Fig. 7. Refined model of figure-background modulation.

A We revised the a priori model from Fig. 1 by using the best-fitting regression plane shown in Fig. 4A as the connectivity matrix between V4 and V1, which is shown in 2 and 3 dimensions. The preferred figure-location for this example kernel is to the right. Other preferences were achieved by rotating the kernel. B upper panel, The overall feedback signal to V1 from V4 units preferring surfaces to the right obtained by convolving the kernel with a ‘u’ shaped figure. Lower panels, predictions of V1 activity for the a priori and post hoc model (using the kernel of A). C Neuronal data in area V1 of monkeys elicited by a textured-defined ‘u’ shape (red trace) and checkerboard pattern (blue trace) along a cross-section indicated by the red/blue line of the inset (from Self et al.⁷). The lower panel shows the difference between the conditions (identical to Fig. 1B). Red regions are regions with V1 excitation, blue regions signal V1 inhibition. D left, V1 activity according to the a priori model. Note that this dataset was not used to fit the refined model.