasing their likelihood of completing the program and reaping the benefits of the intervention. This is particularly important for school-based interventions, where maintaining ongoing participation can be a challenge [42]. This pilot study will implement VR-based cognitive training focused on improving the cognition and mental health of school-aged students at risk for developing EDs during early adolescence. As mentioned earlier, students at risk for ED face greater challenges in adapting to the school environment, which requires the proper development of these functions for both academic learning and socio-emotional adjustment [2; 3; 4]. Therefore, this study aims to evaluate the preliminary effects of VR-based gamified cognitive training on improving EFs, ER skills, internalizing symptoms, ruminative symptoms, and self-efficacy levels. The VR cognitive training will be compared to an active control condition (nature-based VR relaxation training). This intervention was chosen as the active control because relaxation techniques, such as deep breathing, are considered a traditional method for improving ER [43; 44; 45] and also have moderately positive effects on internalizing symptoms in adolescents [46]. Furthermore, we ensured that both groups received a similar immersive VR experience (i.e., in terms of number and duration of sessions, as well as the technological hardware). Specifically, we expected that the experimental group would show significantly greater improvements in EFs, ER, self-efficacy, and internalizing symptoms than the active control group. Although we also expected to observe improvements in ER, self-efficacy, and internalizing symptoms, but not in EFs, in the control group.