Figure 3. Orientation columns exhibit an invariant aggregate receptive field structure.

a, Consistent with simple cells in other mammals, the ON/OFF subfield displacement in visual space predicts the preferred orientation in individual cells (linear regression, N = 176 cells from 2 animals, P < 0.0001). b, Example of receptive fields from the simple cells in a single orientation column (dashed circle). Lines connect the ON subfield (red) and the OFF subfield (blue) centers of individual simple cell receptive fields. The ON centers form two clusters that define the aggregate ON-dipole of the column. c, The aggregate ON- dipoles from all the simple cells within individual orientation columns predicts the preferred orientation of the column (linear regression, P < 0.0001). d, The normalized simple cell receptive fields from a single column in b were averaged to derive the aggregate receptive field (ARF) which was fit with a Gabor. e, Cortical columns exhibit an invariant ARF structure resembling an OFF centered simple cell receptive field with specific relative phase, number of half-cycles, and aspect ratio. f, The parameters of the ARF Gabor fit account for multiple features of the cortical column including orientation, visual position, and spatial frequency (N = 73 cortical columns from 5 animals, circular or linear regression, all P < 0.0001; see Methods).