Hierarchical cluster analysis. (A) Dendrogram from the hierarchical cluster analysis of the 'content' population tested with Random stimuli (n = 40 cells). Each horizontal branch represents a stimulus (first number) with one direction of illumination (B, L, R or A). Clusters A and B are separated by a linkage distance (d) of 170. At a second level (d = 38), A branch splits into 2 clusters A1 and A2. Each color corresponds to one type of stimuli (3D, Blobs, Random or Posterized). (B) Dendrogram from the hierarchical cluster analysis of the 'content' population tested with Posterized stimuli (n = 53 cells). Same conventions as A.