# Vocabulary Retention Under Multimodal Coupling Strength Index (MCSI): Insights from Eye Tracking
## 4 Results
### Effect of Visual Stimuli on Lexical Memory  
For the investigation of visual stimulus effects on lexical memory, strict variable control was implemented during comparative analyses. The presence/absence of visual stimuli served as the independent variable for evaluating differences in both memory performance and fixation duration. Figures 9 and 10 present comparative thermograms for Group A/B and Group C/D, respectively.  
The Group A/B comparison showed a substantial accuracy improvement (59.60% to 82.10%; MD = 22.50%, F = 50.21, \(p\) < 0.001, \(\eta^{2}\) = 0.62). Notably, high-accuracy participants (>75% correct) increased from 41% (Group A) to 78% (Group B), indicating that pictorial cues substantially enhanced lexical memory. Group C/D exhibited further improvement when visual stimuli complemented existing auditory support (76.00% to 92.00%; MD = 16.00%, F = 47.87, \(p\) < 0.001, \(\eta^{2}\) = 0.58), with the complete data presented in Table 8.  
The implementation of visual stimuli elicited significant attentional redistribution and memory optimization effects. Specifically, Group A maintained prolonged engagement in the T1 region (M = 62.50 s, SD = 2.50) relative to Group B (M = 58.00 s, SD = 2.30), showing a 7.2% decrease with a moderate effect size (F = 4.261, \(p\) = 0.04, \(\eta^{2}\) = 0.13). More strikingly, visual stimulation induced attentional reallocation from the T2 region in Group A (M = 32.50 s, SD = 2.40) to the P region in Group B (M = 37.20 s, SD = 2.20), representing a 14.5% increase with a stronger effect magnitude (F(1,28) = 4.913, \(p\) = 0.027, \(\eta^{2}\) = 0.17).,  
\begin{table}
\begin{tabular}{c c c c c c} \hline
**Group** & **Group Segmentation** & **ASC** & **SD-SC** & **F** & \(p\) \\ \hline \multirow{3}{*}{A/C} & A & 259.90 & 7.56 & \multirow{3}{*}{0.001} & \multirow{3}{*}{0.974} \\ \cline{2-2} \cline{5-6}  & C & 259.40 & 6.98 & & \\ \cline{2-2} \cline{5-6}  & B & 265.04 & 7.27 & \multirow{3}{*}{16.066} & \multirow{3}{*}{\textless{0.001}} \\ \cline{2-2} \cline{5-6}  & D & 236.52 & 7.15 & & \\ \hline \end{tabular}
\end{table}
Table 7: Analysis of the effect of sound on the number of eye beats.  
Figure 10: Comparison of thermograms of group C/D.  
demonstrating significant attention reallocation that strongly correlated with accuracy improvement, with the complete data presented in Table 9.  
Crossmodal synergy analysis revealed distinct cognitive profiles between conditions. Group D demonstrated a significantly compressed T1 region dwell time (M = 53.80 s, SD = 2.00) compared to Group C (M = 62.50 s, SD = 2.40), reflecting a 13.9% reduction with a large effect size (F = 14.332, \(p\) < 0.001, \(\eta^{2}\) = 0.31). Conversely, Group D exhibited enhanced P region engagement (M = 36.60 s, SD = 1.90) versus the T2 region fixation of Group C's (M = 29.20 s, SD = 2.10), constituting a 25.3% increase (F= 12.616, \(p\) < 0.001, \(\eta^{2}\) = 0.28). Notably, Group D demonstrated significantly improved accuracy despite reduced word area attention time, indicating enhanced lexical memory efficiency through audiovisual integration (complete data in Table 10).