Context-dependent reinstatement of an extinguished operant response in preweanling rats.

It is frequently assumed that infants are impaired in contextual memory and consequently, in recovery from extinction, a phenomenon considered to be context dependent. However, the evidence in the field is far from consistent with this interpretation, since several studies have shown context-dependent extinction in infant rats using a variety of procedures and behavioral measures. This discussion has primarily been based on studies using Pavlovian conditioning tasks. Three experiments were conducted to study reinstatement of an extinguished operant response and additionally to evaluate the context dependence of such an effect. Preweanling rats were trained on postnatal days (PDs) 16 and 17 to acquire an appetitive operant response using chocolate milk as reinforcer. At PD18 the operant response was extinguished and at PD19 animals received a reminder in the same (Experiment 1 and 2) or in a different context than the one used during the extinction phase (Experiment 3). Infant rats showed recovery from extinction after a reminder treatment (Experiments 2 and 3). This effect was dependent on the context in which the reminder was delivered (Experiment 3). Our results indicate that infant rats can recover an extinguished operant response by means of a reminder treatment in a context-dependent way, highlighting the importance of the context for modulating learning processes during infancy. (PsycINFO Database Record (c) 2018 APA, all rights reserved).