The incentive value of a natural and cognitively demanding behaviour: food-caching jays as a model system

这项研究的总体目标是研究动物做出自然的、对认知要求高的行为时，内在的奖赏是如何的。我们将研究的行为是松鸦的一种谋生行为，即隐藏食物以备将来食用，并依靠记忆在以后找到隐藏的藏身之处(“食物缓存”)。从福利的角度来看，人们对对圈养动物使用认知丰富(即为它们提供具有智力挑战的任务)的兴趣越来越大，但缺乏关于认知活动是否以及如何对动物本身产生回报的科学证据。拟议的研究直接解决了这个问题，调查了鸟儿最有动力进行哪些方面的缓存行为(即鸟儿最看重)，以及这些决定如何受到行为的认知属性的影响，例如鸟儿对成功恢复的可能性的了解，以及鸟儿当前或预期的动机状态。为了解决这些问题，我们将为松鸦制定一个决策范例，在两个栖息地之间的选择决定了进入两个笼子中的一个。Jay将在这些笼子中不同数量的缓存位置之间进行选择，以确定它们对缓存机会的偏好是否因它们的饥饿度而增强，以及它们对缓存的重视是否也取决于它们是否最近或在更长的时间段内被阻止缓存。我们还将调查鸟类的选择是否也受到它们找回藏品时发生的事情的影响。这一点很重要，因为为了使恢复条件影响鸟儿的缓存偏好，鸟类必须根据它们过去恢复缓存的经验来预测这些条件。为了测试这一想法，我们将确定Jay是否对它们有机会找回的地方的缓存赋予了更高的价值，以及它们是否对缓存以前被盗或变质的一种食物赋予了较低的价值。我们还会问，它们在缓存时或在恢复缓存时的觅食动机是否会影响它们缓存的机会，以及它们是否比其他可能目睹缓存事件并因此对其缓存构成威胁的鸟儿更重视私下缓存。综上所述，这些实验将提供有关Jays做出的缓存决定以及这些决定受到认知和动机因素影响的程度的重要信息。因此，它将揭示这种自然行为在不同动机和认知条件下的回报表现如何影响缓存行为的结果。通过提供有关执行认知要求高的任务的价值的新信息，该项目将使我们能够调查在福利改善计划中使用“认知丰富”的理由和潜力。

The overall objective of this research is to study how inherently rewarding it is for an animal to perform a natural and cognitively demanding behaviour. The behavior that we will study is one that jays do for a living, namely hiding food for future consumption and relying on memory to find hidden stashes at a later date ('food-caching'). From a welfare perspective, there is increasing interest in using cognitive enrichment for captive animals (i.e. providing them with tasks that are mentally challenging), but there is a lack of scientific evidence as to whether and how cognitive activities are rewarding to animals per se. The proposed studies directly address this issue by investigating what aspects of caching behaviour the jays are most motivated to perform (i.e. the jays value the most), and how these decisions are influenced by the cognitive attributes of the behaviours, such as the jays' knowledge of the likelihood of successful recovery, and the bird's current or anticipated motivational state. To address these issues, we shall develop a decision paradigm for the jays in which the choice between two perches determines access to one of two cages. The jays will be given a choice between differing numbers of cache locations in these cages to find out whether their preference for the opportunity to cache is enhanced by how hungry they are, and whether the value they place on caching also depends on whether or not they have been prevented from caching either recently, or over longer time periods. We shall also investigate whether the birds' choices are also modulated by what happens when they come to recover their caches. This is important because in order for the recovery conditions to affect the jays' caching preferences, the birds must anticipate these conditions on the basis of their past experience of recovering their caches. To test this idea, we shall determine whether or not jays assign a higher value to caching in places from which they have the opportunity to recover and whether they assign a lower value to caching a type of food that has previously been stolen or has become spoiled. We shall also ask whether the opportunity to cache is affected by their feeding motivation at the time when they cache or when they come to recover the caches, and whether they value caching in private more than when others jays are present who could witness the caching event and therefore pose a threat to their caches. Taken together these experiments will provide important information about the caching decisions that jays make and the extent to which these decisions are influenced by cognitive and motivational factors. It will thus reveal how rewarding performance of this natural behavior is under different motivational and cognitive conditions that influence the outcome of caching behavior. By providing new information about the value of performing a cognitively demanding task, the project will allow us to investigate the rationale and potential for using 'cognitive enrichment' in welfare enhancement programmes.