Figure 3.

Effect estimates for low-level similarity and viewpoint symmetry. a, In a given ROI, the effects of low-level similarity were estimated by correlating the upper triangle of the empirical correlation matrices of both hemispheres with a model of low-level similarity, derived from the output of a computational V1 model (shown left). The effects of viewpoint symmetry, which predict higher correlation values for viewpoints with mirror-symmetric viewing angles, were estimated based on the partial correlation between the empirical correlation matrix and the viewpoint-symmetry model (right), after first regressing out the effects of low-level similarity. b, Visualization of the average correlation matrix for the ROIs. Please note that we estimated the effect sizes for every subject individually and not based on these averages. c, The average effect sizes of low-level similarity in the different ROIs (error bars indicate SEM). All regions show significant effects. d, Average effect size of viewpoint symmetry. While higher level ROIs show significant effects of viewpoint symmetry, the early and intermediate-level areas V1–hV4 do not (see text for details and p values).