Can lemurs (Eulemur fulvus and E. macaco) use abstract representations of quantities to master the reverse-reward contingency task?

Abstract

In previous studies we demonstrated that brown and black lemurs (Eulemur fulvus and E. macaco) showed self-control abilities under a reverse-reward contingency. They were able to significantly select the smaller quantity of food to be rewarded with the larger one and to generalize this ability when presented with two rewards that differed in quality. In the present study, previously trained subjects had to choose between graphic representations of two different quantities of food under the reverse-reward contingency. Three out of four subjects learned to associate a graphic representation of the reward with the corresponding quantity. Only one subject consistently selected the representation of the smaller quantity to be rewarded with the larger quantity of food and therefore showed abstraction as well as relative numerousness skills. Indeed, she was able to discriminate between representations of different quantities and to ordinate them. We discuss how primates mentally represent food quantities and how self-control is involved in foraging strategies.

Phylogenetic comparison on cognition: Advances in evolutionary psychology

“…有研究者总结了数量认知能力的演化证据 [31] , 特 别是现有研究显示在灵长目物种中, 包含原猴 [32,33] 、 狨 [34,35] 、猕猴 [36~38] 、狒狒 [39,40] 、大猿 [40~42] 等都表现出 了一定的数量认知能力. 而且数量认知能力也具备基 础认识能力的特点 [43] , 即可以从自上而下的角度对数 量认知能力进行研究.…”

Convergent evolution of complex brains and high intelligence

“…They also learned to associate a graphic representation of the reward with the corresponding quantity, even though only one subject consistently selected the representation of the smaller quantity to be rewarded with the larger quantity of food [67]. The fundamentals of abstraction appear to be present in prosimians.…”

“…Lemurs are capable of controlling their impulsive gesture towards a larger option, when selection of a smaller quantity of food is rewarded with a larger one. They also learned to associate a graphic representation of the reward with the corresponding quantity, even though only one subject consistently selected the representation of the smaller quantity to be rewarded with the larger quantity of food [67]. The fundamentals of abstraction appear to be present in prosimians.…”