Spatial generalization in honeybees confirms Shepard's law

In stimulus generalization, a subject that has learned to respond to one ta rget stimulus also responds to other similar stimuli. Shepard's law of gene ralization states that probability of responding decreases exponentially wi th psychological distance between test and target stimuli (Shepard, R.N., 1 987. Toward a universal law of generalization for psychological science. Sc ience 237, 1317-1323). In experiments on spatial generalization, honeybees were trained to find a target at a location near one principal landmark, an d then tested with the target at different locations. A theoretical scale o f positional mismatch between test and target locations was computed by a w eighted sum of discrepancies between test and target locations in the compa ss direction (0.25 weight) and size (angle) of projected retinal height (0. 375 weight) and width (0.375 weight) of the landmark, derived from the mode l of Cartwright and Collett (Cartwright, B.A., Collett, T.S., 1982. How hon eybees use landmarks to guide their return to a food source. Nature 295, 56 0-564; Cartwright, B.A., Collett, T.S., 1983. Landmark learning in bees. J. Comp. Physiol. A 151, 521-543) of landmark use in honeybees. Based on the theoretical scale, but not on physical distance, Shepard's law fit data fro m four experiments, the first time it has been confirmed in an invertebrate . (C) 1999 Elsevier Science B.V. All rights reserved.