FIG. 12.

Distribution of the indices I_shape(L^cart, E ^cart) and I_shape(L^polar, E ^polar) (Eq. 10). Values near 1 indicate consistency with a single-pathway linear–nonlinear (LN) model; significant departures from 1 indicate that spatial differences in the 2 filters L and E of Fig. 4 are required to account for the data within a single basis set. Significance levels (for I_shape <1) indicated as in Fig. 7. Each column contains calculations based on a different response measure.