Figure 4a illustrates the mean SVV errors across participants as a function of scene orientation for each room aspect ratio, where each curved line represents the mean of the best model fits obtained. The mean SVV errors varied as a function of scene orientation and aspect ratio. Each curved line in
Figure 4a represents the mean of the best model fit obtained. We also plotted the mean length of each visual vector obtained for each participant and each room aspect ratio (
Figure 4b). There was a linear increase in the vector length of the 180° component, whereas the length of the 90° component increased more gently.
A two-way repeated-measures ANOVA with periodicity (45°, 90°, and 180°) and room aspect ratios (1.2, 1.5, and 2) as within-participant variables revealed a significant main effect of room aspect ratio, F(1.7, 49.31) = 4.88, p = 0.016, η2 = 0.004, and periodicity, F(1.32, 38.18) = 94.16, p < 0.001, η2 = 0.566. The interaction between them was not significant, F(3.32, 96.19) = 1.46, p = 0.227, η2 = 0.003. The multiple-comparison tests illustrated that the vector length for the smallest room aspect ratio (1.2) was significantly lower than that for the widest aspect ratio condition, t(29) = 2.61, p = 0.042, d = 0.33. The comparisons between 1.2 and 1.5, t(29) = 1.51, p = 0.141, d = 0.140, and the comparisons between 1.5 and 2, t(29) = 1.97, p = 0.0582, d = 0.193, were not significant. The multiple comparison demonstrated the largest contribution of the 90° component compared with 45°, t(29) = 9.96, p < 0.001, d = 1.616, and 180°, t(29) = 10.38, p < 0.001, d = 2.030). The 45° and 180° components were not significantly different from each other, t(29) = 1.80, p = 0.082, d = 0.437.
In summary, the influence of visual periodicity cues on the SVV error increased with room aspect ratio size. We found no evidence that the influence of the room aspect ratio was specific to a particular periodicity. Finally, the contribution of the 90° component was much greater than that of the 45° and 180° components.