Discussion of nunuphar's comment: I think if their goal is to really flesh out the mechanisms by which learning by DA RPE signaling occurs I would find it much more illuminating if they would have recorded from the DA neurons and other parts of the learning circuit while the animals did the task to see how the DA neuron bursting and pausing affected other parts of the circuit. Additionally, while they did the stimulation I’m not sure that the effect of their stimulation was as simple as they assume resulting in the perfect cancelling out of the DA pause in the extinction case and a simple burst in the blocking task, so recording during this time would be useful.