Effects of Indoor Wood Coverage Ratios on Visual Attention in Educational Environments

Visual attention plays a critical role in learning performance in educational environments, where sustained concentration is frequently required. Although wood has been widely recognized as a beneficial interior finishing material, quantitative evidence regarding the effects of indoor wood coverage on visual attention in classroom settings remains limited. In particular, the influence of different wood coverage ratios on the magnitude, spatial distribution, temporal characteristics, and inter-individual consistency of gaze behavior has not been sufficiently investigated. This study examined the effects of indoor wood coverage ratios on visual attention in classroom environments using eye-tracking analysis. A total of 32 university students participated in a within-subject experiment involving four classroom conditions with wood coverage ratios of 0%, 30%, 60%, and 90%. Participants viewed identical lecture content while wearing a wearable eye-tracking device. Visual attention was evaluated using total fixation duration, fixation count, fixation ratio, heatmap distributions, temporal gaze trajectories, and inter-individual response variability. The results showed that indoor wood coverage significantly affected total fixation duration and fixation count, whereas fixation ratio did not differ significantly among the four conditions. Wood coverage was associated with differences in total fixation duration and fixation count, although these effects did not follow a strictly graded pattern across the four conditions. The 90% condition showed fewer fixation events than the 0% condition, while the remaining pairwise differences in fixation count were not statistically significant. Heatmap analysis further demonstrated that increasing wood coverage promoted greater gaze concentration within the instructional area and reduced peripheral gaze dispersion. In addition, inter-individual variability in total fixation duration decreased as wood coverage increased, with the 90% condition exhibiting the lowest variability among the investigated environments. These findings provide objective behavioral evidence that indoor wood coverage influences not only the magnitude of visual attention but also its spatial distribution, temporal characteristics, and consistency across occupants. The results suggest that interior wood coverage can serve as an evidence-based design parameter for creating educational environments that support sustained and task-oriented visual attention.