Two profiles in the recovery of reward devaluation in rats: Latent class growth analysis

Abstract Consummatory successive negative contrast (cSNC) occurs when animals exposed to an unexpected downshift from a high palatable reward (e.g., 32% sucrose solution) to a less preferred one (e.g., 4% sucrose solution) show an abrupt and transient suppression of the consummatory response, compared with control animals that always had access to the less preferred one. This phenomenon constitutes an animal model of stress produced by frustrative events. To obtain information about individual differences regarding cSNC, we used Latent Class Growth Analysis (LCGA) to analyze a sample of 53 animals exposed to an incentive downshift. We found two profiles of animals, both showing the suppression of the consummatory response but diverging in the speed of the recovery. Our results are consistent with previous literature showing individual differences in cSNC and do not support the existence of a third profile.