Avoidance differences between rats and gerbils

Abstract

Gerbils and rats learned equally well to discriminate the lighted, safe arm from the unsafe arm during Y-maze avoidance trials. Gerbils, however, were inferior to rats in initiating this response in time to avoid shock. Two subsequent experiments on passive avoidance did not support the interpretation of these data based on a greater incidence of shock-induced activity suppression in gerbils. In both experiments, gerbils required more shocks than rats to learn a staying response, indicating a pronounced locomotor response bias in gerbils that is not compatible with the required passive avoidance response. A fourth experiment, using a shuttlebox, found that the relative active avoidance performance by these species depends upon whether intertriai responses are permitted and punished. When they are, gerbils are inferior to rats, since their high level of locomotor responding is not compatible with the behavior required, i.e., staying during the intertrial interval and running during the CS-US interval. On the other hand, gerbils are not inferior when intertrial responses are prohibited, since their locomotor bias is not punished and is compatible with the required avoidance response. © 1976 Psychonomic Society, Inc.