Brushtail possums ('Trichosurus vulpecula') counting using response sequences under ratio reinforcement

Abstract

The aim of this study was to replicate the 'Mechner Counting Procedure' and conduct a variety of conditions to determine whether possums have the cognitive ability to count. Previous research has shown that animals are able to count the amount of responses they make and the number of light flashes that occur. Six brushtail possums participated in three conditions where FR responses were required to gain access to food reinforcement. Reinforcement was delivered either upon the completion of an FR response requirement on lever A, or on the completion of the FR on lever A, followed by an additional response on lever B. The results have shown that the possums do have the cognitive ability to count the number of responses they make. The mean response on lever B typically occurred slightly above the FR response requirement across conditions.