The role of nonreinforcement in the learning of honeybees.

Two series of experiments with honeybees were designed to test the assumption that inhibition is generated by nonreinforcement as a function of the excitatory value of the context. In the first series (Experiments 1-3), summation tests with B were made after A+/C-/AB- as compared to A+/C-/CB- training, with precautions taken to minimize the possibility of a masking effect of excitatory within-compound conditioning on AB trials; responding to B did not vary with training procedure. In the second series (Experiments 4-5), retardation tests rather than summation tests were used, in the belief that they might be more sensitive; after A+/AB-/CD- training, acquisition in a B+/D- problem was found to be no less rapid than in a D+/B- problem. A third series of experiments (Experiments 6-9) was designed to test the more general assumption that the effectiveness of nonreinforcement increases with the excitatory value of the context; response to B was found to be no different after A+/B+/C- training followed by A+/AB- training than after A+/B+/C- training followed by A+/CB- training. The results are compatible with the view that the role of nonreinforcement in honeybees is not to generate inhibition, but only to reduce excitation in a manner independent of the excitatory value of the context.