Figure 11.

Two dimotif dot lattices. In both, grouping by proximity favours a, but more weakly in the dot lattice on left, where |a| = 1.25|b|, than in the dot lattice on the right, where |a| = 1.5|b|. In the dot lattice on the left, grouping by similarity favours b3 (δ > 0, where δ is a measure of dissimilarity between two kinds of dots), whereas in the dot lattice on the right it favours a (δ < 0), but because the differences between dot-colours are smaller on the left than on the right, the strength of the grouping by similarity (δ = 2) on the left is smaller than the strength of grouping by similarity on the right (δ =− 3).