# Impact of Sound and Image Features in ASMR on Emotional and Physiological Responses
## 3 Results
### EEG Analysis  
The analysis of EEG changes during video viewing revealed significant differences in the delta and the theta band between the HVLR and LVHR groups, using independent sample \(t\)-tests and Mann-Whitney U tests. As shown in Figure 4, mean power changes in the delta band differed notably between groups at the Fp2, P3, P4, C3, and T4 electrode sites, with higher values observed during LVHR video viewing compared to HVLR. In the theta band, a statistically significant difference emerged at the O2 site, while the O1 site exhibited a meaningful trend without reaching statistical significance. Theta wave activity in the occipital region displayed greater mean power changes during LVHR video viewing compared to HVLR. Figure 5 provides a comparison of activation levels across brain regions and frequency bands for both groups.  
Figure 2: This figure illustrates the comparison of mean arousal and positive affect scores between the HVLR and LVHR group videos. The average arousal score for the HVLR group was 3.36 (SD = 1.219), compared to 1.81 (SD = 1.166) for the LVHR group. Similarly, the mean positive affect score for the HVLR group was 3.54 (SD = 1.115), while it was 2.64 (SD = 1.315) for the LVHR group.  
Figure 4: This figure illustrates significant differences in the average brainwave power between the HVLR group and the LVHR group across several EEG variables. Notable differences were identified in delta wave activity at the Fp2 (F = 0.003, T(6) = \(-\)2.877, \(p\) = 0.028), T3 (F = 7.988, T(4.608) = 2.056, \(p\) = 0.100), T4 (F = 4.221, T(6) = 2.570, \(p\) = 0.042), P3 (U = 0, z = \(-\)2.309, \(p\) = 0.029), P4 (U = 0, z = \(-\)2.309, \(p\) = 0.029), C3 (U = 0, z = \(-\)2.309, \(p\) = 0.029), and O2 (F = 3.273, T(6) = 1.977, \(p\) = 0.095) electrode sites, as well as in theta wave activity at the O1 (F = 0.048, T(6) = 2.224, \(p\) = 0.068) and O2 (F = 0.014, T(6) = 3.251, \(p\) = 0.017) sites. (*: \(p\) < 0.05).  
Figure 3: This graph presents the results of a cross-analysis of emotional vocabulary between the HVLR and LVHR groups. For the HVLR group, the most frequently selected emotional terms were “vibrant” (37.90%), “enjoyable” (18.35%), and “pleasant” (12.90%). In contrast, for the LVHR group, the most chosen words were “calm” (37.90%), “comfortable” (17.74%), and “relaxed” (17.74%). The results were statistically significant (Pearson chi-square test, X\({}^{2}\)(8, \(n\) = 248) = 138.002, \(p\) = 0.000).  
Beta wave activity was more prominent at the C3 and C4 sites compared to other locations, displaying a meaningful trend despite lacking statistical significance (F = 0.014, T(6) = \(-\)2.170, \(p\) = 0.073). Specifically, the HVLR group exhibited greater activation at C3, while the LVHR group showed higher activation at C4. The difference in power values between the HVLR and LVHR groups was more pronounced at C3 than at C4, highlighting a distinctive trend in beta band activation patterns across these electrode sites.  
As presented in Table 3, the asymmetry index (AI) was generally positive across all brain regions, indicating greater right hemisphere activation. Specifically, at the Fp sites, the AI values for all frequency bands exceeded 0.2 for both LVHR and HVLR group videos. At the C sites, the AI for the alpha and beta bands was greater than 0.2 during the viewing of LVHR group videos, whereas, at the T sites, the AI for the beta band exceeded 0.2 during the viewing of HVLR group videos. At the O sites, the AI for the beta band was above 0.2 for both LVHR and HVLR group videos. Conversely, the absolute AI values were calculated to be below 0.05 in the delta and theta bands at the T sites and in the theta band at the O sites, irrespective of the video type.