Odor Passive Avoidance Learning in IndividualDrosophila melanogaster:Parametric Investigations of Unconditioned Stimulus Intensity and Inter-Trial-Interval

Two studies investigated associative odor passive avoidance conditioning in individualDrosophila melanogaster.The purpose of these studies was to investigate whether variables which are known to influence associative learning in mammals would have the expected effect in the Benzer odor passive avoidance learning paradigm inD. melanogaster.The variables investigated were: 1) the Intensity of the Unconditional Stimulus (US), and 2) the Inter-Trial-Interval (ITI). The results of these studies demonstrated that the strength of an odor avoidance conditioned with electric shock as the reinforcer was a function of: 1) the intensity of the US (0, 10, 20, 40, or 80 VAC) with increasing intensities resulting in progressively increasing avoidance and 2) the length of the ITI (0, 15, 30, or 90 s), with increasing intervals resulting in greater learning, whether assessed in acquisition or extinction. The overall findings of these studies are consistent with the literature on the impact of these variables on mammalian associative learning in general and avoidance learning in particular.