Pattern learning by honeybees: conditioning procedure and recognition strategy

In recognizing a pattern, honeybees, Apis mellifera, may focus either on it s ventral frontal part, or on the whole frontal image. We asked whether the conditioning procedure used to train the bees to a pattern determines the recognition strategy employed. Bees were trained with the same patterns pre sented vertically on the back walls of a Y maze. Conditioning was either ab solute, that is, bees should learn to choose a rewarded pattern when there is no alternative, or differential, that is, bees should learn to choose a rewarded pattern that is paired with a different, nonrewarded one. Bees use d different pattern recognition strategies depending on the conditioning pr ocedure: absolute conditioning restricted recognition to the lower half whi lst differential conditioning extended it to the whole pattern. Bees traine d with absolute conditioning saw and learned the features of the upper part of the trained patterns, but assigned more weight to the lower part. Bees trained with differential conditioning learned not only the features of the reinforced stimulus in an excitatory way, but also those of the nonreinfor ced one in an inhibitory way. Thus, conditioning tasks that involve not onl y excitatory acquisition of the conditioned stimulus per se, but also discr imination of nonreinforced stimuli, result in an increase in the visual fie ld assigned to the recognition task. Conditioning tasks that involve only e xcitatory acquisition of the rewarded stimulus result in a higher weighting of the lower pattern half and thus in a more reduced field assigned to the recognition task. This difference may reflect;that existing between a cond itioned and an incidental behavioural modification. (C) 1999 The Associatio n for the Study of Animal Behaviour.