**A.2 Instructions relative to the first stage of the MS treatment (the two stages differ only by the gain associated with the choice of action A)**

For each of the 10 situations, a number **Y** is drawn randomly from a discrete uniform distribution {10, 11, 12 … ., 90}. This number is the same for all **3** participants. When you make your choice, you will not know the true value of **Y** until you decide.
