Aftereffects of lithium-conditioned stimuli on consummatory behavior.

Exposure to taste or spatial cues previously paired with lithium administration resulted in more drinking during a test session started 15 min. later than did exposure to stimuli previously presented in the absence of drug treatment (Experiments 1, 2, 4, and 5). This outcome reflected an elevation of intake above baseline levels (Experiment 1) and required the presence of the lithium-paired cues rather than merely a history of lithium injections (Experiments 1, 2, 4, and 5). The increased drinking was evident in tests with novel (Experiments 1, 4, and 5) as well as familiar (Experiment 2) palatable solutions and was not attributable to a greater degree of thirst in subjects exposed to the lithium-predictive cues (Experiments 4 and 5). The phenomenon was attenuated by extinction of the lithium-conditioned stimuli (Experiment 3). However, the increased drinking aftereffect probably was not a result of the conditioned aversiveness of lithium-predictive cues, since shock-conditioned stimuli did not elicit enhanced consumption (Experiment 5). Various explanations of the effect are discussed.