Working memory and concept learning in honeybees

Abstract

There are a large number of studies that show that the basic learning of honeybees is comparable to that of vertebrates. The similarities of learning between honeybees and vertebrates are rather remarkable given the differences in their nervous systems and their evolutionary history. Propelled by the findings of the initial learning experiments, recent research with honeybees has explored more complex learning phenomena, or cognitive phenomena, such as working memory and concept learning. In all of the experiments reported here, the free-flying procedure was used to study working memory and concept learning in honeybees. In this procedure, free-flying honeybees were individually trained to shuttle between a laboratory window and the hive. The experiments reported in Section 1 focus on working memory in honeybees. Typical two-stimulus matching-and nonmatching-to-sample problems were used with short (Experiment 1) and long (Experiment 2) delays. The results showed that honeybees have working memory that lasts for up to 2-3 min. The experiments reported in Section 2 focus on same-different concept learning in honeybees. Trial-unique simultaneous matching-and nonmatchingto-sample problems were used with sample reward (Experiment 3) and without sample reward (Experiment 4). Although the results can be considered as evidence of samedifferent concept learning, a perceptual discrimination account cannot be rejected. The experiments reported in Section 3 also focus on same-different concept learning but now with a working memory procedure in order to exclude a perceptual account. Trial-unique matching-and nonmatching-to-sample problems were used with short (Experiment 5) and long (Experiment 6) delays. The results with the short delays showed same-different concept learning while the results with the long delays did not. The two major findings of the present experiments, long working memory and same-different concept learning, are discussed from both a comparative psychology and an ecology perspective. Instead of using matching-to-sample variants, future work on same-different learning should use other procedures such as oddity learning and simultaneous and successive discrimination problems. Results of future experiments may shed light on the generality and extensiveness of same-different concept learning in honeybees.