## 2 Materials and Method
### Experimental Environment  
The experimental laboratory was constructed within a real SUV vehicle, offering an interior space measuring 420 cm in length, 180 cm in width, and 140 cm in height. This vehicle was placed in a sealed, darkened room, with every wall lined with non-reflective materials, located in Shanghai Emerald Garden. To ensure strict control over the lighting conditions inside the vehicle, a non-reflective curtain was draped over the vehicle's roof, effectively isolating the interior light environment. Originally, the Lixiang One features three rows of seating: the first row comprises the driver and front passenger seats, the second row consists of two individual passenger seats, and the third row includes two auxiliary seats. To maintain stringent control over the experimental variables, the interior was subdivided into four equally sized compartments using opaque acrylic boards, which prevented participants from seeing or interacting with each other. The third row was omitted from the study due to its inconsistency with the seating arrangement in the other rows. For efficient experiment management and participant communication, four wired walkie-talkies were installed within the vehicle. Additionally, audio cues for the d2 Test of Attention were transmitted through these devices. The lighting setup in the controlled laboratory featured both direct and indirect light sources. The indirect lighting was positioned along the periphery of the partitioned spaces, utilizing a blend of red, green, blue, warm white (3000 K), and cold white (6000 K) LED sources integrated into a single unit and encased within a silicone light strip. Each LED type could be adjusted individually, allowing for a wide range of illuminance and CCT adjustments. The direct lighting comprised two LED lamps suspended from the vehicle's ceiling, also incorporating red, green, blue, warm white (3000 K), and cold white (6000 K) LEDs. Throughout the experiment, various combinations of these LED sources were employed to achieve the desired lighting conditions. A diagram of the laboratory layout is provided to illustrate the experimental setup in Figure 1.  
In our study, we designated the desk area as the primary focus for lighting assessment, selecting one central point along with four corner points for the measurement of lighting parameters to ensure uniform illuminance across the area. Throughout the experiment, the Color Rendering Index (CRI) was maintained above 79, indicating a light source that basically renders colors compared to natural light [35]. The uniformity of illuminance was kept above 0.7, ensuring that light distribution was even and consistent. Subjective \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Item** & **Question** & **Very Dissatisfied** & **Slightly Dissatisfied** & **Moderate** & **Slightly Satisfied** & **Very Satisfied** \\ \hline \multirow{3}{*}{1} & Overall satisfaction when & & 1 & 2 & 3 & 4 & 5 \\  & using VDT & & & & & & 5 \\ \multirow{3}{*}{2} & Reading experience & & 1 & 2 & 3 & 4 & 5 \\  & satisfaction on VDT & & & & & & 5 \\ \multirow{3}{*}{3} & Perceived brightness & & & & & & 5 \\  & satisfaction when using VDT & & & & & & 5 \\ \multirow{3}{*}{4} & Overall satisfaction when & & 1 & 2 & 3 & 4 & 5 \\  & using paper materials & & & & & & 5 \\ \multirow{3}{*}{5} & Reading experience & & 1 & 2 & 3 & 4 & 5 \\  & satisfaction on paper & & & & & & 5 \\ \multirow{3}{*}{6} & Perceived brightness & & & & & & 5 \\ \multirow{3}{*}{6} & satisfaction when using & 1 & 2 & 3 & 4 & 5 \\ \multirow{3}{*}{paper materials} & & & & & & & 5 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Questionnaires of preference. assessments of glare categorized it as 'nearly no glare,' highlighting the effectiveness of our lighting design in minimizing discomfort. The distribution of illuminance on the desk was configured to derive 80 percent from direct lighting sources and 20 percent from indirect lighting, optimizing the balance between task lighting and ambient lighting.