## 2 Material and Methods
### Statistical Analysis  
The statistical evaluations were performed using IBM SPSS Statistics V.27. The normality of data distributions was verified using the Shapiro-Wilk test, with a significance threshold established at \(p\leq 0.05\) for identifying statistically significant results. Initially, mean values and standard deviations were calculated for the ReT and the 2 HAND test outcomes. Subsequently, a detailed 4 \(\times\) 3 \(\times\) 5 mixed model ANOVA was conducted to explore the main effects and interactions among time (pre, post, follow-up), measurement (RT, MT, EHC, TPED, AET), and group (E8, E28, C8, C28). A 4 \(\times\) 3 \(\times\) 5 mixed model ANOVA was specifically chosen because it allows simultaneous evaluation of both within-subject factors (time and measurement) and the between-subject factor (group). This statistical design aligns closely with our hypotheses, enabling assessment of the overall effectiveness of VR training as well as determination of whether training duration (8-day vs. 28-day) significantly influences cognitive outcomes across multiple testing phases (pre-test, post-test, and follow-up). Furthermore, the mixed model ANOVA facilitates examination of interaction effects, which is critical for identifying how different cognitive functions (RT, MT, EHC, TPED, AET) respond distinctly across training groups and testing points. This approach thus directly addresses our research questions concerning both the durability and specificity of cognitive improvements following VR-based training interventions. Figure 2: First-person in-game perspective of a player holding two virtual sabers (red on the left, blue on the right). Incoming blocks colored red and blue approach the player, indicating that they must be sliced with the corresponding colored saber. Arrows on each block specify the required slicing direction. Transparent rectangular obstacles are also visible, requiring players to physically dodge them by moving their bodies. On-screen indicators include the current combo streak and total score, as well as a multiplier representing score bonuses achieved by consecutive successful hits. Table 2 details the outcomes from the utilized 4 \(\times\) 3 \(\times\) 5 mixed model concerning main effects and interactions. Significant main effects were identified for group (F = 3.491, \(p\) = 0.018, \(\eta^{2}\)p = 0.105, \(\lambda\) = 10.473), measurement (F = 3628.679, \(p\) < 0.001, \(\eta^{2}\)p = 0.976, \(\lambda\) = 14,514.716), and time (F = 9.839, \(p\) < 0.001, \(\eta^{2}\)p = 0.1, \(\lambda\) = 19.678). The analysis also uncovered significant interactions of time \(\times\) group (F = 4.531, \(p\) < 0.001, \(\eta^{2}\)p = 0.132, \(\lambda\) = 27.186) and measurement \(\times\) group (F = 2.628, \(p\) = 0.002, \(\eta^{2}\)p = 0.081, \(\lambda\) = 31.535). Additionally, significant interactions were found for measurement \(\times\) time (F = 3.455, \(p\) < 0.001, \(\eta^{2}\)p = 0.037, \(\lambda\) = 27.642) and the three-way interaction of measurement \(\times\) time \(\times\) group (F = 3.163, \(p\) < 0.001, \(\eta^{2}\)p = 0.096, \(\lambda\) = 75.905). Following the initial analysis, significant within-group changes were explored, as presented in Table 3.  
In the E8 group, significant enhancements were observed in EHC (\(p\) < 0.001, F = 10.198, \(\eta^{2}\)p = 0.188, \(\lambda\) = 20.395), TPED (\(p\) = 0.001, F = 8.068, \(\eta^{2}\)p = 0.155, \(\lambda\) = 16.136), and AET (\(p\) = 0.002, F = 6.633, \(\eta^{2}\)p = 0.131, \(\lambda\) = 13.267), indicating that short-term VR training leads to notable improvements in eye-hand coordination and efficiency in cognitive-motor tasks. The moderate effect sizes (\(\eta^{2}\)p = 0.131-0.188) suggest that these improvements were