Hierarchical nonspatial map learning in humans

Humans performed a computerized task. They learned to navigate a nonspatial maze by pressing buttons to move from one object to another. Stimuli were arranged in a hierarchy so that a root object led to 2 objects (top level) which led to 4 objects (middle level) which led to 8 objects (bottom or target level). The maze was learned by trial and error on 1-step trajectories and evaluated (without overt feedback) on full paths from root to target. We compared different curricula for learning the maze, which involved training on breadth-first, depth-first and random curricula.