Shape Perception in the Honeybee: Symmetry as a Global Framework

This study is concerned with the honeybee's spatial vision in light of the spatial signals that natural flowers display. A large amount of behavioral data shows that bees are perfectly adept at learning and exploiting a variety of spatial cues in the task of recognizing and discriminating between visual stimuli. These cues include spatial frequency, distribution of contrasting areas, orientation of contours, size and distance, different types of edges, and symmetry (or, in a broader sense, geometry). Symmetry constitutes a global feature that is only one of the cues that the target offers. Symmetrical stimuli always contain several further spatial cues that become relevant as the bee comes nearer to the stimuli. The results reviewed here show that the spatial signals used by the bee depend on whether the stimuli are presented on a horizontal or a vertical plane, on whether bees make their choices at a lesser or a greater distance, and on whether the target's image is stationary at the level of the eye, as opposed to moving. Further, it is shown that pattern recognition in the bee does not always require a learning process (i.e., several types of response to visual stimuli are based on hard-wired, innate behavioral programs). Finally, the results show that although it is not a prerequisite for spatial vision, color vision participates in spatial vision, whereas spatial cues extracted from image motion are processed by a color-blind system.