The memory we miss: exploratory behavior as a window into developmental recognition processes

Recognition memory tasks are among the most widely used approaches for studying learning and memory across the lifespan, yet the behavioral measures used to assess memory, particularly during developmental studies, remain limited. In most rodent studies, recognition memory is inferred almost exclusively from discrimination ratios or indices that quantify preferential exploration of novel stimuli. While these measures are valuable, their widespread use may constrain our understanding of the cognitive-behavioral processes supporting nuanced memory expression across ontogeny. Similar concerns have emerged in fear conditioning, where expanding analyses beyond freezing behavior revealed previously unrecognized differences in memory. In this perspective, we argue that recognition memory research would benefit from expansion of behavioral analyses. Drawing on affordance-based approaches to object exploration, we discuss evidence showing that object properties influence memory performance and exploratory behavior. Importantly, our recent findings indicate that pre-weanling (but not adult) rats exhibit task-dependent shifts in exploratory behavior, contingent on the object's affordances, which are not captured by traditional discrimination measures. These findings suggest that developmental differences in memory may be expressed not only through recognition performance but also through the exploratory strategies animals employ during retrieval. Expanding behavioral analyses in recognition tasks may therefore reveal developmental neurobehavioral mechanisms that remain hidden from conventional metrics, providing a more complete understanding of memory development. The challenge moving forward is not simply to determine whether young animals remember, but to identify how they remember and whether the behavioral routes to successful memory change across development.