In orientation map of the striate cortex (V1), orientation preferences of neurons change smoothly clockwise or counterclockwise around pinwheel centers. In a previous study, we made a prediction on the basis of a geometric model of V1 orientation map that the degree of extra-receptive field contextual modulation is greater for neurons with a larger distance from its nearest pinwheel center (Okamoto et al. SFN 2003). This topography of contextual modulation derives from a characteristic distribution pattern of neurons preferring iso- and cross-orientation; at a cortical site distant from a pinwheel center, as one moves from the site farther way, relative areas of domains preferring iso-orientation and those preferring cross-orientation change periodically. This tendency becomes weaker for a cortical site near a pinwheel center. The computational model is based on an idealized, honeycomb-like arrangement of orientation preferences. Here we addressed whether orientation maps from monkey V1 exhibit the distrib...