Overview of effects of surface luminance on the perceived layout of interior space, as a function of the room surface that was varied in luminance, and the room dimension that was judged by the observers.

indicates the mean simulated size of the judged spatial dimension. Yb and Yd indicate the luminance of the brightest and the darkest presented surface color, respectively. The difference in perceived brightness (ΔB), the mean difference in perceived spatial extent (), and Cohen's [37] dz are reported for the comparison of the brightest and darkest presented surface color. We calculated the difference in perceived brightness between the dark and the bright stimulus by ΔB = Yb0.33−Yd0.33, where the power function links the perceived brightness B to the physical luminance Y (e.g., [39], see also [40,41]). Bold dz-values indicate significant effects (p < .05). Effects of bounding-surface luminance are highlighted by a gray background.