Figure 2.
Speed-tuning and spatiotemporal response fields of a representative V1 simple cell (A–D) and complex cell (E–H). A, B, E, F, Plots of firing rate as a function of stimulus speed; different symbols show data obtained at three different spatial frequencies. A and E show responses at 32% contrast, and B and F show responses at 8% contrast. Curves were obtained by fitting Equations 2 and 3 to the data. C, D, G, H, Contour plots showing spatiotemporal response fields. The intensity at each combination of spatial and temporal frequency indicates the relative response, in which darker regions indicate larger responses. C and G show responses at 32% contrast, and D and H show responses at 8% contrast. The speed-tuning curves at the left were derived from the same data used to create the contour plots on the right. In the speed-tuning curves in A and B, squares, triangles, and circles show data for spatial frequencies of 0.5, 1, and 2 cycles/°. In G and H, squares, triangles and circles show data for spatial frequencies of 1.32, 2.64, and 5.28 cycles/°.
