Fig 7. Principal component analysis of odor patterns in the OG of the AL reveals that the response patterns to sunflower and ylang-ylang, respectively, are more separated after the pheromone pairing than before.

This occurred both when sunflower and ylang-ylang was paired with pheromones (A and B, respectively). The biplot contains scores of each ordinary glomerulus (black numbers) and loading of each odor pattern (colored vectors) on the first 2 principal components (explaining 84–94% of the variance).