Effect of Stimulus and Response Separation on Brushtail Possum Behaviour in a MTS task

Abstract

Brushtail possums, Trichosurus vulpecula, were presented with five rows of blue and yellow stimuli (levels one-five) arranged vertically 20 mm apart, above the response levers. For each level each possum was trained to complete a Matching to Sample task at zero seconds delay. Generally, possums showed peak performance at the level presently being trained across all levels. There was also a decrease in performance at levels further from the trained level, suggesting performance generalised to similar levels. The findings from this experiment provide evidence for placing stimuli and response manipulanda close together to improve acquisition of a task, and increase the responding accuracy in DMTS experiments. This suggests that the relative position of stimuli and response manipulanda is critical to possums performing a MTS task. These findings also have implications for experiments other than MTS and could be applied to study involving other marsupials.