The effect of flavor preexposure upon the acquisition and retention of poison-based taste aversions in deer mice: latent inhibition or partial reinforcement?

Abstract

An investigation was made of the effects of prior familiarization with sucrose on the acquisition and extinction of LiCl-induced aversions to sucrose by mice of the genus Peromyscus . As in previous studies on other species, it was found that flavor familiarization inhibits the formation of learned taste aversions. However, in contrast to some reports on other species, it was demonstrated that for Peromyscus familiarization does not accelerate, but instead retards, the extinction of taste aversions. It was noted that (a) the contrasting extinction results reported for other species may be confounded with masked acquisition effects, (b) the latent inhibition effect is often not obtained with fewer than 20 preexposures, yet the flavor-preexposure effect has been demonstrated with as few as one preexposure, (c) the flavor-preexposure schedule is logically and operationally equivalent to a short partial-reinforcement schedule, and (d) both the acquisition and extinction effects shown by Peromyscus are consistent with a partial-reinforcement interpretation. Therefore, it was suggested that future analysis of the phenomenon might profitably consider the possibility that the flavor-preexposure effect upon taste-aversion learning may be a case of partial reinforcement.