According to the 'mental time travel hypothesis' animals, unlike humans, cannot mentally travel backwards in time to recollect specific past events (episodic memory) or forwards to anticipate future needs (future planning). Until recently, there was little evidence in animals for either ability. Experiments on memory in food-caching birds, however, question this assumption by showing that western scrub-jays form integrated, flexible, trial-unique memories of what they hid, where and when. Moreover, these birds can adjust their caching behaviour in anticipation of future needs. We suggest that some animals have elements of both episodic-like memory and future planning.
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This research was supported by grants from the National Institutes of Health and the Grindley Trust to N.S.C. and a BBSRC grant to N.S.C. and A.D., and conducted within a UK Medical Research Council Cooperative Grant. We thank S. de Kort, N. Emery, R. Morris and T. Robbins for comments and discussion. Special thanks go to N. Emery for his original artwork, and to I. Cannell for his photographic skills.
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Clayton, N., Bussey, T. & Dickinson, A. Can animals recall the past and plan for the future?. Nat Rev Neurosci 4, 685–691 (2003). https://doi.org/10.1038/nrn1180
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