The impact of changeability of enriched environment on exploration in rats

Abstract Although the positive effect of environmental enrichment on animals’ cognitive capacities is well-known, it remains unclear what role changeability plays in this context. Our study aims to analyse the impact of environmental changeability on the level of exploration and the rate of habituation to novelty. Prior to the experiment, the animals were housed in three settings: enriched stable conditions, enriched changing conditions and standard conditions. Environmental changeability was introduced by re-arranging objects in the housing pen. A test was conducted to measure the level of exploration in adult individuals. The study results suggest that rats housed in standard conditions exhibit a higher demand for interactions with the new environment. However, once novelty is introduced, rats from the enriched environments spend more time than their standard counterparts exploring the new objects. No significant differences have been observed in the behaviour of rats from the stable and changeable conditions. It may be concluded, therefore, that in a setting characterised by long-lasting environmental enrichment, the changeability of the environment plays no major role, at least with respect to exploration, general activity and the rate of habituation to novelty. It may be linked to the relatively quick extinguishment of behaviours reinforced by intrinsic reinforcement.