Learning-induced shifts in mice navigational strategies are unveiled by a minimal behavioral model of spatial exploration

Abstract

Shifts in spatial patterns produced during the execution of a navigational task can be used to track the effects of the accumulation of knowledge and the acquisition of structured information about the environment. Here we provide a quantitative analysis of mice behavior while performing a novel goal localization task in a large, modular arena, the HexMaze. To demonstrate the effects of different forms of previous knowledge we first obtain a precise statistical characterization of animals’ paths with sub-trial resolution and over different phases of learning. The emergence of a flexible representation of the task is accompanied by a progressive improvement of performance, mediated by multiple, multiplexed time scales. We then use a generative mathematical model of the animal behavior to isolate the specific contributions to the final navigational strategy. We find that animal behavior can be accurately reproduced by the combined effect of a goal-oriented component, becoming stronger with the progression of learning, and of a random walk component, producing choices unrelated to the task and only partially weakened in time.

Significance Statement

This work presents a novel statistical analysis we applied to describe mice behavior during a goal-reaching task in a large, modular environment (HexMaze). By combining sub-trial quantification of animal navigation with mathematical modeling of the task, we aim at developing analysis tools that can match the demands of rich, articulated experimental paradigms. We show how mice progressively incorporate information about the task and the maze structure and how such knowledge accumulation unfolds over multiple time scales. We also demonstrate how mice never completely converge to optimal behavior: even in late phases of learning a substantial part of their behavior can be ascribed to purely random choices with no relationship with the location of the goal.