RAT VILLAGE: A FULLY AUTOMATED HOME CAGE TESTING SYSTEM TO STUDY RAT COGNITION

Understanding the cognitive mechanisms underlying working memory and numerical decision-making requires behavioural platforms that generate large, reliable datasets while minimising experimenter interference. Traditional rodent paradigms rely on manual handling and scheduled sessions, introducing variability and limiting reproducibility. We developed the Rat Village, a fully automated and enriched home-cage testing system that enables rats to voluntarily initiate touchscreen-based cognitive tasks, providing continuous, high-throughput data collection with minimal human involvement. The Rat Village consists of enriched home cages connected via a corridor system to an operant touchscreen chamber that permits only one rat to enter at a time to go to the behavioural box. Using this platform, we implemented a visuospatial delayed-response task to assess working memory and a two-alternative forced choice task to evaluate numerical decision-making under Weber’s Law. Rats traversed a bridge equipped with photogates that controlled the disappearance of the stimulus, allowing systematic manipulation of short, medium, and long delay intervals. For numerical discrimination, rats chose between two options associated with large token populations that differed in ratio, preventing reliance on small-number discrimination strategies. Working memory accuracy declined with increasing delay, and numerical accuracy improved as the ratio between probabilities increased. These results suggest that rats use an approximate number system and follow Weber’s Law. Together, these findings validate the Rat Village as a robust and scalable platform for studying working memory and decision-making under standardised, welfare-friendly conditions and establish a foundation for future investigations into probabilistic inference and cross-species comparisons.