## 3 Results and Discussion
### Effect of Age  
The ANOVA results revealed that there was a significant difference between age groups (F(2,47) = 10.845, \(p\) < 0.000). A Tukey analysis revealed that for the group aged less than 40 years (exclusive), the cybersickness score was significantly lower than those of the groups aged 40-59 years (\(p\) < 0.000, 95% CI = [\(-\)29.857, \(-\)10.816]) and over 60 years (inclusive) (\(p\) < 0.000, 95% CI = [\(-\)2.182, \(-\)6.141]). There was no significant difference between the groups aged 40-59 years and over 60 years (\(p\) = 0.464, 95% CI = [\(-\)4.845, 14.195]), but the average SSQ score of the group over 60 years old (30.388) was slightly lower than that of the group aged 40-59 years (35.063). Considering whether the FCACIS was used, there was a FCACIS (F(2,21) = 9.918, \(p\) = 0.001)). A Tukey analysis revealed that for the group aged less than 40 years, the average SSQ score (16.363) was significantly lower than those of the groups aged 40-59 years (43.075) (\(p\) < 0.002, 95% CI = [\(-\)41.939, \(-\)9.486]) and over 60 years (40.075) (\(p\) < 0.004, 95% CI = [\(-\)40.069, \(-\)7.616]). Although there was no significant difference between the groups aged over 60 years and 40-59 years (\(p\) = 0.955, 95% CI = [\(-\)14.356, 18.096]), the average SSQ score for the group aged over 60 years (40.205) was slightly lower than that of the group aged 40-59 years (42.075). When the FCACIS was activated, there was a significant difference across ages (F(2,21) = 5.600, \(p\) = 0.01). A Tukey analysis showed that the average SSQ score for those younger than 40 was 13.090, which was significantly lower than that of the 40-59 age group (28.050) (\(p\) = 0.008, 95% CI = [\(-\)26.227, \(-\)3.693]) but not significantly different from that of the group aged over 60 years (20.26) (\(p\) = 0.239, 95% CI = [\(-\)18.747, 3.787]). The average SSQ score of the group aged over 60 years (20.570) was lower than that of the group aged 40-59 years (28.050) but not significantly lower (\(p\) = 0.239, 95% CI = [\(-\)18.747, 3.787]). In addition, the results in Figure 10 show that the FCACIS had a greater effect on the age group over 60 years, with the SSQ score decreasing by 48.84%; for those younger than 40 years, the SSQ score was reduced by only 19.99%. That is, without the FCACIS, the age group above 40 years (including those over 60) could suffer from cybersickness due to operating in VR, and this effect was much more serious than for the age group under 40 years old (exclusive). However, when the FCACIS was enabled, it had a significant effect on reducing cybersickness in the group aged 40-59 years, and the effect was more significant in the group aged over 60 years. The reason might be that the subjects younger than 40 years (exclusive) were less likely to suffer from cybersickness and might trigger the FCACIS less often, so the FCACIS was less effective in alleviating cybersickness for this group. Figure 9: The average SSQ scores in the three major categories obtained for different sexes with and without the FCACIS. An analysis of the three major categories of the SSQ (as shown in Figure 11) revealed that subjects of different ages had the highest rate of oculomotor symptoms compared with other symptoms regardless of whether the FCACIS was enabled. When the FCACIS was activated, the total score of disorientation in the group aged over 60 years decreased the most (a decrease of 79.17%); the total score of oculomotor symptoms decreased the most in the group aged 40-59 years (a decrease of 36.00%); and in the group under 40, the total score of nausea decreased the most (a decrease of 66.64%). Overall, the FCACIS could significantly reduce the symptoms of cybersickness for people aged over 40 years (including those over 60 years). For those under 40 (exclusive), the FCACIS had limited effectiveness because it was not activated when the symptoms were mild. Figure 11: The average SSQ scores in the three major categories obtained by subjects of different ages with and without the FCACIS.