Occasion Setting in Animal Cognition Research: Some Unaddressed Issues

Holland and colleagues introduced the concept of occasion setting in the 1980s, revolutionizing Pavlovian conditioning research by highlighting the hierarchical properties of stimulus control.Occasion setting involves a stimulus that modulates the association between a conditioned stimulus and an unconditioned stimulus.Building on this, Leising et al. ( 2025) applies the concept to a broader range of behaviors and cognitive processes, from Pavlovian and instrumental conditioning to theory of mind and language.However, their article leaves several areas requiring further discussions: (a) the effects of temporal gaps between feature and target stimuli on discrimination performance, (b) contextual control in flavor aversion learning, (c) contextual control in spatial learning, (d) mathematical modeling of occasion setting, and (e) the limits of understanding hierarchical event structures in nonhuman animals.Addressing these issues will refine the theoretical and practical understanding of occasion setting across disciplines.