FIG. 9.
Space/space/time model for the generation of a directional simple cell and its predicted interaction maps. See METHODS for model details. A and B: diagram of 2 possible sequences for generating a cell with both orientation and direction selectivity: orientation selectivity is generated before direction selectivity (conventional energy model, A) or direction selectivity is generated before orientation selectivity (B). In A–D, red indicates light excitation/dark suppression and blue indicates dark excitation/light suppression. In E and F red indicates facilitatory interactions and blue indicates suppressive interactions. See text for details.