Fig. 1.

Effort-related choice tasks conducted in rodent operant boxes and mazes (see cited references in text for details). Left: The concurrent lever-pressing/chow-feeding choice tasks give animals the option of lever pressing on a fixed or progressive ratio schedule to obtain access to preferred high-carbohydrate pellets versus approaching and consuming freely available chow. Right: The T-maze barrier choice task presents trials that allow animals to select one arm that requires them to climb a vertical barrier to obtain a large magnitude of reinforcement versus the other arm, which has no barrier and a lower magnitude of reinforcement.