Figure 3: Orientation preference is dependent on retinotopic position.

(a) Image of GCaMP6 fluorescence in the sSC after neocortex has locally been aspirated. (b) Retinotopy in sSC. Each pixel is coloured corresponding to the monitor patch to which it gave most response. Pixel saturation scales linearly with response strength. Maximum ΔF/F was 8%. A smooth mesh was drawn over the boundaries of the monitor patch representations. This mesh was added to the other panels only as a visual aid. Scale bar is 1 mm. (c) The difference of the average response for each set of orientations and the average response to all orientations shows regional differences, which are very consistent for the first set of 10 (left) and next set of 10 presentations (right). (d) Left top panel shows polar map of sSC, where each pixel is coloured to its angular preference. Saturation scales linearly with response strength. Maximum ΔF/F was 7%. The map shows a smooth change covering all angles once. For the four indicated locations (each disk with a radius of 40 μm, covering area of 40 pixels) at different corners of the responding region, the response to all directions are shown at the bottom. Error bars in tuning curves are mean±s.e.m. Right top panel shows the significance of the preference of each sSC pixel for any of the four orientations. P-values of the white pixels are less than 0.05. (e) For each patch in the retinotopy of b, the preferred orientation is computed and shown on the equivalent part in visual space. This reveals a preference for concentric orientations.