A Cognitive Test for “Permanence.” A Modified Version for Rats

This article describes an experimental apparatus developed to evaluate solutions found by rats to the Piaget object permanence test, which assesses the animals’ ability to operate one of the simplest empirical laws, “permanence” (as defined by Krushinskii), i.e., the ability to solve an elementary logic problem. An animal placed in a brightly lit part of a chamber can escape through an underpass into a comfortable dark compartment; after the first attempt, the underpass is closed in different ways and completion of the test requires the animal to overcome an obstacle, operating with the “permanence” rule. The test does not require preliminary training and is similar to the “permanence” test used in experiments with mice. Rats of five different genetic groups were tested: outbred Wistar and Long–Evans rats, inbred Krushinskii–Molodkina (KM) rats (with a predisposition to audiogenic epilepsy), a KM-derived “0” line (without audiogenic epilepsy), and inbred SHR rats with spontaneous arterial hypertension. Preliminary experiments (performed with each animal within a single experimental day) revealed between-strain differences in test performance, SHR rats showing superior performance. This test can be used in neurophysiological and pharmacological studies of rat behavior. © 2025 Elsevier B.V., All rights reserved.