Motivational state-dependent renewal and reinstatement of operant responding under food and water deprivation states.

Most studies of operant relapse phenomena have studied the role of exteroceptive discriminative features of context in the recovery of behavior after extinction. Interoceptive stimuli (i.e., stimuli arising from the bodies of organisms) may also serve as a part of learning contexts and contribute to relapse. Recent studies have demonstrated that events that function as motivating operations (MOs) may contribute to relapse both by a) eliciting interoceptive conditions that serve as a discriminative context for relapse (i.e., discriminative function) and b) altering the amount of operant responding in the presence of discriminative stimuli associated with reinforcers (i.e., motivational function). The current study examined interactions between these functions of food and water deprivation MOs in the relapse of operant behavior. During acquisition of an operant response, one group of mice was food-deprived and another was water-deprived. The groups then received extinction sessions under the opposite condition. Renewal and reinstatement tests were conducted under both conditions, and more renewal and reinstatement were observed in the motivational states in which acquisition occurred for each. These results are discussed in the context of state-dependent learning.

Interactions between the effects of food and water motivating operations on food- and water-reinforced responding in mice.

Two experiments examined interactions between the effects of food and water motivating operations (MOs) on the food- and water-reinforced operant behavior of mice. In Experiment 1, mice responded for sucrose pellets and then water reinforcement under four different MOs: food deprivation, water deprivation, concurrent food and water deprivation, and no deprivation. The most responding for pellets occurred under food deprivation and the most responding for water occurred under water deprivation. Concurrent food and water deprivation decreased responding for both reinforcers. Nevertheless, water deprivation alone increased pellet-reinforced responding and food deprivation alone likewise increased water-reinforced responding relative to no deprivation. Experiment 2 demonstrated that presession food during concurrent food and water deprivation increased in-session responding for water relative to sessions where no presession food was provided. Conversely, presession water during concurrent food and water deprivation did not increase in-session responding for pellets. These results suggest that a) the reinforcing value of a single stimulus can be affected by multiple MOs, b) a single MO can affect the reinforcing value of multiple stimuli, and c) reinforcing events can also function as MOs. We consider implications for theory and practice and suggest strategies for further basic research on MOs.