Fig 1.
Schemas of the 3D object used in this study.
Surface B is the bottom face and surfaces A and C are vertically oriented. Participants judged the brightness of surfaces A and B, but we did not use surface C as a target because it appeared very narrow in both conditions.
Fig 2.
Schemas of how participants perceived the stimulus pattern.
The dotted quadrangle shows the actual position and the gray one shows the perceived position. In the concave condition, all surfaces are observed as inside faces of the object and it is seen as horizontal and concave, corresponding to its actual structure. In the convex condition, all surfaces are observed as outside faces of the object and it is seen as vertical and convex, similar to the shape of a building (see also Fig 1).
Table 1.
Actual Munsell values and luminance values (cd/m2) of surface.
Fig 3.
Participants’ matches to surfaces A and B in Experiment 1. Each data point represents the mean matched Munsell value for each respective condition, and error bars show standard error.
Fig 4.
Differences between surfaces A and B for matched Munsell values in Experiment 1. We took the differences between the data for surfaces A and B shown in Fig 3. Error bars show standard error.
Fig 5.
Participants’ matches for surfaces A and B in Experiment 2. Each data point represents the mean matched Munsell value for each respective condition, and error bars show standard error.
Fig 6.
Differences between surfaces A and B for matched Munsell values in Experiment 2. We took the differences between the data for surfaces A and B shown in Fig 5. Error bars show standard error.