Figure 5.

Time course of receptive fields from a disynaptically connected ON-center RGC and a cortical simple cell. A, Smoothed spatial receptive field maps (256 × 256 pixels, linear-interpolated; see Materials and Methods). B, Raw maps (16 × 16 pixels) used to generate smoothed maps in A and to compute response time courses of the four ON pixels (B, within yellow squares) that are common to both the RGC and V1 cells. Grid lines show individual stimulus pixels (0.75°). C, Impulse responses, or response time courses, of an RGC (green curve) and V1 cell (black curve). Both responses peaked at the same time (23 msec), but the zero crossing time of the V1 response is 22 msec slower than the RGC.