Contextual modulation of visuomotor associations in bumble-bees (Bombus terrestris)

We performed the following experiment to investigate whether contextual cue s can prevent interference during the acquisition of potentially competing visuomotor associations in the bumble-bee (Bombus terrestris). Bees discrim inated between horizontally and vertically orientated gratings of black and white stripes in order to reach a feeder and between different diagonally orientated gratings to gain access to their nest. Once bees were well train ed on these two tasks, the discrimination task at the nest was changed so t hat bees had to distinguish between horizontal and vertical gratings at bot h sites. Whereas they still approached the horizontal grating to reach food , they now had to approach a vertical grating in order to return to their n est. The new task was learnt rapidly Errors at the feeder did not increase during or after the acquisition of this potentially competing behaviour at the nest entrance. For a brief period during acquisition, bees showed some hesitation at the feeder and hovered for slightly longer before choosing be tween horizontals and verticals. After acquisition was complete, bees showe d a slight increase in their preference for verticals over a more ambiguous stimulus of an array of dots. These findings are consistent with the hypot hesis that different contextual signals are associated with approaching the nest or approaching the feeder, and that these contextual signals facilita te learnt associations between orientation detectors and motor commands.