CONDITIONAL VISUAL DISCRIMINATIONS AND SYMMETRY PROBES IN MELIPONAS

Abstract

Eight adult, worker bees (Melipona quadrifasciata) were exposed to an adapted version of the matching- to-sample procedure in which the presence or absence of lights was used as the conditional stimuli and yellow and blue colors were the discriminative stimuli. The color stimuli were presented as semi-circles of opaque rubber material located on top of two rectangular boxes, located 15 cm apart from each other. The lights were located oneabove each box. The experimental boxes were custom-made, constructed of gray plexiglass with an aluminum top panel. Each box was equipped with a feeder operated from outside by a handle and small holes on a circumscribed area on the top gave access to syrup. The bee would fly from the hive to the experimental setting and would obtain syrup conditional upon flying to the box holding the comparison stimulus defined as S+ on a particular trial. After the baseline was established, symmetry probes interspersed with baseline trials were conducted in extinction. During the symmetry probes the colored disks had the function of conditional stimuli (the two boxes held disks of the same color, either blue or yellow) and the presence and absence of light were used as discriminative stimuli. The conditional discriminations were established with all bees and six out of eight reached the criterion for emergent symmetry (at least five trials out of six). These results extended previous findings for conditional discriminations and identity matching with bees. For symmetry tests, however, in the present procedure the stimuli had fixed positions, an issue which raises questions as to whether the observed behavior reveals symmetric (emergent) properties or just (learned) joint-control by components of a compound stimulus. Key words: conditional discriminations, symmetry, bees (Melipona quadrifasciata).