Figure 6:

Assessment of human and mouse probabilistic learning. During probabilistic learning, people are required to select an object based on its likelihood receiving reinforcement. One object is designated as a target while the other is designated as a non-target. Selection of the target is positively reinforced 80% of the time (“correct” for humans, a reward for animals), and not reinforced on the remaining 20% of trials (“incorrect” for humans, an omission of reward for animals), while for the non-target stimuli the contingencies were reversed. Once acquired, the contingencies are reversed. In rodents, this task can be recreated using two stimuli from 5-choice chambers. The primary outcome measures are trials to criterion. Stimuli designations can be reversed and thus, another outcome is the number of reversals achieved. Strategy assessment can also be conducted similarly to the IGT whereby the likelihood of subjects repeating a choice after a reward on the target side (target win-stay), shifting to the non-target after a loss on the target side (target lose-shift), repeating a non-target choice after being rewarded at that side (non-target win-stay), and shifting choice after punishment on the non-target side (non-target lose-shift) can be measured during the task.