<p>Levels of attention to moving objects, neophagy, and manifestations of short-term memory were assessed in mice of two strains, selected for success (the plus strain) and failure (the minus strain) in solving a puzzle-box test to assess the ability to understand “object permanence” (as defined by Piaget). In the most difficult version of the permanence test, when the underpass through which the animal could hide in the darkness from the brightly lit chamber was closed with a plug, mice of the plus strain showed (within just a small number of generations) a significant difference in this characteristic from mice of the minus strain. This article presents data demonstrating the better performance of plus mice in a test for attention to novel moving objects, as well as in their positive reactions, as compared with those of minus mice, to novel food in a novel environment (neophagy). Plus mice also differed significantly from minus mice in terms of the manifestations of short-term working memory. The time taken to solve the second presentation of the plug test, as compared with the latency of the first presentation, was shorter in a greater proportion of plus animals than minus animals. It is suggested that the between-strain differences found here can be attributed to differences in the expression of executive functions in these animals.</p>