Figure 1. Illustration of instrumental tasks used to assess goal-directed decision making.

In both tasks, animals are first trained to associate two actions (left vs. right nose-pokes) with delivery of two distinct reinforcers (yellow vs. grey pellets). (A) Illustration of outcome devaluation. Immediately prior to a choice test, animals are allowed to freely consume one of two the pellets (e.g. grey pellet) thus decreasing the value of that outcome. (B) Choice test responding whereby goal-directed action is defined by a preference for the nose-poke aperture associated with the valued vs. devalued pellet. (C) Illustration of contingency degradation. Animals undergo a session in which one action (e.g. nose-poking on the left) is reinforced as during training, while the other action (e.g. nose-poking on the right) is no longer linked to reinforcer deliver and instead the pellet associated with that action (e.g. grey pellet) is non-contingently (or “for free”). (D) Choice test responding whereby goal-directed action is defined by a preference for the nose-poke aperture associated with the previously reinforced vs. degraded contingency.