Figure 3.

(A,B) The direction vectors from a minimal population of two cells are combined into a population vector. Each cell codes for a particular movement direction and the responses of the two cells weigh together the two vectors into a combined population vector that corresponds to the subsequent movement direction. When the response of cell 2 is higher than that of cell 1, the population vector will point in a direction that is closer to vector 2 than that of vector 1. When cell 1 has the higher response, the population vector will be more aligned with vector 1. (C) A hypothetical face space of the type found by Young and Yamane (1992). Different faces are arranged along two dimensions where faces that are similar to each other are located close to each other in the space.