Stimulus magnitude effects on the extinction of conditioned consummatory responses to flavored sucrose solution in mice

PELLEGRINI, S

BEHAVIOURAL PROCESSES

ELSEVIER SCIENCE BV

Año: 2011

0376-6357

Paradoxical extinction effects in the conditioned consummatory behavior of rodents have remained largely elusive. Here, appetitive flavor conditioning was studied to determine if a paradoxical magni- tude of reinforcement extinction effect (MREE) can occur in the consummatory behavior of mice. During acquisition training of two experiments with factorial design, animals received daily access to either 32% or 4% sucrose solution, and goal tracking time was measured in one-minute bins. In Experiment 1 the solutions were flavored with either 5% or 0.5% almond essence and in Experiment 2 with 2% almond essence, but combined with continuous or partial schedules of reinforcement. During extinction tests of Experiment 1 and 2, water flavored with 0.5% or 2% almond was presented, respectively. Consummatory performance decreased more abruptly during the initial portion of the extinction sessions after training with 32% as compared to 4% sucrose solution. Furthermore,whengiven a choice test after extinction train- ing (Experiment 2), animals trained with 32% sucrose, preferred the flavored solution, but animals trained with 4% preferred the unflavored solution. These results are interpreted as indicative of the occurrence of a paradoxical MREE in conditioned consummatory behaviors.