Welfare and research: automatic cognitive testing in social groups in macaques in the laboratory

Abstract

Primate cognitive behavior in the laboratory has often been evaluated by housing subjects individually or isolating them and by imposing fluid or dietary restrictions to increase the subject’s motivation to work. Advances in animal welfare have significantly changed the way in which research institutions house primates in terms of space and numbers, accompanied by enrichment programs with novel objects and food that break with traditional feeding habits. Although some could potentially see these changes as a bias to previously published data, others have already proved that it is possible to obtain remarkable scientific results while offering primates a highly enriched environment. Inspired by recent publications on automated cognitive testing in social groups, our laboratory developed a special application on tactile screens, AUTOBUNTO, by which each primate learnt its own pin code to launch a single trial of its own behavioral test. This system allows testing animals on different cognitive tests while preserving social groups in their home cages. Two tactile screens can be installed at two ends of the gang cage to avoid dominance issues over screen availability. Results suggest that gang-training to touch tactile screens is quick and that completion of different cognitive tests can be acquired in a few weeks. More importantly, primates are free to work whenever they desire it instead of being imposed with a rigid testing schedule. Isolation or dietary restrictions seem unnecessary for primates to perform cognitive tests on tactile screens. Allowing access to two tactile screens is sufficient to avoid tension within the social group. In our experience, stereotypic behavior that can appear in primates housed individually or in small social groups, is absent in the presence of tactile screens, suggesting they represent a source of environmental enrichment for primates housed in the laboratory setting.