90% of the time, when a nosepoke is made on the high probability (90%) side, a Med Associates Single Speed Syringe Pump delivers ~20μl of the sweetened condensed milk and a tone plays for 0.5s to signify a correct response. 10% of the time, when a nosepoke is made on the high probability side, the house light illuminates for 7 seconds to signify an incorrect response and no reward is delivered.