Evaluating inhibitory control in captive raccoons (Procyon lotor) using the cylinder task

Inhibitory control is an executive function that allows humans and non-human animals to inhibit a prepotent response and persist in goal-directed behavior when outcomes are delayed. In non-human animals, inhibitory control has been proposed to be an important component of behavioral flexibility, where animals must inhibit previously used behaviors in order to establish new ones. The cylinder task has become a widely used, detour-reaching task to test inhibitory control in many non-human animal species. Here we directly test inhibitory control in raccoons for the first time using a modified version of the cylinder task. Raccoons have demonstrated behavioral flexibility traits such as repeated innovation and reversal learning but have not been tested in inhibitory control specifically. Five wild-caught, captive raccoons participated in the familiarization and detour procedures of the cylinder task, and we found an overall 60% pass rate in their cylinder task performance. We used k-means clustering to compare raccoons to other species tested in the cylinder task and found that raccoons cluster in the moderate performance group. Raccoons’ expression of persistence may lead to their moderate cylinder task performance while benefiting them in other traits related to behavioral flexibility, such as problem solving.