Intrinsic prospective motives in non-human primate food consumption behaviour

Abstract

Abstract Behaviours that are regulated with future goals and drive states in mind are regarded as cornerstones of human cognition. One key phenomenon through which future-orientation can be studied is the delay of gratification, quantified by the waiting time for which an individual withstands the consumption of an immediate reward to achieve a larger reward available after a certain delay. The delays used in animal delayed gratification paradigms are rather short to be considered relevant for studying human-like future-orientation. Here, for the first time, we show that rhesus macaques exhibit human-relevant future-orientation downregulating their operant food consumption in anticipation of a nutritionally equivalent but more palatable food with an unprecedentedly long delay of approx. 2.5 hours. This behaviour was not learnt gradually through conditioning but was readily displayed after a single exposure to a two-session “worse-now & better-later” food schedule. Importantly, no food choice was directly imposed by the experiment itself, but the animals intrinsically adjusted their behaviour to their satiation dynamics across the sessions, demonstrating their superior ability to anticipate future drive states. Our results have a strong implication that the cognitive time horizon of primates, when faced with ecologically valid foraging-like experimental situations, extends much further into the future than previously considered. In agreement with past observations from the broader perspective of animal foresight and planning, the present findings open new avenues that up till now have been opaque for translational biomedical research.