Effects of post-treatment retention interval and context on neophobia and conditioned taste aversion.

We have repeatedly observed that a delay between acquisition and test, and the nature of the context in which the delay is spent, modulates latent inhibition (LI) of conditioned taste aversion (CTA; e.g. [Anim. Learn. Behav. 28 (2000) 389; Anim. Learn. Behav. 30 (2002) 112]). The present paper analysed the effects of delayed testing and treatment context after flavor exposure on the recovery of neophobia (Experiment 1) and on extinction after simple conditioning (Experiment 2). Two experiments were conducted with the same factorial design (2x2: 1 day versus 21 days of delay between first and second stage, and home versus experimental cages as place of experimental treatment). There were independent effects of both variables on habituation of neophobia and conditioning strength as measured on extinction trials. The long delay produced a reduction of neophobia (Experiment 1) and an increase in conditioning (Experiment 2). In addition, more of the flavored solution was consumed when the experimental treatment was conducted in the home cage than in the experimental cage (Experiment 1), and there was stronger conditioning when the delay period took place in the experimental cages than in the home cages (Experiment 2). The implications of these results for LI, as well as their relevance for experiments that use the CTA paradigm, are discussed.