## 3 Results
### Specific Findings
#### 3.2.2 Driver Emotion Modulation Based on Unisensory and Multisensory Inputs
Consistent with previous analyses, the influenced behaviors include driving performance (\(n=29\), 85%), such as improved speed control, decreased driving errors and lane excursions [55], and improved driving performance resulting from physiological changes [53; 66]. Haptic assistance: Ref. [59] demonstrated that driver emotion modulation generally reduces stress and aggressive driving behaviors among drivers. From a tactile perspective, refs. [52; 53] found that haptic feedback not only effectively reduces stress, but is also preferred by drivers. Notably, ref. [54] mentioned that haptic feedback can increase both the rate and intensity of breathing, as well as heart rate; most participants considered the haptic breathing guidance intervention safe, provided it was not used in inappropriate scenarios. Visual assistance: From a visual viewpoint, refs. [56; 57; 58; 59] reported that exposure to pleasant images and colors, such as cool blue and warm orange, leads to slower mean driving speeds, whereas unpleasant images correlate with a higher frequency of lane excursions. Refs. [11; 15; 82] confirmed that positive expressions yielded better outcomes than negative ones in terms of expression attributes. Additionally, ref. [59] found that distractions were primarily caused by 'dislikes' encountered on the road and that ambient lighting also played a role. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Reference** & **Sensory** & **Driver** & **Driving** & **Measurement** & **Effectiveness of Driver Emotion** & **Cultural** & **Human** \\  & **Inputs()** & **Emotion(s)** & **Performance** & & **Modulation** & **Factors** & **Factors** \\ \hline
[74] & vocal & negative & DP \(\downarrow\) & scale & noise levels increased; annoyance linearly & & \\  & & & & & increased; 55 dB(A) was the best & & \\  & & & & environmental noise level for cognitive & & \\  & & & & efficiency in cognitive tasks & & & \\ \hline
[75] & cooling & negative & DP \(\downarrow\) & scale & 85\% of drivers liked cooling, which they & & \\  & & & & all believed reduced fatigue, and 91\% & & & \\  & & & & preferred it during monotonous driving & & & \\ \hline
[76] & olfactory & negative & DP \(\downarrow\) & scale & rose sent relaxed drivers; peppermit & & \\  & & & & increased alertness but caused more lane & & \\  & & & & deviations; unpleasant scents led to more & & \\  & & & & collisions & & & \\ \hline
[77] & olfactory & negative & DP \(\downarrow\) & visual & peppermit sent was effective in alerting & & \\  & & & & drivers to drowsy driving & & & \\ \hline
[78] & olfactory, & & & & olfactory notifications resulted in & & \\  & & & & significantly slower driving & & \\ \hline
[79] & olfactory & negative & DP \(\downarrow\) & scale & olfactory notifications were less & & \\  & & & & distracting and more effective than visual & & \\  & & & & ones & & \\ \hline
[80] & olfactory & negative & DP \(\downarrow\) & ECG, PPG, & & agarwood had the best effect, followed by & & \\  & & & RESP & sweet orange, with lavelender being the & & \\  & & & & least effective & & \\ \hline
[81] & reappraisal & negative & DP \(\downarrow\) & scale & drivers with fewer offenses habitually & & \\  & & & & adopted more adaptive driving styles and & & individual \\  & & & & emotion modulation strategies & & \\ \hline  & & & & & & \\ \end{tabular} Note: DP: driving performance; PR: physiological response; LE: lane excursion; BR: breathing rate; HR: heart rate; ER: error rate; SCR: skin conductance response; ET: eye tracking; \(\downarrow\): decrease; \(\uparrow\): increase.  
\end{table} 
Table 2: _Cont._From an auditory perspective, the modulation effects are twofold, involving speech and music. Empirical evidence suggests that strategies using voices and empathetic assistants are most effective in improving negative emotional states [15; 59; 61; 72]. Compared with a dominant voice, a submissive voice tends to better influence driving modes and trust [60; 67].