Figure 20

Different patterns of evoked activity for different effective ranges of intracortical interaction in the EN model. The component 〈s _z |z(x)〉 of the orientation map z(x) in the direction of the stimulus s _z is plotted as a meshed 3D graph in a 6Λ × 6Λ patch. Color code and height of the projection below indicate the strength of activation. The stimulus is presented in the center of the displayed cortical subregion. (a) Evoked activity patterns e(x, S, z, r) for small interaction range σ/Λ = 0.1 and weakly oriented stimulus with s _z = 0.01 (left) and strongly oriented stimulus with s _z = 4 (right). rPWCs (see upper right) are optimal in this regime. (b) Evoked activity patterns e(x, S, z, r) for large interaction range σ/Λ = 0.9 and weakly oriented stimulus with s _z = 0.01 (left) and strongly oriented stimulus with s _z = 4 (right). Spatially aperiodic 8-planforms (see upper right) are optimal in this regime. A uniform retinotopy was assumed in all cases for simplicity.