Figure 3.

A schematic illustration of how angles between neighbors are measured. Active regions are indicated with crosses over a portion of a cartoon orientation map (a). For the equivalent analysis of patch-labeling experiments, crosses would indicate the centers of identified patches. Neighbor relationships between vertices are shown as solid lines connecting neighboring crosses. The edge of the craniotomy mask is shown as a thick white line. The large cross is the vertex for which interneighbor angles will be collected. b shows an angle that meets the criteria for measurement. The white arc indicates the pair of neighbor relationships that define this angle at the vertex under analysis. Note that in all cases only the acute angle is measured, and the complementary obtuse angle is ignored. c shows an angle that does not meet the criteria for measurement. In this case, the secondary neighbor relationship that would connect the 2 primary neighbors is missing (indicated by a dashed line); the neighborhood circle for these 2 points intersects the edge of the craniotomy (see Materials and Methods).