Acquisition and retention of dark avoidance by the toad,Xenopus laevis (Daudin)

Young toads,Xenopus laevis, were trained for dark avoidance in a passive avoidance paradigm using electric shock in a fully automatic training and recording procedure. Dark avoidance was acquired within approximately 30 min and was retained on retesting 24 h later. Comparison of the performance of the toads during training and during retesting was used as an indicator for saving or reinforced retention. Control experiments demonstrated that changes in behavior were due to learning and not to nonassociative effects such as pseudoconditioning, increased sensitization to shock, or acquaintance with the testing apparatus.