Memory alone does not account for the speed of learning of a simple spatial alternation task in rats.

Animal behavior provides context for understanding disease models and physiology. However, that behavior is often characterized subjectively, creating opportunity for misinterpretation and misunderstanding. For example, spatial alternation tasks are treated as paradigmatic tools for examining memory; however, that link is actually an assumption. To test this assumption, we simulated a reinforcement learning agent equipped with a perfect memory process. We found that it is unable to learn a simple spatial alternation task as rapidly as a group of male rats, illustrating that memory alone may not be sufficient to capture the behavior. We demonstrate that incorporating spatial biases permits rapid learning and enables the model to fit rodent behavior accurately. Our results suggest that even simple spatial alternation behaviors likely reflect multiple cognitive processes and that complexity needs to be taken into account when studying animal behavior. Significance statement Memory is a critical function for normal cognition whose impairment has significant clinical consequences. Experimental model systems aimed at testing various sorts of memory are therefore also central. However, experimental designs to test memory are typically based mainly on intuition about the underlying processes required. We tested this using a popular system: spatial alternation tasks in rats. Using behavioral modeling, we show that the most straightforward intuition that these tasks just probe spatial memory, does not account for the speed with which rats learn. Only when memory-independent dynamic spatial preferences are added can the model learn as rapidly as the rats. This highlights the importance of respecting the complexity of animal behavior to interpret neural function and validate disease models.