Synergistic Benefits of Group Search in Rats

Abstract

Locating unpredictable but essential resources is a task that all mobile animals have to perform in order to survive and reproduce. Research on search strategies has focused largely on independent individuals [1Vergassola M. Villermaux E. Shraiman B.I. ‘Infotaxis’ as a strategy for searching without gradients.Nature. 2007; 445: 406-409Crossref PubMed Scopus (518) Google Scholar, 2Bartumeus F. Peters F. Pueyo S. Marrasé C. Catalan J. Helical Lévy walks: adjusting searching statistics to resource availability in microzooplankton.Proc. Natl. Acad. Sci. USA. 2003; 100: 12771-12775Crossref PubMed Scopus (225) Google Scholar, 3Gire D.H. Kapoor V. Arrighi-Allisan A. Seminara A. Murthy V.N. Mice develop efficient strategies for foraging and navigation using complex natural stimuli.Curr. Biol. 2016; 26: 1261-1273Abstract Full Text Full Text PDF PubMed Scopus (53) Google Scholar], but many organisms display collective behaviors, including during group search and foraging [4Gregor T. Fujimoto K. Masaki N. Sawai S. The onset of collective behavior in social amoebae.Science. 2010; 328: 1021-1025Crossref PubMed Scopus (217) Google Scholar, 5Bhattacharya K. Vicsek T. Collective foraging in heterogeneous landscapes.J. R. Soc. Interface. 2014; 11: 20140674Crossref PubMed Scopus (24) Google Scholar, 6Flack A. Nagy M. Fiedler W. Couzin I.D. Wikelski M. From local collective behavior to global migratory patterns in white storks.Science. 2018; 360: 911-914Crossref PubMed Scopus (74) Google Scholar]. One classical experimental search task, informing studies of navigation, memory, and learning, is the location of a reward in a confined, complex maze setting [7Olton D.S. Collison C. Werz M.A. Spatial memory and radial arm maze performance of rats.Learn. Motiv. 1977; 8: 289-314Crossref Scopus (295) Google Scholar, 8Walf A.A. Frye C.A. The use of the elevated plus maze as an assay of anxiety-related behavior in rodents.Nat. Protoc. 2007; 2: 322-328Crossref PubMed Scopus (1600) Google Scholar]. Rats (Rattus norvegicus) have been paradigmatic in psychological and biological studies [9Tolman E.C. Cognitive maps in rats and men.Psychol. Rev. 1948; 55: 189-208Crossref PubMed Scopus (3490) Google Scholar, 10Pearce J.M. Animal Learning and Cognition: An Introduction. Psychology Press, 2013Crossref Scopus (29) Google Scholar], but despite rats being highly social [11Barnett S.A. An analysis of social behaviour in wild rats.Proc. Zool. Soc. Lond. 1958; 130: 107-152Crossref Scopus (193) Google Scholar, 12Calhoun J.B. The Ecology and Sociology of the Norway Rat. US Department of Health, Education, and Welfare, Public Health Service, 1963Crossref Google Scholar], their group search behavior has not been investigated. Here, we explore the decision making of rats searching individually, or in groups, for a reward in a complex maze environment. Using automated video tracking, we find that rats exhibit—even when alone—a partially systematic search, leading to a continuous increase in their chance of finding the reward because of increased attraction to unexplored regions. When searching together, however, synergistic group advantages arise through integration of individual exploratory and social behavior. The superior search performances result from a strategy that represents a hierarchy of influential preferences in response to social and asocial cues. Furthermore, we present a computational model to compare the essential factors that influence how collective search operates and to validate that the collective search strategy increases the search efficiency of individuals in groups. This strategy can serve as direct inspiration for designing computational search algorithms and systems, such as autonomous robot groups, to explore areas inaccessible to humans.Video AbstracteyJraWQiOiI4ZjUxYWNhY2IzYjhiNjNlNzFlYmIzYWFmYTU5NmZmYyIsImFsZyI6IlJTMjU2In0.eyJzdWIiOiJkZGU1YTU1NjFmZTg4OWQzNzZlNGQ4YjFmMDllMDczNCIsImtpZCI6IjhmNTFhY2FjYjNiOGI2M2U3MWViYjNhYWZhNTk2ZmZjIiwiZXhwIjoxNjYyNzA5NTU2fQ.Jf95t-h_EBto6iia8yz9Ji7ImR847k3ie1r3M4tUaRS-KmRDXq8TveFO0ymnxC03ItXfQ4kpwnnGB6ElEvP6v4SsT6sfue3Wkm3zKybzr0-IyCcscYoFlB_mncfaLUc1YJhjbVS91wTj8YowAUGj0ccBDfJ-_vog5fhSBLrKjE91K0mogJDJG9seG-_xXlI5Gm061Ouh4kHTRhwZWN5qcNbW0AfjLgrDafQFACrPBAwhy3p2ZVepNOG4qPWjN9RgB1wr5MD3YqefPfrA-SdRrg8I4sVJEWp3t9s7IXaZ11h6em4LlzYabqylVBNrazRxSEPKfmNXz7IjGwep_QeGAg(mp4, (30.87 MB) Download video

Topics & Concepts