SYMMETRY PERCEPTION IN AN INSECT

SYMMETRICAL visual patterns have a salient status in human perception, as evinced by their prevalent occurrence in art(1), and also in anima l perception, where they may be an indicator of phenotypic and genotyp ic quality(2-4). Symmetry perception has been demonstrated in humans(5 -8), birds(9-11), dolphins(12) and apes(13). Here we show that bees tr ained to discriminate bilaterally symmetrical from non-symmetrical pat terns learn the task and transfer it appropriately to novel stimuli, t hus demonstrating a capacity to detect and generalize symmetry or asym metry. We conclude that bees, and possibly flower-visiting insects in general, can acquire a generalized preference towards symmetrical or, alternatively, asymmetrical patterns depending on experience, and that symmetry detection is preformed or can be learned as a perceptual cat egory by insects, because it can be extracted as an independent visual pattern feature. Bees show a predisposition for learning and generali zing symmetry because, if trained to it, they choose it more frequentl y, come closer to and hover longer in front of the novel symmetrical s timuli than the bees trained for asymmetry do for the novel asymmetric al stimuli. Thus, even organisms with comparatively small nervous syst ems can generalize about symmetry, and favour symmetrical over asymmet rical patterns.